JP6398235B2 - Image projection apparatus, image projection system, and control method for image projection apparatus - Google Patents

Description

  The present invention relates to an image projection apparatus, an image projection system, and a control method for the image projection apparatus.

  As a typical display device used for a projector which is an example of an image projection apparatus, there is a DMD (Digital Micro mirror Device). The DMD is a device that creates an image with light reflected by tilting a fine mirror on silicon in units of pixels. Since it is a reflection system, it has excellent contrast, and since the response speed of the fine mirror can control each color of RGB (Red Green Blue) with a single chip, there is an advantage that the device can be easily downsized. is there.

  The DMD has a structure in which mirrors are physically arranged on a device, and the mirror is provided with an inclination of +10 degrees or -10 degrees, and the position of ON or OFF is taken. Depending on how the light is reflected at the on position or the off position, a switching operation with light such as 0 or 1 is provided.

  How the DMD makes the light turn on or off, the light emitted from the lamp hits the DMD device first and is reflected depending on whether the mirror is in the on or off position. The direction is determined. The light reflected by the ON position passes through the lens and is projected on the screen. When the mirror is in the off position, light is reflected in a direction that does not pass through the lens, so that a black image is reproduced on the screen. In other words, depending on whether the mirror is actually on or off, whether or not light is applied to the lens, an optical digital operation of 1 and 0 is realized.

  And since the mirror itself takes only one of the positions of on and off, the gray level is set by setting what is the on time on a certain time axis as the gradation. The key is on. That is, the mirror takes an on position or an off position (0 or 1), but an intermediate position between the on and off positions also passes instantaneously as a passing point. On a certain time axis, all white is assigned if all are on, all black if all are off, and half gray (intermediate gray) if 50% on and 50% off.

  A projector, which is an example of an image projection apparatus, is an apparatus that projects an image on a screen that is supposed to be projected on a screen with high flatness. However, in a normal use in an office or a field of application use where projection is performed on an irregular shaped object such as an exhibition display, projection onto a projection target for which flatness is not necessarily guaranteed is performed. Patent Document 1 has a problem in that apparent distortion of the projected image due to distortion of the screen becomes large, especially when the assumed standard observation direction of the projected image and the projection direction to the screen are significantly different. Are listed.

  With respect to such problems, in Patent Document 1 and the prior art document cited in Patent Document 1, points arranged in a grid pattern are projected on a screen as a pattern image, and this is imaged from an assumed observation direction. There is disclosed a method for correcting distortion of an input image to the projector by detecting distortion and reducing distortion from the observation direction. In particular, in Patent Document 1, as a method suitable for image distortion detection using an external camera, a background image of a flat portion is formed with an intermediate gradation, and a lower gradation level and a higher gradation level are defined based on this. A pattern configuration is disclosed in which the patterns are arranged in a staggered pattern in a lattice pattern.

  Patent Documents 2 and 3 disclose a technique for correcting image distortion caused by projection from a projector on a curved surface from the imaging result of a projected image of a regularly arranged circular pattern. In particular, Patent Document 2 assumes a projector disposed obliquely with respect to a free-form surface.

  The technical concept common to these patent documents is that image distortion is calculated based on the imaging results of the projected images of circular patterns arranged uniformly. However, in Patent Document 2 and Patent Document 3, the pattern itself is used. On the other hand, a device for improving robustness against disturbance is not particularly disclosed. On the other hand, Patent Document 1 is characterized in that a device for improving the contrast of a pattern is disclosed. Furthermore, Patent Document 1 is excellent in that it can perform hand-held shooting without the need to fix an external camera because distortion correction can be performed based on a single shot image of a projected pattern image.

  However, when projection onto a wall or the like that is not the original screen is assumed, various noises such as wall texture and dirt are superimposed on the captured pattern image (hereinafter referred to as “acquired pattern image”). . Accordingly, the projected pattern is required to have higher robustness against luminance unevenness and noise during shooting.

  In this regard, Patent Document 1 adopts a method in which a flat region is detected as an adjacent 4 × 4 luminance peak in the acquired pattern image or a midpoint of the luminance bottom, and a luminance gradient of the background is detected. For this reason, in order to reduce the pattern detection limit in an acquired pattern image in which the contrast has decreased due to the influence of external light or projection surface texture, it is required to correctly detect the peak (bottom) prior to the flat area detection. .

