TW556440B - Method and device for preventing trapezoidal distortion in projected image - Google Patents

Abstract

The present invention provides a method and device for preventing the trapezoidal distortion in the projection image, wherein the projection light from the light source (102) passes a deformed image (700a) to generate a projected image (750a) to be exhibited on the display device (110) of the projector (100), and exhibited on a screen (130) in a non-vertical angle; the received original image (700) to be projected is proportional to the angular deformation of the project to generate the deformed image (700a), so that the projection can generate the projected image (750a) in a ratio closely matched with the original image (700). The original image (700) can be adjusted with the size to be stored in a storage and/or fitted in a specific area of the display (110). The device further includes a numerical conversion module (206) for receiving the original image (700) and adjusting the size for storage; and, a generator module (208) for adjusting the size of the image to be fitted with the display (110). The deformation of the original image (700) can be executed in either one or both of the numerical device (206) and the generator (208).

Description

Revised date 92.6 · 30 08168twfl.doc / 006 玖, description of the invention: Background of the invention The present invention relates to image processing and projection technology, and in particular to a computer-controlled projection system and method provided by a projection without trapezoidal Distorted image system. Image projectors or projection systems are often used to produce an enlarged version of a video image. For example, the original image can be presented on an LCD (liquid crystal display) or other device through which light can be projected onto a display screen in order to enlarge or enlarge the original image. The projection system is calibrated to project an image perpendicular to the screen, and the projected image can accurately reproduce the proportion of the original image. However, projection systems are often placed at an angle to the display. As a result, the projected image is often disturbed by what is called keystone distortion, and therefore may be substantially different from the original image. Specifically, when the projection straight axis of the system is not perpendicular to the video screen, a part of the projected image may be distorted (such as extended or compressed). For example, if the projector is placed below a straight line perpendicular to the screen's field of view, the image must be projected upwards onto the screen. As a result, the upper part of the image may expand or extend relative to the bottom part, or the bottom part of the image may shrink or shrink compared to the upper part. The image thus projected may have the shape of a trapezoid or a vault. Similarly 'if the projector is placed above or on one side or other position perpendicular to a line of the video screen, different parts of the projected image may appear distorted. According to the clarity or detail of the projected image, this distortion may seriously worsen people's recognition of the 08168twf1.doc / 006 date of revision 92.6.30 ghai. Due to short-term or temporary use of the device, lack of space in front of the screen, such as the projector being placed perpendicular to the center of the screen, which may prevent people from viewing, and other reasons, the projector may be placed at a non-vertical angle to a screen. As the projector moves further away from the screen, there may be a larger projected image 'but the keystone distortion increases in proportion. One approach to this trapezoidal distortion problem involves using mechanical compensation. In the method, the LCD panel in which the original image is provided and transmitted through it so as to produce the projected image can be rotated so that it is positioned in parallel with the plane on which the screen is located. However, this solution is expensive and requires manual adjustments for different environments. Every time the position of the video screen or projector changes, the LCD panel may need to be mechanically adjusted. Completion of this type of calibration therefore takes time and is related to the manual agility of the operator. In addition to the trapezoidal distortion problem, some projection systems combine multiple 1 ^ (:: 0 panels (such as one for each of the three primary colors) to improve image quality. In this case, the system was relatively increased Complexity and further complicates keystone distortion correction. In addition, current LCD projector systems lack the ability to easily modify useful images, such as modifying the brightness equalization or variably adjusting the size of the image. Invention SUMMARY OF THE INVENTION In one embodiment of the present invention, a system and method for adjusting an image is provided for projecting an image without keystone distortion, wherein the projection system is calibrated to be non-uniform with respect to a plane on which the image is projected. Vertical $ degrees. In this embodiment, if necessary, an original image is resized 08168twf1.doc / 006 correction date 92 · 6 · 3 (3 inches, and reshaped in order to compensate otherwise possible in the figure Keystone distortion that occurs during the projection of an image. Specifically, an original image may be electronically deformed or adjusted to provide an image within a projector or projection system. Or multiple LCDs. The distorted image is structured so that when projected on a video screen, the reconstruction of the original image has an enlarged or enlarged ridge, and the proportion of the original image is maintained, but no obvious In this embodiment of the invention, the vertical compensation of the projection device (for example, the device is rotated vertically with respect to the horizontal axis) results in an elevation angle between the projection axis of the device and a straight line perpendicular to the video screen. β. The # image in this case is projected up or down onto the video screen. Similarly, a pan angle α is generated from the horizontal compensation of the device (eg the device is rotated horizontally about the vertical axis). When one or both of the elevation angle 0 and the scanning angle α are not equal to zero, the necessary deformation operation may be performed separately or in combination. In one embodiment of the present invention, a device for preventing keystone distortion includes a digitizer A module in which an original image is resized (eg, decimated or reduced) for storage in a memory, and a generator module in which the stored image is adjusted Dimensions (such as enlargement or expansion) for providing on a display device (such as an LCD panel). Can be performed in either or both of these modules to compensate or prevent keystone distortion in image distortion. If the elevation angle is 0 And both the scanning angle α are non-zero, the image can be deformed for one angle and then rotated (eg, ninety degrees) and deformed to compensate for another angle. In one embodiment of the present invention, it is performed to prevent or compensate for trapezoidal distortion. The degree and effect of the distortion can depend on a number of factors. These factors 556440 modify the date 92 · 6 · 3 0 08168twf1. Doc / 006 can include an elevation angle of 0 or a sweep angle α, from the projection light source to the display device (such as LCD Board), the dimension of the original image, the dimension of the available domain of the display device, and so on. An original image may be distorted line by line, pixel by pixel, or on some other basis. In one embodiment of the present invention, several parameters are calculated in order to indicate the available fields of the display device, the number of lines in an image to be provided and projected, the position (e.g. pixels) in each line, and the like. Subsequently, for each selected or useful portion (eg, a pixel) of the display device, a corresponding portion of the original image (eg, a pixel or group of pixels) is labeled by applying one or more geometric or mathematical relationships. The characteristics (eg, color, intensity) of a corresponding portion of the original image may then be added to a selected portion of the display device. As a result of deforming an original image and replicating its characteristics, the image projected on the screen presented on the display device can reproduce the proportion of the original image (at an enlarged scale) without a significant or perceptible trapezoid distortion. In an alternative embodiment of the present invention, the method and apparatus of the present invention further provide for ensuring a uniform illumination intensity of the projected image. Specifically, the light intensity of an image presented on a display device which is reused for projecting a target may be attenuated or adjusted inversely in order to equalize the light intensity of the image. Brief description of the drawings: Figure 1A shows the projection system calibrated to project a keystone-free image; Figure 11D shows the problem of keystone distortion in a projection system that is not aligned vertically with a video screen. FIG. 2 is a block diagram of a device for preventing keystone distortion in a calibration projection system according to an embodiment of the present invention for preventing a non-zero 8168twf1.doc / 006 correction date 92.6.30; FIGS. 3A-3C Figure 2 shows the digitizer part of the device of Figure 2 and its operation on an original image according to an embodiment of the invention; Figures 4A-4B show the generator part of the device of Figure 2 and its embodiment according to the invention Operations on a stored image; Figures 5A-5D show an alternative embodiment of a device for preventing keystone distortion according to an alternative embodiment of the invention; Figures 6A-6B show a suitable one for implementing the invention A side view and a top view of the projection system of the embodiment; FIG. 7A is a diagram showing the principle of obtaining a display image from an original image according to an embodiment of the present invention; FIG. 7B is a diagram showing a Example A projection image generated from the display of FIG. 7A and the original image, and FIGS. 8A-8G are compensation display images according to an embodiment of the present invention; and FIGS. 9A-9B are suitable for implementing the present invention. A side view and a top view of a projection system according to an embodiment of the present invention; FIG. 10 shows a combined original image size adjustment and deformation performed by a digitizer according to an embodiment of the present invention; and FIGS. 11A-11B show The embodiment of the invention is the size adjustment and deformation of the image by the generator; FIG. 12 is a block diagram showing a device constructed according to the embodiment of the invention, when the projector and a line perpendicular to the video screen exist Horizontal and vertical angles are used to prevent keystone distortion. 08168twf1. Doc / 006 Revised date 92.6.30 Figures 13A-13D are obtained by displaying a display image according to an embodiment of the present invention when the projector and When there are horizontal and vertical angles between the straight lines of the screen, a display image is obtained from the original image. Figures 14A-14F are optional results of displaying a display image according to an optional embodiment of the present invention. vertical A display image is obtained from the original image when there are horizontal and vertical angles between the straight lines of the video screen; Figures 15A-15E are optional results showing a display image according to an optional embodiment of the present invention. A display image is obtained from the original image when there are horizontal and vertical angles between the projector and a straight line perpendicular to the video screen; Figures 16A-16B show a reduced size or center according to an embodiment of the present invention Prevention of keystone distortion in a display image that is placed away from; Figures 17A-17B show the prevention of keystone distortion in a display image that is reduced in size or centered according to an embodiment of the present invention; Figures 18A-18C show the equalization of the light intensity of an original image according to an embodiment of the present invention; Figure 19 shows a method and flowchart according to an embodiment of the present invention to obtain a display from an original image An image, even with keystone distortion, can be used to project a display image with little keystone distortion; Figure 20 is a flowchart according to an embodiment of the present invention to demonstrate the determination of the effective area of a displayed image Method; FIG. 21 is a flowchart according to an embodiment of the present invention, and demonstrates a method for obtaining a display image from an original image; 556440 08168twf1. Doc / 00β Modification date 92.6.30 FIG. 22 is an implementation according to the present invention The example flowchart shows an alternative method of obtaining a display image from an original image. Figure 23 is a flowchart according to an embodiment of the present invention, showing that when the horizontal and vertical angles of the projection system are non-zero, A method for obtaining a display image from an original image; and FIG. 24 is a flowchart according to an embodiment of the present invention, which demonstrates the method and the method for equalizing the brightness of an image by attenuating its light intensity. Simple explanation of the drawing number = 100 projector 102 light source 104 projection axis 106 focal length 110 LCD panel-120, 350, 700, 1000, 1400, 1500 original image 122 original image plane 130 screen 140 screen image 200 device 202 CPU interface 204, 1220 memory interface 206, 1201 digital device 208, 1250 generator 302 image receiver 304 reducer 10 556440 08168twf1.doc / 006 Date of revision 92 · 6 · 3.

306, 508, 512, 1206, 1236 Adjuster 308, 510, 1208, 1238 Keystone module 310 Controller 352 Original-X 354 Original-Y 360, 1100, 1120 Reduced image

362 Write-X

364 Write-Y

366 Start-Write-X

368 Start-Write-Y 370 Distorted image 402, 1202, 1232 image receiver 404, 1234 interpolator 406, 1210, 1240 controller 450 stored image

452 Read-X

454 Read-Y

456 Start-Read-X

458 Start-Read-Y

460, 700a, 1002, 1104, 1802 Display image 462 Display-X 464 Display-Y 750 Original image projected 750a Display image projected

II 08168twf1.doc / 006 Revised Date 92 · 1102 Enlarged Image 1602 Display Device 1804 Projected Image 1900-2416 Detailed description of the steps The description given below enables those skilled in the art to make and use the invention and provides it Within the scope of the invention and the specific application of its specifications. Various modifications of the embodiments of the present disclosure will be readily apparent to those skilled in the art, and the general principles defined therein can be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown, but to follow the widest scope consistent with the principles and features disclosed therein. The programming environment of one of the illustrated embodiments of the present invention is illustratively implemented in conjunction with a general purpose computer or special purpose computing device. The operational details of such devices (e.g., processor, memory, data storage) are well known 'and are omitted for brevity. It should be understood that the techniques of the present invention can be implemented using a variety of techniques. For example, the methods described therein can be implemented in software executing on a computer system, or in a combination of microprocessors or other application specific integrated circuits, specially designed hardware with programmable logic devices, or various combinations thereof. Specifically, the methods described therein may be implemented by a series of computer-executable instructions residing on a storage medium, such as a carrier wave, a disk drive, or a computer-readable medium. Exemplary carrier forms may take the form of electrical, electromagnetic, or optical signals that transmit digital data streams along a local network or a publicly accessible network, such as the Internet. 556440 Rev. 92.6.30 〇8168twf1.doc / 006. Various devices and methods for projecting an image on a video screen or other plane in a manner that minimizes or eliminates keystone distortion are described below. As will be seen, other application effects can be equally good, such as adjustment of sharpness, contrast, position, and other characteristics of an image. One or more embodiments of the present invention are directed towards a projection system in which light is projected onto a video screen through an original image. The original image may be presented on a transparent or translucent device, such as one or more liquid crystal displays (LCDs). Those skilled in the art will recognize that if the orientation of a projection system is such that the axis of the projection light source is perpendicular and perpendicular to the original image and the center of the screen, there will be no trapezoidal distortion in the projection image. However, where the projection system is placed at a non-vertical horizontal and / or vertical angle to the video screen (any of which is adjustable), embodiments of the present invention can be applied to prevent or minimize the keystone distortion . The embodiments of the invention described therein are applicable to both front and rear projection systems. In one embodiment of the invention, the projection device is oriented at a non-orthogonal angle to a video screen, and a method of preventing keystone distortion is as follows. An adjusted or distorted image is generated from an original image to be projected, and when presented on an LCD panel and projected on the screen, an enlarged view of the original image is produced with little or no keystone distortion. The distorted image can be considered to compensate or avoid the keystone distortion that would otherwise be generated from the orientation of the projection system. In terms of thought, 'If the original image appears enlarged on the screen without noticeable keystone distortion, the distorted image provided on the LCD panel 13 08168twf1.doc / 006 correction date 92.6.30 is this A perspective view of the original image where keystone distortion was noticeable. The perspective view is obtained somewhere between the screen and the projection light source-for example, within the plane of the LCD panel. Keystone distortion can be better understood by referring to Figures 1A-1D. Figure 1A shows a projection system in which the projection axis 104 of the projector 100 (represented by the light source 102) is perpendicular to the screen 130 and the original Image 120 (provided on a projection medium such as LCD panel 110). Therefore, the light source 102 is collinear with the center of the projection medium and the screen, so the keystone distortion is at a minimum. Due to the vertical alignment of the light source 102, the LCD panel 110 and the screen 130, FIG. 1A can be understood as a top view or a side view of the projection system. The original image plane 122 is parallel to the screen no, and the projection axis 104 faces the center of the LCD panel. In this projection system, an original image is displayed on the LCD panel, and light from the light source 102 is projected on a video screen or plane 130 through the original image. The light source 102 is an illumination structure of the projector 100 and has a focal length 106. As will be understood by those skilled in the art, in the projection system shown in FIG. 1A, the original image 120 in the LCD panel 110 is projected on the screen 130 from the projector 100, and the original image 120 will be enlarged in size. But the details and proportions of the original image will be reproduced straight. Therefore, keystone distortion will not seriously detract from the viewer's appreciation of the projected image. It is easy to understand from FIG. 1A that once the projector 100 (ie, the light source 102 and the LCD panel 110) is rotated or repositioned so that the projection axis 104 is no longer perpendicular to the screen 130, the LCD panel 110 will no longer be parallel On the screen 13〇 and the original image flat 08168twf1.doc / 006 repair 1 ^ month 92 side 122. It becomes desirable to prevent or correct keystone distortion. The situation of an embodiment of the invention described above can be used to generate 'distorted or corrected images from the following images. The deformed or corrected images can be projected with distortion, and the keystone distortion will be From directly to this / by no stepping 捋 捋 Chōchan 4 :. Fig. 1B shows the image projection system 'projector 100 (still represented by the light source 102) in the embodiment of the present invention from the vertical projection and the original image plane 122. State shift.第 ⑺ 陶 可 理 __ 幕 130 This is a side view of the projection system, in which the projector 100 should be regarded as a horizontal translation or rotation of the horizontal axis of the light source, so that it must now be projected to the screen in the relevant direction. 130. The projection axis 104 still passes through the center of the upper plate, however it has been translated with the projector 100. The longitudinal angle formed by τ between the projection axis 104 and a straight line of the plane of the vertical screen 130 may be referred to as an elevation angle, and is represented here as 0. _ Similar to the piano, the elevation angle can introduce a horizontal angle into the projection system, which means that the projector 100 moves horizontally or rotates about a vertical axis. This angle is called the glance angle and is denoted here as α. Therefore, the elevation angle < 9 indicates the vertical offset of the projector from a position of the projection axis 104 perpendicular to the original image (and screen 130), and α indicates the horizontal offset. Figure 1B can therefore also be understood as the top view of the projection system after a sweep angle has been applied instead of an elevation angle. The elevation angle 0 in this case should be interpreted as the sweep angle α ° From the previous discussion, it will be understood that the keystone distortion may originate from the misalignment of the projection axis 104, the LCD panel 110 and the screen 130, as described in FIG. Like that. Therefore, in one or more of the following embodiments of the present invention, the original image 12 received from the light source is transformed before it is displayed on the LCD panel 110 at the date of 556440 correction 92 · 6 · 30 0 8168twf1.doc / 〇〇6 Distortion or distortion 'which remains perpendicular to the projection axis. In FIG. 1B, Image · 1 indicates the original image (for example, in the original image plane 122) that would appear if it was aligned on the screen 130 in parallel. As described in detail in the subsequent sections, Image-I provides a convenient starting point for generating a distorted image that is presented on an LCD panel and projected onto the screen with minimal, if any, keystone distortion. FIG. 1C illustrates the manner in which a rectangular original image on the LCD panel 110 appears on the screen 130 when the projector 100 is moved or rotated horizontally and vertically (that is, the elevation angle Θ and the scanning angle are greater than zero). Specifically, in FIG. 1C, instead of replacing the original image with an appropriately deformed image, the original image is projected and keystone distortion is not corrected. The projection axis 104 passes through the center of the original image and the LCD panel 110 (not shown in FIG. 1C). Screen image 140 appears vertically and horizontally distorted because projector 100 is not vertically aligned with screen 130. In Figure 1C and the embodiments of the invention discussed below, in describing how an original image can be adjusted to prevent keystone distortion, two three-dimensional coordinate systems are used for reference purposes. The first coordinate is represented by a lowercase letter (X, y, z), and the light source 102 of the projector 100 is used as the origin (that is, the light source is 0 point and has the coordinates (0, 0, 〇)). In this system, the X axis is horizontal to the light source, and the z axis forms a central projection axis 104 through the LCD panel and the original image. The LCD panel is parallel to the x-y plane, and the unit of measurement in the system may be a pixel pitch unit of the LCD panel. This can be called a projection or light source coordinate system. 16 08168twfl.doc / 006 Revised Date 92 · 6 · 30 The second coordinate system is represented by uppercase (χ, γ, ζ), and has an origin of 0. At the center of the original image, one will appear parallel to the video screen. Plane (for example, the original image plane 122 shown in FIGS. 1A-1B). The X axis of the system extends horizontally, the Y axis extends vertically and the Z axis is perpendicular to the original image plane 122. This coordinate system can be referred to as the Image-1 coordinate. In alternative embodiments of the present invention, different coordinate systems may be used without limiting the scope of the present invention or limiting the manner in which one of the images can be translated or changed. For example, in an alternative embodiment, a coordinate system origin may be placed at a corner of the original image so that all coordinates in the Image-1 coordinate system are included in a quadrant. In another alternative embodiment, the coordinate system may have an origin positioned in the LCD panel. Those skilled in the art will appreciate that datums in one coordinate system can be easily transformed to another coordinate system, and embodiments of the present invention therefore do not limit any particular coordinate system. It can be seen in FIGS. 1B-1C that the projection light beam from the projector 100 passes through the LCD panel 100 to the screen 130 and impinges on the screen unevenly with respect to the projection axis (ie, the z-axis). Due to the tilt and scan angles in FIG. 1C, the upper right corner of the screen image 140 expands and expands more than the other parts of the original image. Conversely, if the projector 100 is located at a position perpendicular to the screen 130 (such as in Fig. 1A), the screen image produced will ideally be symmetric about the projection axis. FIG. 1D illustrates distortion of a portion 140a of the screen image 140 from FIG. 1C. It is described in the figure 140A in the coordinate system (X, γ, ζ) of the original image plane. In addition to the original image coordinate system and the Z coordinate 08168twfl.doc / 006 modified date 92.6.30 axis, the projection axis (the 2 axis) of the projection system is also shown extending to the upper right part of the section 14 (^. The elevation angle 0 and the sweep angle α are described. Figures 1A-1D illustrate trapezoidal distortion that can be caused by displacement of the light source along, that is, about the horizontal axis, vertical axis, or both. As briefly described above, in one embodiment of the invention Keystone distortion can be mitigated by deforming the original image 'in this way to compensate for possible keystone distortion. Specifically, according to the angles 0 and α and according to the size of the original image or display device, rescaling, twisting , Translation, or other deformation of the original image, it is possible to achieve a tolerance for trapezoidal distortion caused by projecting an image at a non-orthogonal angle to the viewing screen. By displaying the deformed image in The LCD panel 110 has to make necessary offset adjustments before, so that the projection on the screen 130 closely matches the original image, especially the original image is very close to the scale. It can be targeted against the standard Other corrections, such as magnification, movement, and aesthetic factors, such as brightness, sharpness, contrast, etc. Specifically, the light intensity of individual elements (such as pixels) of an image can be corrected in order to increase the Uniformity or special effect. In one embodiment of the present invention, an original image can be deformed according to the tilt and sweep angle of the projection system, and the size of the original image can be adjusted as needed to fit the LCD panel 110, and Correct the original image to achieve projection without trapezoidal distortion. The effect of this deformation is like an enlarged version of the original image without trapezoidal distortion. Seen on the screen 130, the image shrinks with the LCD panel 110 or toward the light source 102 A perspective view of the image. FIGS. 6A-6B show a projection system according to the above-mentioned coordinate system according to an embodiment of the present invention. In this embodiment, the elevation angle Θ is not zero (for example, the light source 102 08168twf1. Doc / 006 correction date 92.6.30 has been rotated about the X axis), but the scan angle a is zero. Figure 6A is a side view of the projection system (ie, along the X- and X coordinate axes), and Figure 6B is the system A top view of the system (ie, looking down the y-axis). Screens 130 are not shown in Figures 6A-6B.

Image-1 124 represents the original image that can be received for projection, as it can appear in a plane parallel to the video screen (e.g., original image plane 122). A distorted image (hereinafter referred to as Image-2) is calculated from Image-i, and is provided on the LCD panel 110 for projection on the screen 130. The focal length 106 is the focal length of the light source 102. For easy reference, the focal length 106 is denoted as d, the center of the LCD panel is located at point a of the projection coordinate system, and has (X, y, Z) coordinates (0, 〇, d). The origin of the light source coordinate system (ie, the light source 102) is represented as point 0. In the lmage_; l coordinate system, the center of Image-1 is at point 0, and the (X, Y, Z) coordinates have (0, 0, 0). As shown in Figure 6B, the four corners of Image-1 are represented as points CO, Cl, C2, and C3, which are respectively located at the coordinates (W, H, 〇), (W, 〇), (-W, -H , 0) and (-W, H, 0). W and Η respectively represent half the width and half the height of the original image. Apparatuses and methods for generating an appropriately deformed image on an LCd board from a raw image and projecting it on the screen 130 are described in the following section. The term "original image" refers to an image received from an image source (such as Di Erfang, an image library, and a storage device) and will be projected on a screen. "Mageq 〃" refers to the original image in a plane parallel to the screen. You can use the Image-I Block I series described above. Image_2 〃 refers to the deformation of the original image, which can be explained. 〇8l68twf1.doc / 006 Revised date 92.6.30 is presented on an LCD panel, and is projected on the screen with minimal or no keystone distortion. Image-2 can also be called a distorted or displayed image, and can be described using this light source coordinate system (introduced above). An embodiment of the trapezoidal misalignment adjustment device can perform a sequence of various methods and processes to form a distorted image (such as lmage-2) from an original image (such as Image_l) for display on an LCD panel without significant The keystone is projected onto a plane. In this section, a suitable device and illustrative optional devices for performing one or more of these methods are described. The present invention is not limited to the structure described in this section, and other structures that can be changed or adjusted are also suitable. Fig. 2 is a block diagram of a device for generating a display image from an original image, in which the display image is provided on an LCD panel and is projected on a screen without noticeable keystone distortion. In FIG. 2, the device 200 includes a CPU interface 202, a memory interface 204, a digitizing device 206, and a generator 208. In one embodiment of the invention, the device 200 may be included in a projector or a projection system. In this embodiment, the CPU interface 202 is coupled to a processor that may be inside or outside the device 200. The CPU interface 202 communicates with the processor in order to coordinate memory access (e.g., access to a Gamma table). The processor may operate according to a sequence of instructions to facilitate the performance of one or more of the various methods of the invention described in the sections that follow. The CPU interface 202 includes a storage space composed of one or more registers. The memory interface 204 is connected to a memory (for example, SDRAM, S GRAM, 08168twf1.doc / 006, 92.6.30 ROM, disk), so as to store and retrieve images. The memory interface 204 accesses a memory representing other components of the device 200 shown in FIG. For example, the digitizing device 206 or the CPU interface 202 may instruct the memory interface to store image data (such as image data of a new original image), assuming image data at a prescribed storage location. That is, the generator 208 or the CPU interface 202 may instruct the memory interface to retrieve a specific amount of image data starting at a determined position in the memory. In addition, various parameters that may be used to obtain Image-2 from the original image may be stored in a storage managed by the storage interface 204. Specifically, the digitizing device 206 and / or the generator 208 may store or receive parameters from a memory interface for use in resizing or deforming the image. The memory accessed by the memory interface 204 may be inside or outside the device 200. In one embodiment, the memory interface 204 ensures that all memory requests are serviced quickly (e.g., at a timed interval) so that image processing and deformation are not delayed. The image stored in the memory accessed through the memory interface 204 may include an original image (such as Image-1) and a distorted image (such as image-2) to be displayed on an LCD panel or other display device. ). As described above, 'if an original image is directly displayed by a projector, it may be affected by the trapezoidal distortion. However, producing a properly deformed image 'from this original image constitutes a projection with almost no keystone distortion from the LCD panel or other suitable device. Alternatively, one or more intermediate images between the original image and the display image obtained from the original image may be stored in the memory. For example, 556440 modified date 92.6.30 08168twf1.doc / 006 One or more digitizing devices 206, generators 208, or other modules as described below can be rotated, translated, contracted, expanded, or deformed in one or more operations. Image in order to transform the original image into a suitable image for projection without feeling keystone distortion. Without departing from the scope of the present invention, the functions of one or more components of the device 200 can be combined or distributed in a manner different from the embodiments described in the following subsections. Examples of Digitizing Devices Figures 3A-3B depict an embodiment of a digitizing device 206 in an embodiment of the invention. In this embodiment, the original image is received and stored in a memory. Before storage, the original image can be adjusted in some way (such as reducing, enlarging, rotating, or other adjustments to prevent keystone distortion or introduce other effects). Intuitively, the digitizing device 206 includes an image receiver 302, a reducer 304, a regulator 306, a keystone module 308, and a controller 310. In the illustrated embodiment, the controller 310 is coupled to an image receiver 302; a reducer 304, an adjuster 306, a keystone module 308, and one or more image sources of the original image. In addition, the controller 310 is coupled to the CPU interface 202. The image receiver 302 is also coupled to the one or more image sources to receive raw image data. A regulator 306 and a keystone module 308 are coupled to the memory connection 204. Intuitively, raw images from one or more sources, such as storage media (disk or tape), processors; one or more analog-to-digital converters, etc., are received at the image receiver 302. Can receive 22 556440 from one or more sources at a time Correction date 92 · 6 · 30 08168twfl.doc / 006 Receive one line of the original image, or for a color image 'One pixel from a different source at a time The map receives color signal data for an image. Therefore, the image receiver 302 may be constituted by multiplexing data from multiple sources or receiving a single data stream from a single source. In the illustrated embodiment, the controller 310 interfaces with the source of the original image to synchronize the reception of the image data. In an alternative embodiment, this task may be performed by another module or component of the projection device. The reducer 304 is structured to reduce the size of the original image in one or more dimensions according to one or more scales. It may be applied based on several factors to reduce a given original image (for example, for each dimension, line, or other indiscriminately different scale of the image). These factors are the size and / or source of the original image, the size of the display device from which the modified display image is projected (eg, LCD panel 110), the memory space in which the original image is stored, the elevation angle ^ 0 or Sweep angle α and so on. In one embodiment of the invention, the reduction ratio is a number not greater than one. As a result, the image stored in the memory in this embodiment is not larger than the original image. The reducer 304 may combine one or more storage buffers (e.g., line buffers) or other storage devices to temporarily store portions (e.g., lines, pixels) of the reduced image. These registers may be part of the memory of the CPU interface 202 or its coupled CPU, or the registers may be part of a repository coupled to the memory interface 204, or the registers may include inherent to the digital device 206 One or more modules. The number and size of the buffers incorporated in the embodiment of the present invention may depend on the speed of storage access, the rate at which image data is received in the digitizing device 206, the original picture 2 08168twf1.doc / 006 modified date 92 · The predicted size of the 6.3 image, the rate at which the image is provided on the display device, and so on. In one embodiment of the present invention, 'Each line buffer is large enough to store one piece of data for computer-generated tube sharpness (eg, 640, 800, 1, 024, or 1,280 pixels per line) image Line, and has good color coverage (such as 16 or 32 bits per pixel). In an alternative embodiment of the invention, the structure (e.g., quantity, size) of the line buffer may be programmable to accept original images of various sizes, colors, and sharpness. The reducer 304 may also include components (e.g., multiplexers, demultiplexers) that cooperate with the line buffer to manage the flow of data through the line buffer. The adjuster 306 receives a reduced image from the reducer 304 (e.g., line-by-line from a buffer used by the reducer) for storage in a memory. Additionally, the adjuster 306 may be configured to deform or twist one or more portions of the image received from the reducer 304. Specifically, in the illustrated embodiment, the keystone module 308 generates a scale or other coefficient by which a portion (e.g., one line) of the image is distorted to prevent keystone distortion. Different scales can be applied to different parts of the image. Via the memory interface 204, the modified or distorted image data is stored from the adjuster 306 in the memory. The regulator 306 may employ a second set of storage (eg, line) buffers and related components to segment image data in the buffer and / or recombine image data from the buffer. In an alternative embodiment of the invention, the adjustment function of the adjuster 306 to prevent keystone distortion may be combined with the reducer 304, and even further implemented in different parts of the device 200 (e.g., implemented in the generator 208). In another embodiment of the present invention, 08168twf1.doc / 006 of the digitizing device 206 may be combined with 92.6 · 30 of other components. Prior to storing the image, the keystone module 308 stores or retrieves the appropriate parameters from the memory for use in deforming or distorting the image. This parameter may include the necessary scale to be applied, or a scale that can be calculated by the keystone module, in which the image is reduced or distorted in the digitizer 206. The different sets of parameters described in the subsequent sections can be used for different embodiments of the invention. These parameters can be used to deform an original image (such as Image-I) to compensate for keystone distortion, or to determine how to deform the image 'will form an appropriate display image (such as Image-2). As described above, in one alternative embodiment of the present invention, one or more operations for preventing keystone distortion may be performed in different components of the digitizing device 206, or in a module other than the digitizing device 206. Therefore, in a case where, for example, a module having similar functions can be included in the generator 208, the trapezoidal distortion module 308 can be omitted from such an embodiment. FIG. 3B illustrates the manner in which the digitizing device 206 can reduce an original image (eg, Image-1) in one embodiment of the present invention. As described above, 'the digitized device 2 0 6 receives the intuitive _ ^ dimensional original image 3 5 0. In this example, the horizontal scale of the original image is stored in a register (variable or other data structure) and is called original-X, which is related to reference number 352 in Figure 3B. The vertical scale of the original image 350 is called Original-Y, and is related to reference numeral 354. Intuitively, Original-χ and Original-Y are expressed in units of the Image-1 coordinate system. When the original image 350 is received and processed by the digitizing device 206 (eg 08168twf1.doc / 006 revision date 92.6 · 30 progressive processing), it can be stored or intended to be stored in a memory accessed through the memory interface 204 Zoomed out image 360. The horizontal and vertical scales of the reduced image 360 are stored as Write_X362 and Write-Y364, respectively, indicating the scale of the storage space written therein. The starting memory locations for storing reduced images 360 can be stored as Start-Write-X 366 and Start-Write-Y 368. The ratio of Write-X 362 to original_X 352 and