  On the other hand, in the present invention, in the distortion detection of the video projection system configured mainly with the projector as the image projecting means, the brightness of the background is detected without preceding detection of the peak (bottom) or flat area of the acquired pattern image. The gradient can be detected. Therefore, it is an object of the present invention to make it possible to detect distortion more robustly with respect to a decrease in contrast of an acquired pattern image and noise superimposition. In addition, distortion detection is realized with a single acquired pattern image, and convenience is not impaired. Further, even in the case where a part of the pattern (particularly the peripheral portion) is missing in the acquired pattern image, It is also a challenge to enable robust strain detection.

  Therefore, the present invention has been made in view of the above-described problems of the prior art, and is an image that can perform more robust distortion detection with respect to a decrease in contrast of a captured pattern image and noise superimposition. An object is to provide a projection device.

In order to solve the above problems, an image projection apparatus according to the present invention includes an image signal input unit that inputs an image signal projected on a projection plane, and a pattern image generation unit that generates a pattern image composed of a predetermined pattern shape A projection unit that projects the pattern image onto the projection plane; an imaging unit that captures the pattern image projected onto the projection plane; and a correction parameter that corrects distortion of an image signal based on the captured pattern image And a geometric distortion detecting means for calculating the image signal inputted from the image signal input means based on the calculated correction parameter, and constituting the predetermined pattern shape and brightness of the background which constitutes the average luminance of the pattern and the predetermined pattern is substantially V equal, the pattern image has a maximum brightness A first pattern image centered on one point, a second pattern image centered on a second point having a minimum brightness, and a background pattern having a brightness intermediate between the maximum brightness and the minimum brightness And the predetermined pattern shape is a repetitive shape in which the first pattern image and the second pattern image are staggered in a grid pattern with respect to the background pattern image. It is characterized by.

  ADVANTAGE OF THE INVENTION According to this invention, the image projector which can perform distortion detection more robust with respect to the contrast fall of the image | photographed pattern image or noise superimposition can be obtained.

It is a figure explaining the basic composition of the image projection system concerning this embodiment. It is a schematic block diagram explaining the structure of the image process part which performs the distortion correction incorporated in the projector which comprises the image projection system which concerns on this embodiment. It is a flowchart explaining the operation | movement of the image distortion correction process of the image process part which performs distortion correction incorporated in the projector which comprises the image projection system which concerns on this embodiment. It is a figure which shows the example of the pattern image projected by the projector which comprises the image projection system which concerns on this embodiment. It is the figure which represented typically the cross section of the luminance distribution as a projection image on the screen of the pattern image projected by the projector which comprises the image projection system which concerns on this embodiment. It is an enlarged view near the pattern 31b when a pattern image projected by a projector constituting the image projection system according to the present embodiment is constructed as a binary image. It is a figure which shows the other variation of the pattern 31b at the time of constructing | assembling the pattern image projected by the projector which comprises the image projection system which concerns on this embodiment as a binary image. It is a figure which shows the example of the user interface which performs the operation | movement of the image distortion correction of the image process part which performs the distortion correction incorporated in the projector which comprises the image projection system which concerns on this embodiment. In the image distortion correction operation of the image processing unit that performs distortion correction incorporated in the projector constituting the image projection system according to the present embodiment, (a) the (x, y) coordinate values on the acquired image of the pattern array are The figure which shows the case where acquisition of the pattern of (i, j + 1) element fails in the process of determining sequentially from top to bottom and left to right, (b) The case where two different patterns are arranged in a staggered arrangement FIG.

  According to the present invention, global smoothing sufficiently larger than each pattern size is performed on a pattern image including noise projected from a projector, particularly a projector assuming projection onto a non-planar surface. As a result, the average brightness of the pattern image can be made substantially equal to the background brightness, and the background brightness distribution is easily extracted before pattern extraction.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified thru | or abbreviate | omitted suitably.