The ratio of Write-Y 364 to Original-Y 354 is called Reduce-X and Reduce-Y ratio, respectively. These ratios are the reduction ratios described above. FIG. 3C illustrates the operation of the regulator 306 of the digitizing device 206 that adjusts or distorts the reduced image according to the scale provided by the keystone module 308 to prevent keystone. In Figure 3C, the reduced image 360 is distorted line by line to produce a distorted image 370. In one embodiment of the present invention, the deformed image 370 can be used as a display image (eg, Image-2), presented on an LCD panel, and projected onto a video screen. In another embodiment, the adjusted image 370 may be rescaled (e.g., enlarged) to form a suitable display image. The manner in which the image is distorted can be determined by a portion of the display device that will render Image-2. For example, the method for preventing trapezoidal distortion described in the following section shows how to obtain an appropriate effective area of Image-2 from Image-1. Therefore, in a method for preventing keystone distortion described below, an original image is received with the digitizing device 206, and one of the images stored in the memory, Start-Write_X and Start-Write-Y, is read to start storing the image. starting point. Then as it is stored in the memory ', the original image is scaled down to Reduce-X on the horizontal scale and then scaled down to 08168twf1.doc / 006 on the vertical scale. If any of these ratios is equal to 1, the image is stored at its original size in the respective scale. If the image is to be transformed by the digitizer, the image can also be distorted on a progressive basis before being stored. In addition to the reduction and adjustment operations described above, the digitizing device 206 may perform another operation, such as various image filtering functions for an original image. For example, in one embodiment of the present invention described below, the brightness or light intensity of the original image is equalized to produce a projected image having a uniform or near-uniform intensity. The above-mentioned various registration and image data may be held by the CPU interface 202 (not shown in FIG. 2), may be held in a storage managed by the storage interface device 204, or may be a part of the digital device 206 or other parts of the device 200 Serving. Generator Embodiments Figures 4A-4B depict an embodiment of a generator 208 of the apparatus 200 in one embodiment of the invention. The function of the generator in this embodiment is to provide an appropriate display image (Image-2) on the LCD panel, CRT screen, etc., for projecting on a video screen or other plane in order to reconstruct an image without obvious keystone distortion The original image, specifically, the generator can be configured to scale, resize, or otherwise deform the image data in the memory (such as to compensate or prevent keystone distortion), and to transform the result to a specific size or 淸The clarity is forwarded to a prescribed display device. That is, the generator can be configured to simply retrieve and provide a stored image that has been deformed by a digitizer. 08168twfl.doc / 006 Modified date 92.6 · 3. However, in an alternative embodiment of the present invention, both the digitizing device 206 and the generator 208 can perform the deformation operation (for example, the elevation angle β and the scanning angle α are not zero). The generators depicted in Figures 4A-4B are configured to operate with the digitizer 206 described in Figures 3A-3C. Therefore, the generator shown is not configured to perform keystone correction because the function is performed by the digitizer. The generator 208 in FIG. 4A includes an image receiver 402, an interpolator 404, and a controller 406. The image receiver 400 may include one or more buffers (such as a line buffer) configured to receive and temporarily store image data received from the memory interface 204. The number and size of line buffers combined in an interpolator may depend on the speed of memory access, the rate at which image data is received in or from digitizer 206, and the prediction of the original image. Size, how image data is received (e.g. progressive, pixels), etc. The interpolator 404 is configured to receive an image from the memory (for example, a reduced image 360 of the first image or a deformed image 370 of the 3C image), and if necessary, used for translation or rescaling, and transmitted to A display device such as the LCD panel 110. The interpolator in one embodiment of the present invention adjusts the size of the retrieved image according to a prescribed ratio (described below). The controller 406 receives commands from the CPU interface 202 (shown in FIG. 2), and controls operations of the image receiver 402 and the interpolator 404. Fig. 4B illustrates the interpolation of the image data stored in the memory, such as the stored image 450, into a display image 460 (Image-2). When using the above-mentioned digitizing device 206, several variable or other data structures of 08168twf1.doc / 006 modified date 92.6.30 registers can be used to store the interpolation of the relevant stored memory data into the data to be projected An image. In Figure 4B, Start-Read-X456 and Start-Read-Y458 define a starting position in the memory from which the image data is extracted. The other registers store Read-X 452 and Read-Y 454, which indicate the dimensions of the storage area to be read. Further, Display-X 462 and 〇1 邛 1 ”-γ464 define the horizontal and vertical dimensions of the display device (ie, the portion of the display device used to display the image 460). The ratio and the ratio of Display-Y 454 and Read-Y 464 can be labeled as Enlarge-X and Enlarge-Y, respectively. These ratios therefore determine the size of the stored image 450 expanded or interpolated in order to produce a display image of a suitable size Degree. Intuitively, these two ratios have at least one 値. It can be seen later that the function of the generator 208 of FIG. 4A is to adjust the size of a stored image to fit a display device. During the interpolation process, Other image enhancement functions can also be performed, such as adjusting the sharpness, contrast, brightness, gamma correction, etc. of the displayed image. Those skilled in the art will understand that the functions performed by the digitizing device 206 and the generator 208 are complementary. Specifically That is, the modification of the stored image by the generator 208 to produce a display image that can be projected without trapezoidal distortion depends on the corresponding original modified by the digitizing device 206 This method, along with its function of changing the size and shape of the original image, produces the appropriate display image. Figure 19 shows a method using this section and the previous section of the generator 208 and digitizing device 206. The original image is transformed into a display image that can be projected with little, if any, keystone distortion. In the state 1900, 08168twf1. Doc / 006 Modified Date 92.6.30 Receives an original image with a digital device. This figure The image can be received as a complete set of data or can be part of each reception and processing (eg, progressive). If necessary, in state 1902, the digital device adjusts or rescales the image. For example, it can be reduced or Extract the scale of the original image in order to store the image in a specific storage area. The above scales can be applied, such as Reduce-X and Reduce-Y. The rescaling factor applied by the digitizer can be applied to the original image. Defined and stored before being received, or can be determined when receiving images. Intuitively, when less storage space is required, reducing the original image makes the The scale of the original image is maintained. In state 1904, the digitizer transforms the image in order to compensate for keystone distortion caused by a projection system angle (such as elevation angle 0 and / or sweep angle α). Intuitively, this Processing is performed on a line-by-line basis based on pre-stored parameters obtained from the projection system, describing how each line must be adjusted to offset the effects of keystone distortion. In addition, this parameter can be calculated in real time. The deformation of state 1904 can be Performed in order or combined with the recalibration of status 1902 fr. And 'as described in the following subsection' deformation of an image to compensate for or prevent keystone distortion can be performed only on the digitizer or generator Executed by one or the other, or by both modules. Moreover, in the case where the elevation angle and the scanning angle are not zero, respective deformation operations can be performed for each angle, and the operations can be combined again using the recalibration operation of the digital device or generator, that is, placed in the sequence. In the state of sadness 1906, the image was stored in the memory 08168twf1. Doc / 006 on a date-by-time basis, with a revision date of 92.6.30. The memory in which the images are stored can be managed by the memory interface 204 described above. In state 1908, the generator retrieves (e.g., progressively) the image data from the memory. However, as described below, in another embodiment of the present invention, the image is rotated by reading and compiling the stored image data in a column-by-column format for additional processing (for example, according to another The projection system is distorted). In state 1910, the generator rescales the image as needed for a specified display device (e.g., one or more LCD panels). Specifically, the usable or effective area of the display device may be defined using parameters stored in a memory or according to a parameter generated by operation. The generator can then resize (for example, enlarge) the image retrieved from the memory to use the largest possible area or a prescribed area of the display device. In state 1912, the deformed image is provided on the display device, and is projected on a screen in state 1914. Examples of EL Selection Digitizers and Transponders As described above, efforts to correct or avoid keystone distortion may be performed in either or both of the digitizer 206 and the generator 208. In addition, the keystone correction / avoidance function can be performed by different components in these modules (such as described in Figure 3A) or can be combined with other functions of a module or a module's components (such as reducing or enlarging an image) Together. Therefore, the optional structure of the apparatus 200 will now be described with reference to FIGS. 5A-5D. Those skilled in the art will readily understand the manner described in Figure 19 and the above method of operation that can be adjusted to 08168twfl.doc / 006 revision date 92 · 6 · 30 to suit these optional device configurations. The device 200a depicted in Figure 5A has a digitizing device 206a and a generator 208a, similar to the digitizing devices and generators of Figures 3A and 4A. As already described, the main function of the digitizer in this embodiment is to prevent keystone distortion. As understood by those skilled in the art, the order of the reduction and adjustment operations performed by the reducer 304 and the regulator 306 in the digitizing device 206a of Fig. 5A may be reversed in another alternative embodiment. FIG. 5B illustrates the device 200b, in which the functions of image reduction and keystone prevention of a digitizing device are combined. The reducer / regulator 505 of the digitizing device 206b in this embodiment performs the functions of both the reducer 304 and the regulator 306 of Fig. 5A. The reducer / regulator 505 may incorporate a set of buffers (e.g., line buffers) to store portions of an image when the image is processed and before it is stored in the memory by the memory interface 204. The device 200a illustrated in Fig. 5C is the case when it performs keystone correction in the generator 208c instead of the digitizing device 206c. In this embodiment, the digitizing device 206c still reduces an original image if necessary. When the reduced image is retrieved from the storage by the generator 208c, the image is enlarged and adjusted (e.g. distorted, deformed) in any order before being sent to the display device. The regulator 508 and the keystone module 510 are combined into a generator 208c for the purpose of preventing keystone distortion. These components can be constructed and operated in a manner similar to the corresponding components in the digitizer 206 of Fig. 3A. Fig. 5D shows a device 200d that integrates interpolation and keystone adjustment functions in the generator 208d. Specifically, the interpolator / regulator 512 executes 556440 〇8168twf1.doc / 006 Date of revision 92.6.30 A ^ image retrieved from the memory is expanded and expanded as necessary to prevent Two functions of keystone. A method to prevent the loss of the shape of the image-as described above, in one embodiment of the invention, before an original image received from an image source is provided on a display device such as an LCD panel, The original image is distorted, distorted or otherwise adjusted. Then, when the display image is projected, the projected image can be viewed without noticeable trapezoidal distortion. Figures 7A-7B show an effect of this method. Figure 7A depicts in solid lines the boundaries of an original image (such as Image-I) that may be received before any deformation or change. A display image 700a (for example, Image_2) displayed in a dotted line is an image obtained from the original image 700 and provided on the LCD panel 110 to be projected on one screen. Intuitively, the display image 70oa is the result of the talented woman needing to adjust the size of the original image and deform it appropriately. Obviously, the centers of the original image 700 and the display image 700a indicated by the points 702 and 702a, respectively, are consistent with those in Figs. 7A and 7B. One method for generating Image_2 from Image-1 can include

The determination of the correct shape of Image-2 is to compensate for any trapezoidal distortion that might otherwise be caused by the elevation angle 0 and / or the sweep angle ^. As described below, ′ can be determined based on the geometric relationship between Image-1 and Image-2. The shape of Image-2 can be referred to as its effective area because it defines an area of a display device in which the image can be provided. The original image 700 is provided in the projection system of Figs. 6A-6B. 33 08168twfl.doc / 006 Modified date 92 · 6 · 30 on the LCD panel 110 and projected on the screen 130 to generate the 7B image to The solid line depicts the projected original image 750. One can easily perceive the resulting keystone distortion. However, the projected display image 75 (shown by the dashed line) is the result of the projected display image 700a using the same projection system, and shows the ability to reduce or eliminate keystone distortion according to an embodiment of the present invention. Figure 6A. In one embodiment of the present invention, the display image 700a derived from the original image 700 can be displayed as follows. In this embodiment, the elevation angle 6> is not zero, and the scanning angle a is equal to 0. This specialty The skilled person will recognize a method for preventing keystone distortion. A sweep angle or elevation angle can be modified to prevent keystone distortion for different angles. Another embodiment of the present invention is directed to a projection system in which both angles are non-zero. Below The described embodiments of the present invention are used to offset the effects of one or both of the elevation angle and the sweep angle. In the presently described embodiments, the original image is received and appears to be presented on the LCD panel without distortion or adjustment. From the position inside the other LCD panels, the image is then rotated around an axis running through the center of the LCD panel parallel to the X axis at an elevation angle of 0. The 0-degree rotation of the image places it parallel to the screen Then move the image along the Z axis, keeping its center on the z axis, away from the LCD panel and toward the screen or plane until just one edge of the image is on the plane of the LCD panel Until the coincidence. This image can be represented as Image_l as the first step to get Image-2 (the deformed image is provided and projected with almost no keystone distortion). At this position (for example, parallel to the screen 130), Image- The relationship between I and the plane of the LCD panel reconstructs the elevation angle 0 ', the center of which is collinear with the projection axis of the light source 102. Fig. 1b shows the position of image_ 1 08168twfl.doc / 006, date of correction 92.6.30, bottom edge of Image-1 This position meets the LCD panel, forming an elevation angle of 0 between them. However, it should be noted that in an alternative embodiment of the present invention, the LCD panel can overlap Image-I and vice versa. By capturing the geometric perspective of Image-I Projection, Image-2 (that is, the display image presented on the LCD panel) can then be generated on the LCD panel as if Image-1 was retracted toward the light source 102. As can be seen in Figures 7A-7B, Image-2 ruler in this embodiment Depends on the elevation angle q, and will not be greater than Image-1. Therefore, in one embodiment of the present invention, a series of calculations are performed on an original image (such as Image-1) in order to obtain an image that can be projected without trapezoidal distortion. A display image (Image-2). Specifically, for each part (eg, point, pixel) on the LCD panel that can be provided and projected, the corresponding part of Image-1 is marked. The corresponding part The features (such as color, light intensity, contrast) can then be applied to the LCD panel. In one embodiment of the present invention, it is assumed that before obtaining Image-2, further translations in the coordinate system of the light source (ie, xyz) or Relocating its geometric center adds compensation to an intermediate image (eg Image-I). Intuitively, compensation can be expressed as (r, 5, λ). Figures 8A and 8B illustrate the effect of applying a horizontal compensation (i.e., parallel to the X axis) to move Image-I left or right relative to its original direction on the image projected on screen 130. Recall that the center of Image-I is aligned with the projection axis in its original direction. Figures 8C and 8D show the effect of applying a vertical offset (i.e., parallel to the y-axis) to slide Image-1 up or down before generating Image-2. Similarly, Image-1 can be compensated along the Z axis, as shown in Figures 8E and 8F, so that 08168twfl.doc / 006 amends 92.6.30 to enlarge or reduce Image-2. Fig. 8E shows a zoom-out effect of panning Image-1 further away from the LCD panel, and Fig. 8F shows an enlargement effect of panning Image-I toward the LCD panel. However, if too much compensation is specified so that a portion of Image-2 appears outside the displayable area of the LCD panel, the portion can be cropped rather than displayed or projected. For example, the area enclosed by 804a, 806a, 808a, and 810a in Figure 8A will not be displayed or projected because it extends beyond the displayable portion of the LCD panel. Similarly, the portion of Image-2 extending below the displayable area of the LCD panel is not projected. If image-I is translated or shifted along the X-, y-, or z-axis before or in combination with the deformation of an image, those skilled in the art will understand the methods described below for creating an appropriate Image-2 calculation method. In addition, FIG. 8G shows a manner in which the size of the projected Image-2 can be increased due to upward displacement, which may not be obvious in FIG. 8C. The different sizes and positions of Image-2 before and after being moved can be easily compared. Similarly, a smaller Image-2 can be projected by moving Image-1 down. However, when compensation is not injected into the calculation, the geometric centers of Image-1 and Image-2 coincide on the same beam from light source 102 (shown in Figures 7A-7B). Beneficially, this alignment runs through the projected image, so little adjustment by the operator or user is required, which ensures accurate reproduction of the original image. Furthermore, an edge of Image-1 is aligned with the plane of the LCD panel before Image-2 is obtained, and the size of the generated image is maximized by using as many display areas of the LCD panel as possible. Of course, as the elevation angle 0 (or scan angle α) increases, the display image obtained from the original image will require 08168twf1.doc / 006 correction date 92.6.30 to shrink in size. In the following discussion of a method for obtaining an appropriate Image-2 from an Image-1, a position within a coordinate system (such as a light source or an Image-1 coordinate system) can be represented as a 没有 without z or Z dimensions . Those skilled in the art will understand that in these embodiments of the present invention, the coordinates of all points in the Image-1 plane or Image-2 plane will have a constant Z or z 値, respectively. Specifically, all points in the LCD panel have d 値 (focal length of the light source 102) in the z-dimension, and all points in Image-1 have 0 値 in the z-dimension. It should be understood in the following discussion that Image_1 is formed by reorienting the original image so as to appear in a plane parallel to the video screen. Further, Image-2 is the deformation of Image-1 or the original image to fit within the appropriately shaped display area of the LCD panel. The shaping of image-2 can be obtained from the geometric or spatial relationship between Image-1 and Image-2 and is constructed visually in order to substantially compensate for any keystone distortion that may be introduced into the projected image. The tick relationship between IMAGE-1 and IMAGE-2 is described in a subsection. The geometric relationship existing in a projection system using an embodiment of the present invention is described, so that the Image-2 generated from Image_1 in the subsequent subsection Various methods can be better understood. As described below, these relationships can be used to locate each part of Image-2 (such as pixels) corresponding to the part of the original image (ie, lmage_1}. Features (such as color, intensity) of the corresponding part can be added To the LCD panel in order to produce an effective modification of the original image that can be projected with little, if any, keystone distortion. 08168twf1.doc / 006 Revision Date 92.6.30 In this embodiment of the present invention, Image-1 And the center of Image-2 is aligned with the z-axis (projection axis), so that the operator of the projection system will not need to make constant adjustments according to the projected image. In addition, it is provided on the LCD panel (or other display Device) Image-2 is as large as possible; this is achieved by aligning one edge of Image-1 with the LCD panel before calculating Image-2. Size (eg dimension, shape) of Image-2 Changes with elevation angle 0 and / or sweep angle α. An intuitive projection system in which an embodiment of the present invention can be applied will now be described in order to demonstrate the geometric relationship that affects the conclusion of Image-2. 9A-9B shown in the figure In this system, the light source 102 (not shown in Figures 9A-9B) of the projector 100 is placed at point 0 (〇, 〇, 〇) in the coordinate system of the light source. The orientation of the projector 100 causes the projection The axis 104 (ie, 2 axes) forms an elevation angle 6 »relative to a straight line perpendicular to the screen 130 (also not shown in Figs. 9A-9B); the scanning angle α is zero. Therefore, Fig. 9A is a projection system Side view and Figure 9B is a top view of the projection system. Those skilled in the art will easily understand how the method currently described can be modified to work in a projection system with a swept angle and no elevation angle, or two of them In a system where the angles are not zero, the LCD panel 110 is placed at a position d from the light source (for example, the focal length of the light source 102) so that its center, that is, point A in Figs. 9A-9B in the coordinate system of the light source Is in the coordinates (0, 0, d). The center of Image-1 is represented as point 0, the coordinates (0, 0, 0) in the Image-1 coordinate system. Image-1 in Figure 9B The angles are represented as points C0-C3. As mentioned above, Image-I is generated by rotating and translating the original image from the LCD panel Therefore, 08168twf1.doc / 006 between the LCD panel 110 and Image_1 is revised at 92.6.30 and the present angle is 0. The LCD panel 11 in Figure 9 A-9B and Image-1 have the same scale (ie 2Wx2H) It is not necessary for other embodiments of the present invention. Intuitively, the widths (ie, actual sizes) of the units in the two coordinate systems are completely the same, so that the units of the LCD panel 110 and Image-1 are easy to compare.

The point P of Image_1 is an intuitive point with coordinates (X, Y, 0) in the original image. Point P 'is the corresponding point in the LCD panel 110 (i.e., on the same light beam from the light source). The position of the point P 'can be displayed as (X, y, d) in the coordinate system of the light source. Point A is therefore the projection of point P 'on the z-axis, while point B represents the projection of point P on the z-axis. In Fig. 9A, y represents the length of the line segment (A, P ') projected on the y-z plane, and X represents the length of the line segment (A, P') projected on the x-z plane. Similarly, Y represents the length of the line segment (0, P) on the Y-Z plane, and X represents the length of the line segment (0, P) on the X-Z plane. The point B can be defined as a light source coordinate system with coordinates (0, 〇, d + Yz), where Yz represents the length of the line segment (A, B). Specifically, the trigonometric method requires sin (< 9) = Yz / (H + Y), so Yz = (H + Y) * sin (< 9). Similarly, the length of the line segment (P, B) in the y-z plane can be expressed as Yy. The mathematical expression is cos (0) = Yy / Y, and Yy = Y * cos ((9). As can be seen in Figure 9A, when Image-1 is positioned (for example, parallel to the video screen, its center is at On the projection axis and one edge coincides with the plane of the LCD panel 110), the LCD panel can extend beyond the edge of Image-1, or vice versa. Specifically, the connection between the LCD panel 110 and Image-1 in FIG. 9A Expressed as J. The length of the line segment (A, J) can be described as H ', and since cos (0) = H' / H, then H '= H * cos (0). Therefore, the LCD panel 110 extends 556440 to modify Date 92.6.30 08168twfl.doc / 006 The distance beyond the edge of Image-1 is Η · (H * C0S (0)). Several other mathematical relationships can be obtained from the projection system shown in Figures 9A-9B And equations will be used below to generate 1mage_2 from Mage · 1. First of all, we can see that the triangles ΛΟΑΡ 'and Λ〇ΒΡ are geometrically similar. Therefore, Yy represents the orthogonal distance from the LCD panel to the point, and Α represents the line segment (ο , Α) and ◦ B represents the length of the line segment (ο, Β), it can be seen that: x: X = y: Yy = 〇A: oB. Because the length of the line segment (ο, Α) is equal to d, and The length of the line segment (ο, B) is equal to (d + Yz). This proportional relationship can be rewritten as: ⑴ x: X = d: (d + Yz) = y: (Y * cos (0)) Figure 9A Note that Yz is equal to the length of the line segment (A, B), which can be divided into (A, 0) and (0, B). Moreover, the length of the line segment (A, 0) = (H * sin (0)), and The length of the line segment (〇, B) = (Y * sin (< 9)). Therefore,

Yz = Η * sin (0) + Y * sin ((9) replaces this Yz 値 on the left side of equation (1), yielding: X = [(d + (H + Y) * sin (0) * χ] / d (2) However, in order to be able to determine the coordinate of an element from the light source coordinate system (ie, (X, y, z) coordinate system), the image · 1 coordinate system (ie, (x, y, z) coordinate 4) is determined. 08168twf1. Doc / 006 To correct the coordinates of an element (for example, a pixel) in the 92.6.30 date system, you must eliminate Y 値 in equation (2). Substitute the above Yz 値 to the right of equation (1) and see d. (d + Η * sin (0) + Υ * Sin (0)) = y: (Y cos (0)) so that (3) (4) γ_ (6 / + // * sin (^)) * yd * cos (^)-^ * sin (^) and ^ * 7 * cos (^) " + * sin (^) + 7 * sin (^)) The function Ry (y) represents the scaling factor. It is used to map the y-coordinate of a pixel in Image-2 (such as pixel P 'in Figure 9A) to a corresponding part or the Y-coordinate of a pixel in Image-1 (such as pixel P in Figure 9A) Specifically, Ry (y) can assist in expressing or expressing the relationship between the positioning or position of a line in Image-1 and the positioning of the corresponding line in Image-2. Function Ry (y) is defined as follows:

Ry {y) = ά ^ Η ^ ύη {θ) i / * cos (^)-j * sin (^) Therefore, equation (3) can be simply expressed as Y = Ry (y) * y, and can be represented by Rewrite so that Y is a function of y that gives 値 d, Η, and 0: Y (y) -Ry (y) * y (5) Another function specified as Rx (y) is used to express the scale Factor for 556440 correction date 92 · 6 · 30 08168twfl.doc / 006 a given y-coordinate, used to map the X-coordinate of a pixel (eg pixel P ') in Image_2 to one in Image-1 The X-coordinate of the corresponding part or pixel (for example, pixel P). Specifically, Rx (y) can assist in expressing or expressing the width of a line in Image-1, or the position of an element within the line, and the relationship between the corresponding line or element of Image-2. Rx (y) can be defined as follows:

Rx (y) = Ry (y) * cos (e) d * cos (^)-3; * sin (6 ^) It is obvious to those skilled in the art that the given 値 and the given elevation angle for d and H Θ, for a particular y 値, the Rx (y) is constant (for example, within a specific pixel line in Image-2), and the corresponding X 値 is proportional to X (X, y). Rhenium for Rx and / or Ry can be stored in a table or in other data structures. Eliminating the middle term in the above equation (1) shows X: X = y ·· (γ cos (6 >)); therefore X = (Y * cos (0) * X) / y. Substituting Y 値 in equation (5), we get X = (Ry (y) * cos (0) * X), where X is now represented by X and y. And, because Rx (y) = (Ry (y) * cos (0)), X = Rx (y) * x. This equation can be rewritten as a function of X and y for a given d, Η, and 6 »値: 42 556440 correction date 92.6.30 08168twfl.doc / 006 X (x, y) = Rx (y) * x (6) That is, X can be represented by X and Y instead of x and y. Specifically, the left side of equation (1) indicates X: X = d: (d + Yz). Because Yz = (H * sin (0) + Y * sin (0)), we can see + sin (^) + Y * sin (^)) * x)

Ji —- d which can be re-expressed as: φ χ (χ? 7) = W + (// + r) * sin_ * x, d can now introduce the function Rx (Y), indicating that it can be applied to Image-2 -The X 値 of a specific pixel, in order to determine the corresponding X coordinate of the pixel in Image-1 according to a Y 値. Rx (Y) can be defined as follows:

Rx (Y) = (d + (H + Y) * sin (0)) / d (7) and therefore X (x, Y) = Rx (Y) * x (8) where d, Η, and 0 are constants value. Rx (Y) should be considered as a linear function of Υ, however, it is not always possible to use Υ 値 in Equation (8) to be an integer for the use of 方程 in Equation (8), thus complicating the calculation slightly. In short, Rx (Y) helps to calculate the Υ coordinate of a pixel in Image-1, which corresponds to an image 4 in Image-2 with a given y coordinate. Correction date 92.6.30 08168twfl.doc / 〇 〇6 prime. Similarly, Rx (y) and Rx (Y) help to calculate the x_coordinate of the image_i pixel based on the y 広 L of the ^,] pixel or the y_coordinate of the Image-1 pixel, respectively. A method of calculating a scaling factor such as Rx (y) or Rx (Y) by adding or subtracting an increasing adjustment (eg, not multiplication) is described below. Can be used to map an element (eg a pixel) of Image-2 to

The equations of the corresponding elements in Image-1 are renumbered in the description of the following subsections in the embodiment of the present invention for easy reference: 物) = 八, butterfly / c, (n) (one (12) Y (y) = Ry (y) * y (13) χ (X, y) = Rx (y) * x (14) Rx (Y) = (d + (H + Y) * sin (Θ)) / ά (15) and X (X, Y) = Rx (γ) * χ · (16) From these equations, according to the point P ′ in Image-2, the coordinates of a point P in Image-1 (X, Υ) (shown in Figures 9A-9B). The characteristics of some parts of Image-2 in the LCD panel 110, such as color tone, brightness, light intensity, etc., can be copied from the corresponding parts in Image-I to be faithful 08168twf1.doc / 006 The original image was reproduced with a revision date of 92.6.30. Of course, the characteristics of Image-2 can be further adjusted or modified (for example, exceeding or replacing features inherited from Image-1) in order to Apply a specific effect or state. As briefly stated above, in one embodiment of the present invention, although the coordinates of a pixel in Image-2 can be expressed as an integer (in the light source coordinates), but calculated from the above equation The coordinates of the corresponding Image & I & coordinates (in the Image_l coordinate system) may not have an integer 値. When the calculated Image-1 part is not aligned with a pixel or other separate elements are to be interpolated from adjacent pixels ，, A method for determining this feature is applied to an Image-2 pixel. In one embodiment of the present invention, all adjacent pixels (for example, a maximum 値 of eight pixels) are used for interpolation. In an alternative embodiment You can use any number of pixels-not limited to adjacent pixels. In another alternative embodiment of the invention, an averaging method can be used to smooth the characteristics of nearby pixels. Determine the effectiveness and precision of IMAGE-2 After obtaining Image-I from the original image, Image-2 can be formed in one of the methods described in the following subsection. However, in one embodiment of the present invention, it is determined that the available image is in tons before Image-2 is obtained from Image-I. Or effective area. The area of the display device marked in this process can represent the shape of the Image-2. Specifically, the shape of the defined range can be: when an image from Image-1 is used According to charging, the image can be projected without detecting keystone distortion. Intuitively, the useful part of the 1 ^ 〇 that is not occupied by lmage_2 can be filled with a background color or another pattern. 08168twf1. Doc / 006 Correction Date 92.6.30 Some factors that can affect the size and scale of the effective area of Image-2 include: elevation angle 0, scan angle α, scale of the original image (such as image-1), any compensation, applied to Image-1 ( (Above) expansion or contraction, focal length of the projection light source, etc. In one method of determining the effective area of an Image-2 image, the contour of the image is first calculated based on the number of lines in the image and the length of each line (for example, the length of each line measured by the number of pixels). Several parameters can be used in the following calculations to determine the effective area of Image-2. For example, the y-scale of the first valid or available line of the original image (ie, image _; [) that can be displayed as part of Image-2 (eg, the top line of the display image displayed on the LCD panel)不 Not marked by Star-Position-y. Similarly, End Position-y is the last line to be displayed, and Dimension-y is the total number of valid lines that can be displayed. These parameters can be expressed concisely as SPy, EPy, and Dy, respectively. Note that the last symbol (ie, lowercase letters) in these representations indicates where the applicable reference coordinate system-the light source coordinate system. Other parameters relate to the rows within the effective area of the Image-2 or LCD panel. Therefore, Star-Position-x (y) indicates X 値 of the first (e.g., leftmost) available or effective pixel in line number y. End- Position-x (y) indicates the last pixel in line number y, and Dimension-x (y) indicates the number of pixels in line y. These parameters can be expressed succinctly as SPx (y), EPx (y), and Dx (y). In summary, the parameters Star-Position_y (SPy), End-Position Y (EPy), Star-Position-x (y) ( SPx (y)), and EndPosition-x (y)