  First, it is a figure explaining the basic composition of the image projection system concerning this embodiment. FIG. 1 is a diagram illustrating a basic configuration of an image projection system according to the present embodiment. In FIG. 1, an image projection system according to the present embodiment includes a projector 1 that is a main body of an image projection apparatus, and a personal computer (hereinafter referred to as a PC) 7 that is an example of an information processing apparatus that transmits a video signal to the projector 1. Consists of. Also, the screen 2 is a projection surface on which an image from the projector 1 is projected, and the camera 4 is an example of an imaging device that captures the projection image 9 projected on the screen 2.

  In particular, FIG. 1 illustrates a suspended screen 2 as the projection surface, but a wall surface or the like that does not have extreme irregularities or patterns may be substituted. Further, as the image input means, in addition to the normal camera 4, a mobile phone, a tablet PC, a notebook PC, or the like can be substituted if it is a device incorporating a camera.

  In this image projection system, in normal use, the user 8 projects the video from the PC 7 onto the screen 2 via the projector 1. When the screen 2 is distorted, the projected image 9 is also distorted. As described in Patent Document 1 described above, this distortion is caused by the difference between the projection direction of the image of the projector 1 and the observation direction of the projection image 9 by the user 8.

  In this case, the user 8 projects a pattern image 10 composed of an array of patterns, which will be described later, from the projector 1 and shoots this using the camera 4 from the viewpoint from which distortion is to be removed. Next, the user 8 captures the distorted projection image 9 of the captured pattern image 10 into the projector 1 directly via the communication means or via the PC 7. As will be described below, the projector 1 performs an image correction based on the acquired pattern image, thereby projecting an image without distortion as viewed from the viewpoint of the user 8.

  Next, the configuration of an image processing unit that performs distortion correction incorporated in the projector that configures the image projection system according to the present embodiment will be described. FIG. 2 is a schematic block diagram illustrating the configuration of an image processing unit that performs distortion correction incorporated in the projector that configures the image projection system according to the present embodiment.

  In FIG. 2, the video signal input unit 18 normally receives the video signal from the PC 7 and sends it to the subsequent processing. When there is a signal transmission request from the pattern image generation unit 17, the pattern image generation unit 17. The signal from is prioritized and sent to subsequent processing. When projecting the pattern image 10 for image distortion detection, the user 8 applies to the pattern image generation unit 17 which is a pattern image generation unit via the instruction unit 16 provided in the projector 1 or the utility software on the PC 7. The generation of the pattern image 10 is instructed. The pattern image generation unit 17 sends the instructed pattern image signal to the video signal input unit 18.

  On the other hand, as described above, the pattern image 10 acquired via the camera 4 or the PC 7 is accumulated in the buffer 19. The geometric distortion detection unit 20, which is a geometric distortion detection means, calculates a correction parameter from the distorted pattern image stored in the buffer 19. The image distortion correction unit 21 serving as an image distortion correction unit develops the video signal acquired from the PC 7 to the video signal input unit 18 on the frame memory 22, and based on the correction parameter calculated by the geometric distortion detection unit 20. To correct. The corrected video signal is projected from the projection unit 23 onto the screen 2 as the projection image 9.

  Although not specifically shown in FIG. 2, the image distortion correction unit 21 responds to the video signal from the video signal input unit 18 in accordance with an instruction from the instruction unit 16 or an instruction from utility software on the PC 7. Image distortion correction can be switched on and off. FIG. 2 shows the flow of processing in an implementation in which image distortion correction processing is performed on the projector 1 side.

  However, these pattern image generation means, geometric distortion detection means, and image distortion correction means can also be implemented as software on the PC 7 side. In the following description, the image processing by the processing module of utility software installed on the PC 7 is simply described as the processing of the PC 7.

  Next, the operation of the image distortion correction process of the image processing unit that performs distortion correction incorporated in the projector constituting the image projection system according to the present embodiment will be described. FIG. 3 is a flowchart for explaining the operation of the image distortion correction processing of the image processing unit that performs distortion correction incorporated in the projector constituting the image projection system according to the present embodiment.

  Each process described below is generally the same when each processing means is mounted in the projector 1 as shown in FIG. 2, but here, it will be described assuming that it is realized by software on the PC 7.