(EPx (y)) defines the effective or usable area of the panel 08168twfl.doc / 006 for revision image 92.6.30 for the Image-2 LCD in the embodiment of the present invention. Although Image-2 in one embodiment of the present invention can be moved into the LCD panel to display different portions of the image ', portions of Image-1 mapped to an area outside this area cannot be displayed. Similarly parameters can be introduced for Image-1. Therefore, Star-Position-y (SPy) and End- Position-Y (EPy) mark the first (eg, top) and last (eg, bottom) lines in Image-1, while star-Position-X (SPX) And End- Position_X (EPX) represent the first and last positions in a row of Image-1. SPX and EPX can be constants 値 for each row in Image-1, where Image-1 is rectangular on the outer row. However, in another embodiment of the present invention, where Image-1 is not rectangular or symmetrical, the start and end positions of a line in Image-1 can be expressed as SPX (Y) and EPX (Y), respectively. A method of obtaining a chirp associated with one or more of these parameters will now be described. For example, in the embodiment of the invention described in Figures 9A-9B, SPY = H and EPY = -H. And because these 値 correspond to SPy and EPy in the coordinate system of the light source, equation (13) can be re-expressed as: Y (SPy) = Ry (SPy) * SPy-Η and Υ (EPy) = Ry (EPy ) * EPy di-Η By solving the equations for the parameters SPy and EPy by using 値 of Ry (y) from equation (π), we see that 556440 has a correction date of 92.6.3〇 (21) (22) 08168twf1. Doc / 006 6 / * // * cos (^) ά + 2Η ^ ύη (θ) and EPy = (-H) * cos (0). Then, because Dy = SPy -EPy:

Dy = 2 // * cos (^) * (^ + // * sin (^)) d + 2H ^ sm (0) (23) And in Figure 9A-9B, SPX = -W and EPX = W. Therefore, it can be seen from equation (14):

X (SPx (y) 5 y) = Ry (y) * SPx (y) = -W

And X (EPx (y), y) = Rx (y) * EPx (y) = W Solve the equations for the parameters SPx (y) and Epx (y) according to equation (12), and get: SPx (y) = (-dW / k) + (tan (0) * W * y / k) (24) and EPx (y) (d * W / k) _ (tan (0) * W * y / k) (25 ) Where k = d + H * sin (0). Therefore, it is obvious that the Epx (y) =-SPx (y) shows the symmetrical characteristics for the rectangular original image. And because Dx (y) = 08168twf1.doc / 006, the revision date is 92.6.30 EPx (y)-SPx (y), we can see that Dx (y) = 2 * Epx (y), that is,

Dx (y) = (2 * d * W / k) (2 * tan (0) * y * W / k) · (26) Further, it can be seen from equation (26) that Z \ Dx (y), Image-2 The width difference (for example, the number of pixels) of one line from the next line can be expressed as AOxb) = Dx (y)-Dx (yl), that is, △ Dx (y) = -2 * tan ((9) * W / k. ( 27) For easier positioning, representation, or display, 値 obtained by any of the above equations can be rounded or rounded to an integer 値. The parameters SPy, EPy, Dy, SPx (y), Epx (y), and Dx (y) are therefore Defines the effective area of Image_2 on the LCD panel, as described in Figure 7A. These parameters can be stored in the projection system or a related memory, or can be calculated as needed for each received original image. These parameters It can be changed, for example, when the elevation angle 0 or the scan angle α is adjusted. The speed of the 7A image is out of the range of the points in Image-1? Corresponds to the point P 'in Image-2. For example,' in Figures 9A-9B In the description, a point 704 in image_i can be described by coordinates (SPX, SPY, 0) or coordinates (_w, H, 0). For point 704, Image-2 in Image-2 corresponds to point 704a in the light source coordinates. Department has Coordinates (SPx (SPy)), SPy, d). From the previous equations, one or more considerations can be achieved. Specifically, equations (24) and (25) show that the SPx (y) and Epx (y) are linearly changed with respect to 556440 08168twf1.doc / 006 of 92.6 · 30; in other words, when Image-1 (original When the image is rectangular, the sides of Image-2 are straight. And the slopes of these edges are opposite signs, so that the effective area of Image-2 is a symmetrical trapezoid. This may be different for non-rectangular images. Fig. 20 is a diagram showing a method for marking or determining an effective area of a display device or an effective area of an area in which an Image-2 display device can be provided. In state 2000, an original image is received with the scale Origin_X x Original_Y, which corresponds to 2 * Wx2 * H in Figures 9A-9B. In state 2002, the angle of the projection system (eg, 0 and / or the focal length of the light source (ie, d) is retrieved or determined. In state 2004, the first (SPy) and last line (EPy) positions of lmage_2 are calculated. In one embodiment of the present invention, these 値 are determined by applying the above-mentioned equations (21) and (22). In addition, the total number of rows (Dy) can be determined from the difference between the first and last ends of the equation or from equation (23 ) To determine that its y 値 can be stored. In state 2006, calculate the SPy (y) and Epx (y) 针对 for one or more rows of Image-2, or each row. Known from state 2004 Image-2's y-coordinate, and can be brought into equations (24) and (25) to arrive at the necessary 値. It can also be done by taking the difference between SPx (y) and Epx (y) or by applying Equation (26) calculates the width for a specific y 値, that is, the number of positions (eg, pixels) in each line (Dx (y)). In an alternative embodiment, the successive lines in Image-2 The width can be determined by accumulating the increasing factors derived from equation (27). 50 08168twf1. Doc / Ο06 Revision date 92.6.30 In the status 2008, the label The parameter set describing the effective area of Image_2 can be stored in the memory. For example, the parameters can be saved for use when another image of the same or a similar scale is received. Moreover, if Image-I is Translation (for example, through image compensation as described above), a new effective area can be determined by calculating and applying adjustments that must be performed on the parameter set in order to complete the compensation. IMAGE-2 pull from IMAGE · 1 The parameters described in the previous subsections of the two methods (such as SPy, EPy, Dy, SPx (y), Epx (y), and Dx (y)) provide a way to enclose the valid or available area, where Image_l can be shifted so that Form image_2. In one embodiment of the present invention, each part of Image-1 to be mapped to a part (for example, a pixel) of Image-2 can be labeled immediately. In other words, the correspondence in Image-2 can be calculated Each effective pixel of a pixel (or group of pixels) in Image · 1. In the embodiment of the present invention, the above equation (11) is calculated for each (x, y) coordinate in the effective area of the LCD panel )-(14), so as to mark a corresponding (x, y) coordinate in 1mage · 1. The related characteristics (such as color, brightness, contrast) of the pixels or pixel groups of Image-1 can be used for rendering Mage-2 pixels. As already described, the image_2 coordinate has a z-dimension of d (the focal length of the projection light source), and the image-i coordinate has a constant Z-dimension of zero. Intuitively, the position of a part of the Image-1 corresponding to one pixel in (x, y) in Image-2 can be expressed in the Image · 1 coordinate system as (X + 5 X, Y + 5 Y ). In the embodiment of the presently described 556440 of the present invention, the modified date of 92.6.30 08168twf1.doc / 006, these coordinates can be targeted using the given θ, d and Η of Η by applying equations (11) to (14) A point (X, y) within the effective area of image-2 is calculated. Specifically, 値 for Ry (y) and Rx (y) can be calculated for a given y 値. Y can then be calculated from Ry (y) and y, and X is calculated using Rx (y) and each X 値 associated with that given y 値. In an alternative embodiment of the invention, a slightly different method is applied to locate an Image-1 pixel at coordinates (x, y) corresponding to an Image-2 pixel at coordinates 0, y). In this alternative method, γ can be calculated as before (eg, using Ry (y) and the given y 値), after which rx can be calculated for each successive X 値 using equations (15) and (16) (y) and x (x, y). However, both methods may require efficient computational resources in order to enable the necessary calculations in an instant manner. Moreover, several other parameters or features as previously described can be used to describe how an original image is stored by the digitized device portion of a device and / or how it is retrieved by a corresponding generator portion. For example, it can be recalled that in one embodiment of the present invention, when an original image is stored in a memory, Reduce-X and Reduce-Y represent levels for adjusting (eg reducing) the size of an original image And vertical scaling factors. When the original image is received from the image source, Reduce-X and Reduce-Y can be calculated by a processor associated with the projection device. Moreover, the storage area in which the original image is stored can be described by Start_Write_X, Start_Write_Y, and Write_X and Write_Y.

Similarly, in the embodiment of the present invention, 'Enlarge_x and Enlarge_Y means to adjust the original image before providing the original image on one or more LCD panels. 52.556440 Revised date 92.6.30 08168twfl.doc / 006 ) A horizontal or vertical scaling factor that stores the dimensions of the original image. The area of the memory from which this stored image is retrieved can be described by the parameters Start_Write_X, Start_Write Y, Read_X, and Read Y. The storage area marked by these parameters may or may not correspond to the same storage area where the image was originally stored (for example, the area is marked by Star * t_Wdte_X, etc.). However, this calculation requires storing and retrieving an image, which may be difficult to combine with the calculations required to transform Image-1 to create Image-2. Specifically, the calculations related to the basic parameter groups SPy, Dy, SPx (y), Dx (y), Y (y), and x (y) are often used for the image Deformation. Therefore, whenever the scale of a stored, retrieved and deformed original image is adjusted, this parameter set may need to be recalculated. Moreover, in order to resize the image continuously or separately and deform the image, additional hardware may be required. For example, an image may require a set of line buffers for scaling (such as reduction or expansion), and a deformation of the image may require another set of line buffers. In one embodiment of the present invention, a set of parameters (e.g., SPy, Dy, SPx (y), Dx (y), Y (y), And X (y)) are stored in memory for use by a processor associated with the projection system. Intuitively, these and / or other parameters can be recalculated when Η, W elevation angle 0, or 値 of the scan angle α are changed. To save memory, the parameters can be stored in the area of the frame memory, which corresponds to the non-displayable area or part of the LCD panel outside the effective area of Image-2. In addition, 59 556440 amendment date 92.6.30 08168twf1.doc / 006 This parameter can be stored in other areas accessible to the processor ', such as in a memory accessed through the memory interface 204 of the device 200 described in FIG. 2. In another embodiment of the present invention, a memory having high coercivity (for example, a ROM) may be used. The burden of fast calculation and application of these parameters by a processor in this embodiment can be reduced by storing a pre-calculated parameter set in the memory. The stored parameter set may contain a large range of 値 for Η, W, 0, and / or α. This parameter set includes Spy, Dy, SPx (y), Dx (y), Y (y), and χ (Υ), or includes Spy, Dy, SPx (y), Dx (y), Y (y) This parameter group of, and X (Y) may be referred to as a first parameter group. The alternative method for obtaining Image-2 from Image-I described in the following subsection uses additional parameter groups, and can compare the performance or advantages of one method (or parameter group) with another method (or parameter group) . Figure 21 illustrates a method using the above parameter set to generate Image-2 within a predetermined effective area of a display device (such as an LCD panel). As will be apparent to those skilled in the art, the operations performed in this method can be rearranged in various orders. In state 2100, an original image is received from an image source. In state 2102, the image is resized as necessary for storage in memory. In state 2104, the images are stored visually in the memory in a progressive format. In state 2106, the image is retrieved from the memory (e.g. because it is about to be projected). In state 2108, the retrieved image which can now be called image-1 08168twfl.doc / 006 Revision date 92.6 · 30 Adjust the size according to the size of the display device. In state 2110, the effective area corresponding to ImaSe-2 is calculated or retrieved from the memory. For example, if the dimensions of the original image match the dimensions of the previous image, the parameters for an appropriate effective area may have been stored. The method described above for marking an effective area can be performed. In state 2112, by paying attention to its y-coordinate, selecting the first line (for example, the top row) of the effective area of Image-2 can be called as "乂" above. Then in state 2114, the above equation (Π ) And (12) calculate 値 for Ry (y) and Rx (y). In state 2116, calculate Y (y) (for example, using equation (13)), and can be expressed as (Y + 5 Y) to assist in locating the pixels of Image-1 corresponding to the pixels in the current row of Image-2. In state 2118, the first pixel in row y of Image-2 (for example, SP (y )). Then, in state 2120, (X, y) can be obtained by using equation (14) or similar calculations. This 値 of X can be expressed as (X + 3 X), so it is obtained that Image-I corresponds to The coordinates of (X, y) (X + 5 X, Y + 5 Y) in Image-2. The Z-coordinate for Image-1 is zero and the z-coordinate for Image-2 is d. In the state In 2122, one or more characteristics of Image-I at or closest to the coordinates (X + 5 X, Y + 5 Y) are copied and used for the current Image-2 pixels. For example, image-i pixels The color or intensity can be copied and applied. Intuitively, if (X + δ X, Y + (5 Y) coordinates do not closely match the coordinates of a single pixel in Image-1, the characteristics of multiple nearby pixels can be copied, Do smoothing, averaging, or other combinations, and use lmage_2 08168twfl.doc / 006 to modify the date 92.6.30 pixels. In state 2124, determine whether the current pixel is the last pixel in the current row of Image-2 (for example, Epx ( y)), if not, the method shown returns to state 2118, and the next pixel is selected (eg, by incrementing or decrementing 値 of X). If it is the last pixel in row y, the method enters state 2126. In state 2126 To determine if the last line of Image-2 ends exactly (eg EPy). If not, the method shown returns status 2112 and selects the next line (eg by incrementing or decrementing yy). Otherwise, complete Image-2 It is completely provided, and is projected on a video screen in state 2128, without significant keystone distortion. An alternative method of obtaining IMAGE-2 from IMAGE · 1 In an alternative embodiment of the invention, Computational complexity method to locate a portion of haged corresponding to a pixel in Image-2. This method strives to approximate the curves of Ry (y) and Y in equations (11) and (13). Now the method will be explained Derivation and simplification, start to apply equation (I5) to SPY and EPY, and start and end lines in Image-I (with 値 Η and -H, respectively):

Rx (SPY) = Rx (H) = 1 + [2 * Η * sin (θ) / ά] and Rx (EPY) = Rx (-H) = 1,

The 値 of Rx (Y) changes linearly with Y, which can be expressed as (5Rx (Y) The incremental change in rx (y) can be expressed as: 08168twfl.doc / 006 Modification date 92.6.30 SRx (Y) = Rx (Y + AY)-Rx (Y) = sin (^) * Δ7 / J (28) Therefore, once Rx (Y) is calculated for the first line of Image_l, such as SPY (ie Η) or EPY (ie-), pass Simply add or subtract (sin (0) * △ Y / d) to calculate subsequent 値 without repeating the calculation of equation (15) for each Y 値. This will simplify the determination of continuous X 値, And by adding or subtracting the multiplication and division of equation (15) to reduce the burden on the processor. By noting that the contour of the effective area of Image-2 for a rectangular original image is a symmetrical trapezoid, you can The calculation involved in equation (28) is approximated. Therefore, from the first line (ie, SPY) to the last line (ie, EPY), the difference in the y scale between successive lines in Image_2 is constant. The constant difference caused by the change is expressed as 6 Rx (y), so it can be calculated: 术 (29)

Dy Also, it is known that Rx (EPy) = Rx (EPY), because the bottom edge of the effective area of Image-2 coincides with the bottom line of Image-1 (as shown in Figure 9A). Also, the above shows that Rx (EPY) = Rx (-H) = 1; therefore, Rx (EPY) = 1. Then, starting from this 値, Rx (y) for each y 値 before EPy can be calculated by continuously adding or subtracting δRx (y). A close approximation to equation (13) can be obtained which significantly reduces the computational intensity. First, the second-order quadratic equations close to the matching equations (Π) and (13) can be expressed as: 556440 08168twf1.doc / 00 6 Date of correction 92.6.30 = + (30) Note that ΔΓ〇;) = Γ〇 + Ι) -rcy), so from this quadratic equation: (31) (32) ΑΥ (γ) = 2 ^ β2 ^ γ ^ (βι + β2) and: Τ〇; + 1) = Γ〇;) + ΔΓ〇;) Also, estimate equation (31) for (y + l) and simplify it: AY (y + \) = AY (y) + 2 ^ 2 (33) Therefore, from Y and AY can be added to or subtracted from this constant to obtain ay for the next y 値. Equation (30) shows Y (0) = &, and Δ} Λ⑼ = < ^ + magic is obtained from equation (31). Note that y = 0 indicates the middle line of Image-2 described in the embodiment of the present invention. Subsequently, ^ for continuous positive 値 for y can be calculated by continuous addition, and ΔΓ for continuous negative 値 for y can be calculated by continuous subtraction. For example, Δί ^) = Δ} / (0) + (2 * Α), or △ eight 1bu (for + /? 2+ (2 * eight)) = (for +3 * /? 2), and △ r (-i 卜 (Α + 久 — (2 * /? 2)) = (A -Α). Moreover, from γ 値 for a given y, such as Y (0) = A, equation (32) shows It can be determined by the addition and subtraction of ΔΥ corresponding to a given y 値. 59 008168twf1.doc / 006 The correction date 92.6.30 is used for the adjacent ya ya. Therefore, 1) = 80) 4 〇) 1. + (Is + ^). And F (-i) = F⑼ + ΔΓ⑼ = / ?. -(A + /? 2). Therefore, by calculating or selecting the appropriate amp of A & A, calculating a point Y 値 in Image-1 from a point in 1mage-2 is simplified and requires less heavy calculation. In one embodiment of the present invention, using the special case where Y (SPy) = SPY = H, Y (EPy) = EPY = -H, and Y (0) = 0, calculate where Van, A from equation (30) And where appropriate 値. Bringing these specific 値 into equation (30) gives: B2 * (57 ^) 2 + B1 * (57 »+ B0 = // B2 ^ (EPy) 2 + B, ^ (EPy) + B0 = -H and Solving these equations with = 0 gives the appropriate &, AA 値 for this embodiment, which can be stored in the memory for use in the process of deforming an image. It can be according to (21)-(22 Each equation of) calculates SPy and EPy. Therefore, a table or other set of various possible trivial, long, and long-lived 値 can be generated and stored for use in the process of deriving images from an original image. Calculations γ The present method of 允许 allows the use of addition and subtraction numbers instead of more complex, serious time-consuming operations, and therefore can allow 彳 officials to use processors and / or other devices of low complexity. IE like continuous Y 的 can That is, using a known Y 値 and adding or subtracting an increase γΔγ, the continuous 値 for X can be determined in a similar way. Specifically, Δχ (X, Y) = X (x, Y)- X (X-1, Y) = Rx (Y) with 556440 correction date 92.6.30 08168twfl.doc / 006 and Δχ (X, Υ + ΔΥ) two Δχ (χ, Y) + 5Rx (Y), where 5Rx ( Y) can be calculated using formula (28), and Δγ can be calculated using formula (32). Similar calculations can also be used for x (x, y). For example, δχ (χ, ΕΡΥ) Rx (EPY) = Rx (-H ) = 1 (for example, Si from formula (15)), and Δχ (χ, ΕΡΥ + Δγ) = Δχ (χ5 ΕΡΥ) +5 Rx (Y) = (l + (sin (0) * Δγ / d)). Moreover, because Rx (y) is a scaling factor capable of representing the difference between consecutive 値 of X within a given row corresponding to Image-2, once the first X 値 is known, the equation ( 14) can be executed recursively as: X (x, y) = X (xl, y) + Rx (y) (34) X can be calculated by estimating x (SPx (y), y) for each row of y Such an initial 値. Therefore, Rx (y) in equation (34) is approximately ΔX (χ, y), where Rx (y) = X (x, y) X (x_l, y) = Δχ (χ, y). It can be expressed recursively as △ AX (χ, y) = △ AX (X, y + 1)-5 Rx (y) (35) or Rx (y) = Rx (y + 1)-5 Rx (y ) Where (5 Rx (y) can be approximated by equation (29). Equation (35) can be applied starting from the bottom line of Image_2, where Δχ (χ, EPy) = Rx (EPy). For example, for all y of y of Χ (× 5 y) can be calculated in advance at 60 08168twf1. Doc / 00 6 The correction date is 92.6.30 and stored in the memory. Then, during the operation of continuously accumulating Δ × (X, y) of the projection system, each -X (X, y). Therefore, in one embodiment of the present invention, instead of calculating each individual X and Y 値 for a given set of parameters, the difference between consecutive 和 and 値 is calculated. Specifically, in the implementation of this example, the parameters set for Image_2 include SPy, Dy, SPx (y), Ax (y), ΔΥ (γ), and ΔX (y) or Δχ (γ). This embodiment embodies at least three advantages. First, the deformation of the image can be performed simultaneously with the resizing (such as reducing or expanding). Therefore, the convenience required to satisfy two operations with only one set of line buffers is achieved. Second, even if the scale of the displayed image (such as Image-2) changes, it is no longer necessary to calculate the entire parameter set. Third, the space required to store these parameters is less than the space required to store previous parameter sets. Recall that the part of Image-1 corresponding to one position in Image-2 can be expressed as (X, Υ) + (δX, 5Υ). In the currently described alternative embodiment to which the present invention is applied, (χ, Υ) may be initially set to (SPX, SPY), which is equal to (-W, H), and (5X, c5 Y) may be initially set to (〇, 〇). For example, this combination is the position of the upper left pixel of Image-1 and corresponds to the upper left effective pixel of Image-2, which can be expressed as (SPx (SPy), SPy). The calculation of subsequent positions in Image-I in this embodiment may depend on the way the size is adjusted (such as shrinking or expanding). For example, if the horizontal and vertical scaling factors (such as Reduce-X, Enlarge-Y) in the digitizer and generator are equal to 1 (that is, the image is neither decimated nor enlarged), the following procedure can be applied. For the first frame of y (ie, SPy, the first line in Image-2) and the first pixel (gpsPx (y)) in line y, 556440 the date of revision 92.6.30 08168twfl.d〇c / 〇〇6

Χ and γ 値 can be calculated using the equations provided above, which may be known (i.e., SPX, SPY). The X 値 of the holding pixels in row y corresponding to Image-2 can be calculated by accumulating AX (y) to (Dx (y) -1) using SPX (ie, -W). After getting this first line in Image-2, the subsequent ¥ 値 corresponding to the subsequent lines in Image-2 (that is, after SPY * H) can be reached by accumulating the number of times AY (y) with SPY (Dy-1 ) While calculating. Each X 値 within each subsequent line Y is calculated in the manner just described. In this manner, Image-2 obtains ′ one line and one pixel at a time and labels each corresponding portion of Image-1 by accumulating ΔΥ and AX (y). However, if one or both of the horizontal and vertical scaling factors are not equal to 1, the scaling ratio must be incorporated into the calculation. Specifically, X 通过 is calculated for a given row by continuously accumulating the product of AX (y) and a horizontal scaling factor (such as Reduce-X or Enlarge-X) in SPX. A continuous Y 値 (eg, Y (y + 1)) is calculated by continuously accumulating the product of AY (y) and a vertical scaling factor (eg, Reduce-Y or Enlarge-Y) at SPY. If the scale of this Image-2 is modified (such as reduced or enlarged), the required parameters (such as SPx, Dy, SPx (y), Dx (y)) can be modified accordingly by one or several appropriate scaling factors. In the present embodiment of the present invention, the position of Image_1, which is calculated by adding ΔX and Δγ 値 and expressed as (χ + 5χ, Υ + (5 Υ)), may not exactly match the position of the lmage-1 pixel. You can determine the characteristics to be assigned to the corresponding Image-2 pixels (for example, at position (x, y)) by analyzing (eg, accumulating, weighting, averaging) the characteristics of the nearby Image-1 pixels. 30 08168twf1.doc / 〇〇6 In order to distinguish from the parameter settings applied in the previous subsection, 'The parameter group includes SPy, Dy, SPx (y), Dx (y), AY (y), and Δχ (Υ), May be referred to as a second parameter group. Another alternative embodiment of the present invention is particularly suitable for a projection system in which the image (eg, Image_2) displayed on a 1 (: 1) plate has few, if any, changes. The parameter groups used in this embodiment include SPy, Dy, SPx (y), Dx (y), Y '(y), and X' (y), and can be referred to as a third parameter group. In this embodiment Where X '(y) and Y' (y) are the multiplication of X (y) and Y (y) from the first parameter group (discussed in the previous subsection) by the X and y scale scaling factors, respectively Therefore, one advantage of this alternative embodiment of the present invention is that the functions incorporated in the device in this embodiment are further enhanced. For example, a common setting of the line buffer is sufficient and may not require A keystone module (such as keystone module 308 in Figure 3A) that is used to generate a corresponding scale for each line of the image. According to the number of scale ratios to be prepared (that is, by comparing the scale ratio with The combination of X and Y parameters may require auxiliary storage space for various exchanges of the parameter set. Therefore, the skilled person will understand that using any one of the first, second, or second parameter set, or using the One of the groups and / or the other parameter sets obtained by the above equations include compromise choices. One parameter set and related methods for obtaining Image-2 may be excellent in terms of hardware cost, complexity, or storage space. The other The parameter set or method for obtaining Image_2 may be excellent in efficiency, performance, or other criteria. Those skilled in the art will understand that a parameter set and method Selection over another parameter group and method may depend on the particular application or image to be projected. 556440 08168twfl.doc / 006 Modified 92.6.30 Figure 22 illustrates one of the inventions described in this subsection Method, in which Image-2 data (eg, color, light intensity) can be obtained from the Image-1 part with less computational burden than the method described in the previous subsection. In state 2200, one of the above methods may be used to determine Image- Effective area of 2. In the case where the scales of the images to be projected are exactly the same or similar, especially in those cases where those scales are known in advance, the effective area of Image-2 can be calculated before the original image is received, thus reducing the Calculations that must be performed on reception. In addition, an effective area can be calculated for multiple sets of original image scales. In state 2202, various parameters are stored for obtaining Image-2. Specifically, in the method shown, the storage parameters include ... Spy, Dy, SPx (y), Dx (y), AY (y), and AX (y). As described above in connection with equations (30)-(32), 値 for Y (y) and AY (y) can be generated using a quadratic equation. Therefore, in state 2202, the appropriate units for Fan, A, and A can be generated, retrieved (eg, from a table), or stored as needed. Other parameters (such as Rx (y), cJRx (y)) can also be calculated and / or stored in order to perform as many necessary calculations as possible in advance. In an alternative embodiment of the invention, in state 2202, one or more parameters may be combined with a resizing or rescaling factor to be used for an image. As mentioned above, this enables any resizing of a ® | image to be performed consistent with its deformation. In state 2204, the original image is received from an image source. The image can be temporarily stored before further processing of the original ft image. In state 2206, the image is resized as necessary, perhaps for its temporary storage before it is deformed or provided at 6f 08168twf1.doc / 006, or according to the dimensions of the display device. In state 2208, a row in the effective area of Image_2 is selected. For example, this process can begin with the top line (ie, SPy). However, in alternative embodiments of the invention, the process can begin with the bottom line (i.e. EPy) or other lines (e.g., where y = 0). In state 2210, the 値 of Y (y) is determined. If the necessary parameters are calculated and stored in advance (for example in state 2202), this may include simply retrieving the radon from memory. Note that Y (SPy) = H. It is possible to determine by adding or subtracting 値 of ΔΥ (Υ) that Y 値 for the subsequent rows in Image-2, 値 of AY (y) may have been stored in state 2202. In state 2212, a position (e.g., pixel) x in row y is selected. For example, the first position in a row may be SPx (y); in this method, therefore, the first position selected in the first row (for example, SPy) is SPx (SPy) ° In state 2214, determine X (x5 y). The first position in the first line may be X (SPx (SPy), SPy), which is equal to -W. The 値 of X for the first position in each row may be a parameter stored in state 2202, or may be calculated at runtime. X 値 for subsequent positioning in row y can be determined by adding or subtracting the constant 値 AX (y), which can also be one of the parameters stored in state 2202. In state 2216, one or more characteristics of a part of Image-1 are retrieved and added to the pixel positioned at coordinates (X, y). In state 2218, it is determined whether the last position in line y has been processed. For example, if x = Epx (y), the method of the present invention continues in the state 08168twf1.doc / 006 correction date 92 · 6 · 30 2220. Otherwise, the method shown returns to state 2212 and another location is selected. In state 2220, it is determined whether the last line in Image-2 has been processed. For example, if r = EPy, the method shown will continue with state 2222; otherwise, the method shown returns to state 2208 and another row is selected. In state 2222, the provision of Image-2 on the display device is completed, and the result can be projected. Keystone Correction for Elevation or Sweeping Angle In this section, various embodiments for preventing keystone distortion when one of the elevation angle 0 or the scanning angle α is present (for example, non-zero) are described. Embodiments of the present invention for preventing keystone distortion when these two angles are present are described in the following sections. The structure of a device for implementing an embodiment of the present invention may depend on the setting of parameters selected to produce an appropriate display image (e.g., Image-2). Three intuitive parameter groups were described in the previous section. Those skilled in the art will recognize that any device structure not previously described described in this section and subsequent sections can be easily obtained from the structures that exist in this section. The structure of the sampling device can be observed with reference to Figure 24D. Illustrative 'deformation of an original image to produce the display image may be performed in a suitable device digitizer or generator module. As previously described, a digitizing device module can resize (eg, reduce) an original image for storage, and a generator module can resize (eg, enlarge) a stored image for providing on a display device. Any of these modules can combine the deformation operation with the adjustment operation of 〇8l68twfl.doc / 006 to correct the size of 92.6.30, that is, two operations can be performed sequentially. In one embodiment of the present invention, the digitizing device module reduces an original image (for example, according to 1 ^ 〇11 ^ 64 and 1 ^ (11 ^ 心 丫) to fit a specified storage area (for example, through a memory interface). Memory accessed by the module). The digitizing device can then transform the reduced image in a separate operation using components similar to the resizing operation. In this embodiment described in Figures 3B-3C, the first Parameter groups (for example, Spy, Dy, SPx (y), Dx (y), Y (y), and X (y)) can be used for deformation. According to an available area and tilt of a display device (such as an LCD panel) Or scan the view to calculate the parameters in this parameter group. For example, by using parameters Y (y) and x (y) (and maybe using Rx (y) and Rx (x)), the characteristics of Image-1 are copied into Image -2 of the calculated effective area, one line of the original image is deformed at a time. The content of each line (for example, from position SPx (y) to its length Dx (y)) can then be placed in memory. In the present invention In one embodiment, a row from SPy to EPy (ie, where EPy = SPy + Dy) is processed consecutively In another embodiment, the rows of Image-2 are processed or obtained in a different order. After the original image is resized, deformed, and stored, the generator module may apply the rescaling factors it has (such as Reduce- X and Reduce-Y) to fit the image data into the displayable portion of the LCD panel. In an optional method and device, the sizing and deformation functions of the digital device module are combined. Specifically, As each line of the original image is received and resized (eg, reduced), it is simultaneously deformed using a parameter set including AX (y) and △ Y (y) to simplify processing. The image can follow 08168twfl. doc / 006 Amendment date 92 · 6 · 30 is stored in memory. Beneficially, a group of hardware components can perform these two functions in one operation, instead of double the hardware components used in sequence The size and deformation of the image are adjusted. When the image is retrieved from the memory to be provided on the display device, the generator module resizes (eg, expands) the image as usual. This method is described in FIG. Out of the original Combined extraction (ie, reduction) and deformation of images like 1000 to form a display image 1002, which can then be stored in memory or transferred to a generator module. The display image 1002 can have a A generator module can be rescaled to the same scale, or before providing the display image 1002. Those skilled in the art will understand that although the foregoing methods shown in Figures 3B-3C and 10 describe the entire figure The image is enlarged and / or distorted as a unit, but the image can actually be modified one section at a time (eg, rows). In another alternative method and apparatus, deformation of an image is performed at the generator module. In an embodiment of the present invention, the digitizing device module may perform a resize (eg, reduce) operation to fit an original image into a storage area. When the generator module receives the image (eg, retrieves the image from a memory) and adjusts the size (eg, enlargement) of the image, the first parameter set is used again if necessary according to the tilt or sweep angle. An image distorted within the displayable area of the LCD panel. Specifically, the retrieved image is first enlarged and then its characteristics are applied to the corresponding part of Image-2, whose Image-2 is provided at * SPy, Dy, SPx (y), and Dx (y) 08168twf1.doc / 006 in the LCD_ section defined by 92.6.30 on the amendment date. For example, each line is a position provided each time, from SPX⑺ to Epx (y) (where Epx⑺ = spx (y)) 'called state' from the first line of spy to the last line of Epy. It is not enough to provide image data _ display equipment _ part can _ arbitrary _ provided (such as a background color). In the method shown in Figure 11A, a reduced image 110 () is shown (can be built and stored by a number ___)