  In the first step 1, as described above, the user 8 uses the user interface 40 (detailed in FIG. 8 described later) implemented by the utility software of the PC 7 to correspond to the pattern used for distortion detection. Give the instruction parameter. The software module as the pattern image generation means generates a pattern image as shown in FIG. 4 based on the instruction parameter. FIG. 4 is a diagram illustrating an example of a pattern image projected by the projector that constitutes the image projection system according to the present embodiment.

  There are two methods for generating a pattern image at this time. One is an implementation in which a plurality of pattern images held in advance are selected as pattern identification numbers as instruction parameters from the instruction unit 16 (FIG. 2). The other is a mounting method in which a shape parameter (for example, a radius of a circle) corresponding to a pattern shape is designated as an instruction parameter, and the pattern image generation unit 17 generates a pattern image by calculation processing. Details of the pattern generated at this time will be described later.

  In step 2, the generated pattern image is sent to the video signal input unit 18 of the projector 1 and projected onto the screen 2. In step 3, the pattern image 10 projected on the screen 2 is captured by the camera 4 and transmitted to the PC 7. At this time, if the camera 4 is a device having a communication function such as a camera-equipped mobile phone, pattern image data can be directly exchanged between the camera 4 and the PC 7. When the camera 4 does not have a communication function, the user 8 transfers the pattern image data to the PC 7 through the recording medium of the camera 4.

  In step 4, localized noise is removed by applying local smoothing that is sufficiently smaller than the individual pattern size to the pattern image 10 including distortion and noise acquired in step 3.

  On the other hand, in step 5, global smoothing sufficiently larger than the individual pattern size is performed on the pattern image 10 including distortion and noise acquired in step 3. Thereby, the gentle brightness gradient of the whole image is removed. At this time, the pattern image 10 is designed so that the average luminance of the pattern is substantially equal to the background luminance, as will be described later. For this reason, there is almost no pattern component remaining after the global smoothing process in step 5, and a decrease in contrast in the difference calculation in the next step 6 is prevented.

  In step 6, by taking the difference between the processing result of step 4 and the processing result of step 5, the background luminance of the pattern image is normalized to 0. In step 7, the center point of each pattern in the pattern image is calculated based on the processed image in step 6. Here, first, the rough peak / bottom value is used as an initial value of the estimated value of each center point, and for each center point, the coordinate value (xα, yα) of the center point with high accuracy is calculated from the luminance gradient in the vicinity. calculate. However, α is a subscript for simply extracting and identifying the peak value pα, and is not associated with the pattern position of the pattern image data. Further, the coordinate value here may be considered as a real number extension of the subscript of the captured image array.

  In step 8, matching is confirmed between each peak value pα acquired in step 7 and the list of coordinate values (xα, yα). If there is a missing point, the missing point is estimated and compensated from the surrounding peak value and its coordinate value, and each coordinate value (xα, yα) and the subscript (i as an array of the pattern of the original pattern image data) , J).

  In step 9, based on (i, j, xα, yα) associated in step 8, distortion correction parameters are calculated by a method similar to the method described in Patent Document 1. At step 10, the distortion of the output video is correctly corrected by setting the distortion correction parameter obtained at step 9 to the image correction software module as the geometric distortion correcting means.

  In FIG. 4 showing an example of the pattern image 10, the pattern image 10 has a pattern 31 a centering on a white point having the maximum luminance and a black point having the minimum luminance on the background portion 30 having the intermediate luminance. The pattern 31b to be formed is configured in a latticed staggered arrangement. In addition, the area ratio of white and black is adjusted so that the average brightness as the output of the projector 31 for each of the patterns 31a and 31b is substantially equal to the background brightness. Note that the actual pattern image is composed of a region in which the pattern image 10 of FIG. 4 is connected approximately vertically and horizontally by 2 × 2, but for convenience of illustration, FIG. 4 illustrates a quarter region.

  Next, a cross section of the luminance distribution as a projection image of the pattern image projected by the projector constituting the image projection system according to this embodiment will be described. FIG. 5 is a diagram schematically showing a cross section of the luminance distribution as a projection image of the pattern image projected by the projector constituting the image projection system according to the present embodiment onto the screen.

  In FIG. 5, the position of the horizontal axis corresponds to the AA ′ cross section of FIG. Both the pattern 31a and the pattern 31b ensure high contrast by combining black and white concentric circles, and the detection of the peak 32 and the bottom 33 is robust against disturbance. Further, by increasing the luminance gradient around the peak 32 and the bottom 33, the convergence and accuracy of the extreme value detection calculation at step 7 in FIG. 3 are improved.