It is interpolated or enlarged to form an enlarged image 1102. For example, the scale of the enlarged image 1102 may depend on the display device (such as an LCD panel). In the second operation, the enlarged image 1102 is deformed or distorted to form a display image 1104. Since the deformation of the image is performed last in this embodiment of the present invention, the quality of a projected image that can be generated by this embodiment is higher than the image that is executed before the image is interpolated (eg, resized) The quality of the projected images produced by those embodiments of deformation. Specifically, when image distortion is performed before resizing, the resizing operation can magnify any loss of sharpness or the diagonal to zigzag caused by the deformation of the image. For example, when the original image is rectangular, the distorted pattern of the image will usually be a symmetrical trapezoidal shape with diagonally opposite edges. When the diagonally opposite edge is subsequently resized for display, the larger the image is enlarged, the more uneven or tortuous the edge becomes. In another alternative method and device, the sizing and deformation functions of the generator module are combined. Because the generator module in this embodiment is not configured to reduce or reduce an image, the product of Enlarge-) ^ aAX (y) and the product of Enlarge-Y and ΔΥ (γ) should not be less than 1. Since all the figures 08168twf1.doc / 006 date of revision 92.6.3 are completed in the digital device module, the digital device module in this embodiment may be required to further reduce the original image than in other cases. image. The method is depicted in Figure 11B. The reduced image 1120 that has been created and stored in memory by the digitizer module is enlarged and distorted to produce a display image 1104 in a combined operation. Those skilled in the art will understand that although the entire image is not immediately enlarged and / or distorted in FIGS. 11A-11B, the image can actually modify one part (eg, row) in turn. The dotted lines in Figs. 10 and 11B can indicate the outline of the displayable portion of the display device, and thus show the manner in which the image is displayed when the image is provided on the device. The ineffective area of the display device (for example, within the dotted area without the display image portion) can be filled with color signal data similar to the video screen, other environmental areas, or a predetermined color, such as gray or black. Those skilled in the art will understand that if the trapezoidal distortion prevention function of the present invention is stopped, the function of each digitizer module and the function of each generator module in this embodiment described above may be equivalent. That is, in each embodiment, the digitizing device module adjusts the size (eg, reduction) of an original image to be stored in a prescribed storage area, and the generator module can adjust the size of a stored image for a display device. Size (e.g. enlarged). For example, the scaling ratio applied by the digitizer module is not greater than 1, and the scaling ratio applied by the generator module is not less than 1. The foregoing embodiments of the present invention also show that the ability to perform deformation or distortion of an image (ie, to prevent keystone distortion) in one of the digitizer or generator modules is performed sequentially or with each module The revision date is 92.6.30 08168twf1. Doc / 006 The resize function is executed together. Keystone distortion for an elevation and top angle i Figure 1C depicts a projection system in which the projector is tilted about the X axis (for example, upward projection) and moved left and right about the Y axis (for example, from the perspective of the projector) Right projection). Therefore, both the elevation angle 0 and the overhead angle α exist (that is, not zero). In one embodiment of the present invention, when both angles are present, keystone distortion is prevented by first obtaining an intermediate image that compensates for keystone distortion from one angle (e.g., elevation angle 0). Therefore, the intermediate image is then redirected by rotating the intermediate image by 90 degrees, and an appropriate display image can be obtained from another angle (e.g., elevation angle) that compensates for trapezoidal distortion. In this embodiment, the intermediate image is oriented within the original image (ie, 2 W width x 2Η height), and the display image fits the size of 2Η width and 2W height because the image rotation is inserted. Fig. 23 shows a method for preventing or compensating keystone distortion when the elevation angle and the top angle are not zero according to the present embodiment of the present invention. In state 2300, an original image with a non-zero elevation angle and a bird's-eye angle is received from an image source. In state 2302, it is determined whether the effective area of the image is already known. This may include the calculation, retrieval and / or storage of the several parameters mentioned above, which can be used for the following deformation processing. In state 2304, if necessary, the original image is resized (eg, reduced) for the specified storage area. This resizing operation can be considered as applying a 90 degree rotation to the image before it is stored. In state 2306, the image is distorted so as to compensate for keystone distortion that would otherwise result from a first angle of 556440, such as 92 · 6 · 30 08168twfl.doc / 006, such as the elevation angle (9). As described above, the Deformation may include mapping the characteristics of the original image to corresponding portions of the displayed image within a defined effective area. In one embodiment of the present invention, the resizing and deformation operations of states 2304 and 2306 may be reversed or combined A. One way to combine these operations was described above, where the resize and deformation factor or ratio are combined. In state 2308, the image is then rotated 90 degrees. This rotation can be performed just before storage, or Images are stored in a memory and executed at the same time. For example, the storage interface unit can receive reduced and distorted image data from the digitizer module in a row. The memory interface thus ends providing each line to the generator module Delivered as a column. In state 2310, the generator module then deforms the rotated image in order to compensate for other angles ( For example, the trapezoidal distortion caused by the viewing angle α). In the state 2312, the generator module can adjust the size of the image according to the needs of the display device. In one embodiment of the present invention, the adjustment of the size and deformation of the states 2310 and 2312 can Turned upside down or combined. One method of combining these operations was described above, in which the deformation and factor or scaling adjustments are combined. If the display device provides images in a line-based image format, state 2314 Before the image is displayed, it can be rotated 90 degrees in the opposite direction to the front rotation. In an alternative embodiment, the display device itself is rotated 90 degrees to avoid the final rotation of the image by the generator module This alternative embodiment eliminates any additional cache or storage resources that may require image rotation in the generator. 08 of 08168twf1.doc / 006 Date of revision 92 · 6 · 30 In state 23 16 the resulting graph The image is projected. Figure 12 is a block diagram of a device 1200 to prevent keystone distortion when both elevation and top angles are present. Digitizer 1201 and Each of the generators 1250 is used to compensate for trapezoidal distortion that may be caused by one of these two angles. For example, the original image received by the image receiver 1202 on the digitizer 1201 is resized (eg, reduced) by a reducer. So as to fit a specified storage area. The adjuster 1206 then deforms the image according to parameters or proportions calculated or retrieved by the keystone distortion module 1208 to compensate for distortions that may be caused by the elevation angle Θ. The adjuster 1206 applies One line (for example, a straight line) of the reduced and deformed image data is sent to a storage interface unit 1220, which rotates the image 90 degrees by storing the data in a column order. The controller 1210 of the digital converter 1201 controls the digital conversion And the data flows into the storage interface unit 1220. The stored image is received by the generator 1250 in the image receiver 1232. The size of the image is then adjusted by the interpolator 1234, and the image is deformed by the adjuster 1206 in order to compensate or prevent keystone distortion that may be caused by the top angle α. The regulator 1206 deforms the image data based on the input from the keystone module 1238, which can use parameters retrieved from a memory or calculated as needed. The controller 1240 controls the flow of image data from the storage interface unit and through the generator 1250. In the device 1200, after the generator module resizes and deforms the image so as to compensate for the overhead angle α, the image can be rotated 90 degrees in the opposite direction of the front rotation direction, or the display device itself can be taken or positioned at One direction of rotation. 556440 〇8168twf1. Doc / 006 Revised date 92 · 6 · 3〇 Figure imD shows the misalignment of a surface through a device according to the embodiment of the present invention, _ work, _____ _ from the top, the shape is caused by the shape Lose A. In the 13th, the original __ size (such as reduction) and deformation to compensate the elevation angle 0. The 36th figure shows the # ring of the deformed image · 9 埃 旋 __1_ 雑 bird's eye view ^. The direction of rotation (such as clockwise or counterclockwise) can be changed according to the sign of α5. Figure UC further describes the deformation of the image in order to complement the top view angle and adjust the size (eg, enlargement) of the image for the selected display device. The table 13D does not show the opposite rotation of the image rotation in preparation for being provided on a display device. In an alternative embodiment of the invention designed to compensate for keystone distortion, when both elevation and top angles are present, all resizing of the image is performed before it is deformed. It is therefore possible to improve the image quality in this embodiment. A method for obtaining a display image according to this embodiment is shown in FIGS. 14A to 14F. In Fig. 14A, the original image 1400 is reduced in a digitizing device module, and in Fig. 14B, the original image 1400 is enlarged in a digitizing device module. Figure 14C illustrates subsequent deformation of the image to compensate for the longitudinal angle (e.g., elevation angle Θ). This deformation can of course be combined with the enlargement of the image. In Fig. 14D, the deformed image is rotated by 90 degrees to prepare for further deformation. This rotation may be performed by converting row-type data into a column format. The second stage of deformation that compensates for horizontal angles (e.g., scan angle α) is shown in Figure 14E. Figure 14F shows the rotation of the image back to its original direction, or by rearranging the image data from a row format into columns 556440 〇8168twf1.doc / 006 correction date 92.6.30 style, or by putting the image It is faithfully provided on a display device that has been rotated 90 degrees. Another alternative embodiment of the invention is particularly suitable for compensating the elevation angle and the scanning angle when the display device cannot be rotated 90 degrees. In this embodiment shown in Figs. 15A-15E, the image is rotated twice in the memory. First, in the digitizer module shown in Fig. 15A, the 'original image 1500 is reduced (e.g., Reduce-X and Reduce-Y scaling down). Subsequently, the reduced image is rotated 90 degrees (for example, according to the sign of the scan angle α) and scaled up (for example, according to the Enlarge-X and Enlarge_Y ratios), as shown in Fig. 15B. This rotation may be performed by reading out image data of a reduced image created by the digitizer module in a row format and supplying its image data in a column format to a generator module (for scaling up). The image is then deformed according to a horizontal angle (such as the scan angle α) as shown in FIG. 15C. The rescaling and deformation shown in Figures 15B to 15C can be combined. The distorted image is then rotated 90 degrees to its original orientation as shown in Figure 15D. As described in Figure 15E, the image can now be deformed to compensate for longitudinal angles (e.g., elevation angle 0). The resulting display image can then be provided on a display device in a conventional line manner. Preventing the trapezoidal misalignment in ih or thunder target images In one embodiment of the invention, the image may be required to fit a particular size of the display device or a portion of the display device. In other words, instead of deforming an image and keeping it as large as possible (such as a full-sized display image), you deform the image and reduce its size to match the display 08168twf1. Doc / 006 Correction Date 92 · 6 · A display image of a specified part or full size of the display device. The resulting projected image is smaller in size and / or positioned on a different part of the screen, but still free of keystone distortion. Therefore, this section describes a method for obtaining a display image to meet specific size or location requirements. The method described can be used by one or more devices that already exist. By way of example, one or more of the parameters included in the description in the previous section may be modified to appropriately respond to the desired repositioning or resizing of the display image. Figure 16A depicts a display device 1602 with an active (ready-to-use) area bounded by a dashed line. If no keystone prevention is done, or if the elevation angle 0 and the scanning angle α have zero angles, the display image will fit the contour of the display device. One or more methods of preventing keystone distortion described in the previous section were attempted to maintain the display of an image as large as possible in the usable area of the display device (e.g. Image-2). In this section, however, the display image is intentionally reduced in size and / or positioned off-center from the display device. In the embodiment of the present invention described in FIG. 16A, a limited portion of a display device having a scale of (W, + W ") width x (H + H") height defines the display device to present a display image Area. This section is represented by unit 1604. Similar to the method described above for obtaining a display image using as many areas of the display device as possible, a display image adapted to the marked portion of the display device can be obtained, provided and projected without significant trapezoidal distortion. The portion of the display device outside the outline where the display image is presented may be filled with a background color or may be ignored. In order to obtain a display image that fits the reduced area 08168twf1.doc / 006 Modification date 92.6.30 image, define and calculate an appropriate set of parameters. In FIG. 16A, the starting point or position of the reduced display image according to the Image-1 coordinate system can be expressed as (-W ", H '), where Z 値 is 0. Therefore, the illustrated keystone prevention is shown in FIG. In the method, a display image projected from a reduced area has a scale of (W, + W ") X (H, + H ,,), SPY = H, EPY = -H", SPX 2 -W "And EPX = W '. As described in the method for "full-size" display image of the present invention, the parameters SPy, EPy, SPx (y), and EPx (y) can be obtained from the Image-1 parameter. Therefore, this method is similar to the above-mentioned method for displaying images of 〃regular〃 size, except that the parameter set is customized to provide a scale of a sub-region of the reduced display image. Figure 16B shows the result of deforming an original image (for example, in a digitizing device module) to fit within a sub-portion of the area where the full-size display image can appear. Unit 1610 indicates the outline of the full-size deformed image for comparison purposes. Unit 1612 can be understood as the border of the display panel provided with the reduced display image, or as the border of the storage area where the reduced image is stored. . The portion of the display device in FIG. 16B or the full-size display image in which the image is compressed corresponds to the area defined as 1604 in FIG. 16A. Fig. 16B illustrates a way to obtain a smaller display image scale from an image that may be different from the overall deformed image. Therefore, four points (SPx (SPy), SPY), (EPx (SPy), SPy), (SPx (EPy), EPy), and (EPx (EPy), EPy) define the trapezoidal region, where the entire The rectangular original image forms a smaller, compensated display and projected image. 08168twfl.doc / 006 Modified date 92.6.30 Similar to the method previously described in the present invention, the deformation of an image to be displayed and projected in a smaller and / or off-center area can be performed in a The generating module is not executed in a digital device. Moreover, in the case where both the elevation angle 0 and the scanning angle α have non-zero angles, deformation and / or size adjustment may be performed in both. For example, if the deformation is performed in a digitizing device module, as described in Figs. 16A-16B, the original image and related parameters can be based on the storage area where the image is to be stored or the storage area from which the image is retrieved. Scale or modify or recalibrate. The image is then reduced and deformed according to a desired area of the display device in which the reduced display image will be presented. The distorted image can then be stored in a storage area designated by parameters such as SPy, Dy, SPx (y), and Dx (y). As described above, the storage area from which the deformation is subsequently read out (for example by a generator module) can be identified by parameters 31 & 1 ^ Read-X, Start-Read-Y, Read · X, and Read_Y. For example, this storage area may correspond to the effective area of a full-size display image. If the deformation is performed in a generator module, the image retrieved from the memory is first interpolated (eg, enlarged) as needed, and then deformed to fit a specified portion of the display device. In a specific alternative method of preventing keystone distortion of smaller and / or off-center images, deformation of the image for a specific area is performed in a generator module. The method is described in Figures 17A-17B and is well-suited for changing the size or position of a sub-region of the display device in which a display image will be provided (for example, for one image or from one image to another). situation. In this optional method, the number of images used for retrieval by the generator is 0168168twfl.doc / 006, date of revision 92.6.30 is stored in an area smaller than the storage area retrieved by the generator, but the area It is proportional to the display area of the display device. Specifically, after the image is reduced by the digitizing device (if necessary), it is stored in a memory starting from a position (Start-Wdte_X, Start-Wiite-Y), as described above in connection with another embodiment of the present invention. . The memory part storing this reduced image data has a scale of Write-X X Write-Y. The storage area of the image data evicted or retrieved by the generator module has a scale of Read-X x Read-Y, and a start-position (Start-Write-X, Start-Write-Y). In this method, The size of the storage area read by the generator is larger than the size of the storage area storing the reduced image. And illustrate the ratio (2 * W): Read-X is equal to the ratio (W '+ W ”): Wdte-X. This common ratio can be implemented as a horizontal generator recalibration ratio (ie, Enlarge_X). Similarly, this Scale (2 * H): Read—Y is equal to scale (H '+ H' '): Wdte_Y, this common ratio can be implemented as a vertical generator rescaling scale (ie Enlar * ge__Y). Rescaling at the generator After the operation, the image can be deformed in order to compensate for keystone distortion and fit the designated part of the display device. Specifically, the coordinates (Start_Write_X, Start_Write_Y) are mapped to the display part (-W '' in the display device, H ') starting position. Therefore, a fixed parameter set can be used to deform the image data received by the generator. The generated projection image is shown in Figure ΠB as shown in Unit Π12. The outline of the video screen is Expressed as 1710. Equalized image brightness 556440 Corrected date 92.6.30 08168twfl.doc / 006 In one embodiment of the present invention, the light intensity of the original image is adjusted to control the state of the image projected on a video screen. For example, you might want to guarantee A uniform brightness across the projected image. Even without some mechanism for controlling or equalizing the brightness, the brightness may be changed from line to line after the original image is resized and deformed before being displayed and projected. Figures 18A-18C describe the uneven illumination of a projected image that may occur if not corrected, and the effect of the projected image on equalizing its brightness. In Figure 18A, a display image from the original image Image 1802 is affected by keystone distortion and the light intensity does not change. Therefore, the resulting projection B [Image 1804 is affected by keystone distortion and the light intensity is uneven. Specifically, the top of the image is darker than the bottom, probably due to the display device (Eg LCD panel) The light received or possessed by the lower part of the image provided by j is stronger than the light intensity received or possessed by the image 1. For example, or a low level of a displayed image The part can be changed to the day tone. The upper part can be brightened to equalize the brightness of the projected image. However, the selection of any solution in one embodiment of the present invention is performed on a line-by-line basis. In order to most effectively offset the unevenness of illumination. Specifically, the lower the row of the display device, the more the light intensity should be reduced, and the higher the row, the more the light intensity should be increased. In one embodiment of the present invention In order to correct the uneven brightness by adjusting the original image line by line, it is proportional to its initial light intensity and / or final position on the display device. Therefore, the light intensity of each line is reduced or attenuated from top to bottom. The attenuation of the lower line of the original image is greater than the attenuation of the higher line. Specifically, equations (21) and (22) show how to calculate based on d, Η and Yang 80 08168twf1. Doc / 006 correction date 92.6.30 angle 0 Out SPy and EPY for one original image. The attenuation coefficient or ratio used for each line, from SPy to Epy (for example, from the top to the bottom of the image) can be expressed as: A (y) = Dx (SPy) / Dx (y) (41) It can be seen that A (y) in the top row (that is, SPy) is equal to 1, indicating the smallest amount of attenuation, and A (EPy) will produce the largest amount of attenuation. This equation is specified in terms of y because y is customized to equalize the brightness in an image where only the elevation angle Θ exists. Those skilled in the art will readily understand that this attenuation factor can be determined for an image in which only the top angle α exists. If equation (41) causes the brightness of an image to decrease too much (for example, in the case where the projected image is too dark), the brightness of the original image can be increased overall, or the light intensity generated by the light source of the projection device Can be added. For an original image in which both the elevation angle Θ and the top angle α exist, the attenuation of the image light intensity can be performed in two stages. Equation (41) can be applied to attenuate the image for elevation angle 6 », and the top angle can be obtained from SPx to Ερχ by applying X 値: A (x) -Dy (SPx) / Dy (x) (42) at The image can be rotated 90 degrees before applying equation (42). Then the image is turned back to its original orientation for display. For example, the brightness control of the projection device can be adjusted so that the brightness in the image has been balanced β 556440 08168twf1. Doc / 006 Corrected date 92.6.30 Later it affects the overall light intensity of the projected image. Fig. 24 is a flowchart illustrating an example of a method of equalizing the brightness of an image by attenuating its light intensity according to an embodiment of the present invention. This method is suitable for the case where both the elevation angle 0 and the overhead angle α exist. This illustrated method can be easily modified, as will be apparent to those skilled in the art, to fit a projection system where only one angle has a non-zero angle. In state 2400, the number of pixels in each line y (i.e., Dx (y)) of an image is calculated. This parameter can be calculated with another parameter marked above, such as during the calculation of the effective area of an Image-2. In state 2402, the designation is calculated for each row y to indicate its correlation with the longitudinal angle 0. Specifically, A (y) = (SPy) / Dx (y) 〇 Then in state 2404, the vertical subtraction factor is applied in each line of the image. Specifically, in each, from SPy to EPy, for x = SPx (y) to x = EPx (y), the brightness of each pixel p having coordinates (x, y) is adjusted. Specifically, P '(x, y) = P (X, y) * A (y). In state 2406, the image is rotated by 90 degrees in order to prepare for the second phase of attenuation to target the horizontal angle α. For example, the image can be rotated to compile each row into a column. The rotation direction of the image can be determined according to the sign of the angle α. To reflect the rotation of the image, each pixel p, (x, y) can be represented as P '(y, X) for the following calculations until the image is rotated back to its original orientation. Similarly, for example, the Dy (x) parameter should be interpreted based on the rotation of the image. 556440 08168twfl.doc / 006 Revision date 92.6.30 In state 2408, calculate the scale of each line x (ie Dy (x)) in the rotated image. With the calculation in state 2402, state 2408 may be performed continuously or in combination with another image operation (such as adjusting the size or deformation of the image according to the angle α). In state 2410, the attenuation factor A (χ) associated with the scan angle is calculated for each row \. Specifically, A (x) = Dy (SPx) / Dy (X). In state 2412, each corresponding attenuation factor A (x) is applied in a corresponding row of the image. Specifically, in each line X, from spx to Eρχ, for y = SPy (x) to y = EPy (x), the brightness of each pixel P having coordinates (y, χ) is adjusted. Specifically, P ,, (y, X) = P, (y, X) * Α〇〇. In state 2414, the image is then rotated 90 degrees, in the opposite direction to the previous rotation. Therefore, each pixel P〃 (y, X) generated from state 2412 can be represented as a pixel P〃 (x, y) because the image is in the original direction again. In state 2416, such as when the image is projected, brightness control or brightness adjustment may be performed. For example, although the brightness is substantially balanced, if the brightness of the image is judged to be too low or too high for aesthetic reasons, it is necessary to control and adjust the appropriate brightness. In the foregoing description, 値 for Dx (y), A (y) for each line y, or for each line X after rotation is calculated together. In an alternative method, ‘can target one line at a time. In other words, one or more states of Figure 24 can be executed for only one row at a time. For example, starting with SPy, Dx (SPy) can be calculated (state 2400), followed by A (SPy) (state 2402), and then A (SPy) can be applied to each pixel in only one row of SPy (state 556440). The correction date is 92.6.30 08168twfl.doc / 006 2404), and then the row SPy can be rotated (state 2404) and so on. The embodiments of the present invention described above have been introduced for the purpose of illustration and description. These examples are not intended to be exhaustive or to limit the invention to the form disclosed. Many modifications and changes will be apparent to those skilled in the art. Therefore, the above disclosure is not intended to limit the invention: The scope of the invention is defined by the appended claims.

Claims (1)

556440 Revised date 92.6.30 08168twf1.doc / 006 Patent application scope: 1. A method for preventing keystone distortion in a projected image, for projecting an image from a projection system without significant keystone distortion on a The video screen includes the following steps: receiving the image at the projection system; reducing the image according to a first scaling ratio; enlarging the image according to a second scaling ratio; according to the definition, the projection system and the Deforming the image at a first angle between the screens to produce a display image; providing the display image on a display device; and projecting a portion of the display image on the screen without significant keystone distortion on. 2. The method for preventing keystone distortion in a projected image as described in claim 1 of the scope of patent application, further comprising the step of storing the image after said reduction and before said expansion. 3. The method for preventing keystone distortion in a projected image as described in item 1 of the scope of patent application, wherein said distortion is performed in combination with said reduction. 4. The method for preventing keystone distortion in a projected image as described in item 1 of the scope of patent application, wherein said distortion is performed in combination with said enlargement. 5. The method for preventing keystone distortion in a projected image as described in item 1 of the scope of patent application, further comprising the step of rotating the image. 6. The method for preventing% 08168twfl.doc / 006 in the projected image as described in item 1 of the scope of patent application for correction of keystone distortion of 92.6.30, wherein the first scaling ratio is not greater than 1. 7. The method for preventing keystone distortion in a projected image as described in item 1 of the scope of the patent application, wherein the second scaling ratio is not less than 1. 8. The method for preventing keystone distortion in a projected image as described in item 1 of the scope of patent application, wherein said distortion includes: marking an available area of the display device in which the image will be presented; and calculating The first part of the image is so represented in a first part of the available area. 9. The method for preventing keystone distortion in a projected image as described in item 8 of the scope of patent application, wherein said marking includes the image applied to the display device and the image in a plane parallel to the display screen Display of the geometric relationship. 10. The method of preventing keystone distortion in a projected image as described in item 1 of the scope of patent application, a step of further compensating the image before said distortion. 11. The method for preventing keystone distortion in a projected image as described in item 1 of the scope of patent application, further comprising the following steps: deforming the image according to a second angle defined between the projection system and the screen. 12. A method for preventing keystone distortion in a projected image for generating an image for projection from a projection system without significant keystone distortion, wherein a projection axis of the projection system is not perpendicular to the visual axis The angle of the screen is calibrated. The method includes the following steps: Correction date 92.6 · 30 〇8l68twf1. Doc / 006 Receives an original image with a set of scales; maintains a display device related to the projection system and parallel to the vision A set of parameters of the geometric relationship between a plane of the screen; defining an available area of the display device in which a display of the original image can be provided; marking the original image for one or more parts of the available area A corresponding portion of the image; and providing features of the corresponding portion of the original image to produce a display image for projection on the video screen by the projection system; wherein the display image can be without significant trapezoidal distortion projection. 13. The method for preventing keystone distortion in a projected image as described in claim 12 of the scope of patent application, further comprising the step of applying a scale factor to modify the scale of the original image before said providing step. H. The method for preventing keystone distortion in a projected image as described in claim 12 of the scope of patent application, further comprising the step of compensating the original image before said labeling step. 15. The method for preventing keystone distortion in a projected image according to item 12 of the scope of patent application, wherein said limiting step includes the following steps: marking the first line of the display image; marking the display image The last line of the image; a first position is marked for each line of the display image, and a display of a corresponding portion of the rectangular image is provided at the first position; and a last is marked for each line of the display image Position, with this last position providing a display of the corresponding part of said rectangular image. 556440 Revision date 92.6.30 08168twfl.doc / 006 16. The method for preventing keystone distortion in a projected image as described in item 15 of the scope of patent application, further comprising the step of determining the number of lines of the displayed image. 17. The method for preventing keystone distortion in a projected image as described in claim 15 of the scope of patent application, further comprising the step of determining the number of positions in one or more lines of the display image. 18. The method for preventing keystone distortion in a projected image as described in item 12 of the scope of patent application, wherein said step of marking a corresponding portion of the original image for one or more portions of the available area includes The following steps: determine the coordinates of a position in the available area; and calculate one or more positions in the original image corresponding to said position in the available area. 19. The method for preventing keystone distortion in a projected image as described in claim 18, wherein the step of calculating the coordinates of one or more positions includes: calculating one of a horizontal and vertical scaling factor Or both so as to be used for said coordinates at a location in the available area. 20. The method for preventing keystone distortion in a projected image as described in item 18 of the scope of the patent application, further comprising the step of storing a set of parameters in order to promote the said one or more positions in the original image Calculation of coordinates. 21. The method for preventing keystone distortion in a projected image as described in item 12 of the scope of patent application, wherein said step of marking a corresponding portion of the original image for one or more portions of the available area includes The following steps 8g 〇8168twf1.doc / 006 Revised date 92.6.30 Mark the first position in the first line of the original image; mark the next position in the first line by accumulating the horizontal increment factor ; And a position in the next line in the original image by accumulating a vertical increment factor. 22. The method for preventing keystone distortion in a projected image as described in item 21 of the scope of the patent application, wherein one or more of said horizontal increment factor and said vertical increment factor are included to modify the original image ~ Scaling factors for scale. 23 · —A method for preventing keystone distortion in a projected image, for transforming an input image to form an output image projected from a projection system on a screen, where the input image is Deform to compensate for keystone distortion, the method includes the following steps: determining a longitudinal angle between the projection system and the screen normal; determining a horizontal angle between the projection system and the screen normal; receiving the input Image; if the longitudinal angle is greater than or less than zero, transform the input image to correct keystone distortion that may be caused by the longitudinal angle; and if the horizontal angle is greater than or less than zero, transform the input image for correction Keystone distortion that may be caused by this horizontal angle. 24. The method for preventing keystone distortion in a projected image as described in item 23 of the scope of patent application, 556440 correction date 92.6.30 08168twf1.doc / 006, further comprising the step of adjusting the size of the input image. 25. A device for preventing keystone distortion in a projected image, for projecting an image on a screen surface with minimal keystone distortion, including: a first storage for storing data received from an image source A complete original image; a deformation module for deforming the original image according to an angle formed between a projection axis and a straight line perpendicular to the screen to form a display image; a second storage For storing a set of parameters that promote deformation of the original image; a display device for displaying the display image; and a light source for projecting the display image on the screen along the projection axis . 26. The device for preventing keystone distortion in a projected image as described in item 25 of the scope of the patent application, further comprising a plurality of rescaling modules for modifying the size of the original image. 27. The device for preventing keystone distortion in a projected image as described in claim 26, wherein the deformation module includes a first rescaling module. 28. The device for preventing keystone distortion in a projected image as described in item 25 of the scope of patent application, wherein said parameter group contains one or more parameters describing a region of the display device in which the display image is displayed parameter. 29. A device for preventing keystone distortion in a projected image as described in item 25 of the scope of the patent application, which is a 00908168twf1.doc / 006 correction date 92.6.30, wherein the parameter group contains one or more parameters, and For facilitating the marking of a portion of the original image to be displayed within a portion of the display device. 30. A projection system for preventing keystone distortion in a projected image, for projecting an image on a screen with minimal keystone distortion, including: a digitizer to receive the image from an image source The received image has a size; multiple resizing modules are used to modify the size of the image; a trapezoidal distortion module is used to deform a part of the image so that the compensation may come from projecting the image Keystone distortion to generate a display image; a display device to display the display image; a generator to forward the display image to the display device; a storage device to store a group Parameters, the set of parameters promoting one or more deformations of said portion of the image, and resizing of the image; and a light source for projecting the display image from the display device on the screen . 31. The projection system for preventing keystone distortion in a projected image as described in item 30 of the scope of patent application, wherein the keystone module is based on an angle formed between a projection axis of the light source and a line perpendicular to the screen To distort the image. 32. The projection system for preventing keystone distortion in a projected image as described in item 30 of the scope of patent application, wherein the digitizer includes the keystone 08168twf1.doc / 006 correction date 92.6.30 true module. 33. The projection system for preventing keystone distortion in a projected image as described in claim 30, wherein the generator includes the keystone distortion module. 34. The projection system for preventing keystone distortion in a projected image as described in item 30 of the scope of patent application, further comprising a second keystone distortion module. 35. The projection system for preventing keystone distortion in a projected image as described in item 30 of the scope of patent application, further comprising an attenuator for attenuating a portion of the brightness of the image. 36. A device for preventing keystone distortion in a projected image for deforming an input image to compensate for keystone distortion, including: a projector for projecting a display image on a screen to form a A projection image, the display image including a plurality of lines; an angle acquisition module for determining an angle between the projector and a normal line of the screen; and an image processing module for converting the input image Transforming the image into the display image includes: an angle correction module that deforms the input image according to the angle; a rescaling module for adjusting the size of the input image; and a brightness attenuator from the first line Initially, the brightness of the display image is adjusted by applying an increment of the brightness attenuation factor for each line. 37. The device for preventing keystone distortion in a projected image as described in item 36 of the scope of patent application, 08168twf1.doc / 006, with a correction date of 92.6.30, wherein the image processing module further includes a rotation module for The image is rotated ninety degrees. 38. A computer-readable storage medium storing instructions that, when executed by a computer, cause the computer to execute a method for generating an image from a projection system for projection without significant keystone distortion, wherein the projection of the projection system The axis is aligned with the video screen at a non-perpendicular angle, the method comprising the steps of: receiving an original image having a set of dimensions; maintaining a reference between a display device of the projection system and a plane parallel to the video screen A set of parameters of the geometric relationship; defining an available area of the display device in which a display of the original image can be provided; marking the original image for one or more parts of the available area A corresponding portion of the image; and providing features of the corresponding portion of the original image to produce a display image for projection on the video screen by the projection system; wherein the display image may be inconspicuous Projection is trapezoidal.