  Next, an enlarged view of the vicinity of the pattern 31b when a pattern image projected by the projector constituting the image projection system according to the present embodiment is constructed as a binary image will be described. FIG. 6 is an enlarged view of the vicinity of the pattern 31b when a pattern image projected by the projector constituting the image projection system according to the present embodiment is constructed as a binary image.

  In FIG. 6, the pattern 31b is configured so that the number of white dots and the number of black dots are the same in the entire region. Thereby, by making the monochrome area ratio of the background portion 30 and the monochrome area ratio of the pattern 31b equal, the background luminance and the average luminance of the pattern 31b are made substantially equal regardless of the intermediate gradation characteristics of the projector 1. Can do. Further, the above-described local smoothing in step 4 of FIG. 3 eliminates fine luminance unevenness caused by this background pattern, so that an inappropriate moire (stripe) is generated in step 6 that takes a difference from the global smoothing in step 5. It prevents it from happening.

  Next, other variations of the pattern 31b when the pattern image projected by the projector constituting the image projection system according to the present embodiment is constructed as a binary image will be described. FIG. 7 is a diagram showing another variation of the pattern 31b when a pattern image projected by the projector constituting the image projection system according to the present embodiment is constructed as a binary image.

  In FIG. 7, the patterns 35b, 36b, 37b, and 38b are set to have the same area ratio of white and black as in the pattern 31b. In each pattern, the ratio of the diameter (inner diameter) of the innermost circle to the diameter (inner diameter) of the outermost circle is 0.2 for the pattern 35b, 0.3 for the pattern 36b, 0.4 for the pattern 31b, The pattern 37b is set to 0.5 and the pattern 38b is set to 1 / √2. Corresponding patterns 35a to 38a (not shown) are also defined as black and white inverted graphics of these patterns.

  In this way, by constructing the pattern as triple concentric circles, it becomes possible to give a certain degree of freedom to the ratio between the central circle and the black and white inversion area surrounding it. From these patterns, by selecting a projection image having a high contrast suitable for detecting the peak value or the bottom value in accordance with the actual use environment, distortion detection more robust against environmental noise can be performed.

  Further, by constructing a pattern image with binary image data of two colors of black and white, the average of the pattern image can be obtained without depending on the γ setting value for setting the ratio between the signal level of the input video and the brightness of the output video in the projector. The luminance can be made approximately equal to the background luminance. This is based on the assumption that the energy of the projection light emitted from the projector is approximately proportional to the number of pixels that are turned on. That is, the amount of light emitted from the projector is controlled spatially (in terms of area) with binary image data, so that the pattern image designer mainly controls the pattern image.

  On the other hand, as described above, the brightness of the intermediate gradation is controlled by the time when the DMD is turned on. Therefore, when a pattern image is not constructed with binary image data, distortion correction depends on the design on the DMD control side that is made into a black box, and is affected by the gradation characteristics of the projector and the camera itself. There's a problem. On the other hand, by using the pattern image according to the present embodiment, the average luminance of the pattern image can be made to substantially match the background luminance without being restricted by the convenience of already installed gradation characteristics such as a projector and a camera. Can do it.

  Next, an example of a user interface that executes an image distortion correction operation of an image processing unit that performs distortion correction incorporated in the projector constituting the image projection system according to the present embodiment will be described. FIG. 8 is a diagram illustrating an example of a user interface that executes an image distortion correction operation of an image processing unit that performs distortion correction incorporated in a projector included in the image projection system according to the present embodiment.

  In FIG. 8, the user interface 40 mainly includes a preview display area 52 for displaying a pattern preview, a slider 41 for selecting a first pattern, and a slider 43 for selecting a second pattern. Further, it comprises a reverse switch 45 for the first pattern, a reverse switch 46 for the second pattern, and a pattern projection instruction button 47. The preview display area 52 is provided with an enlarge button 48 and a reduce button 49 for instructing enlargement / reduction of the display image.

  The first pattern and the second pattern correspond to the first pattern 50 and the second pattern 51 that are displayed in the preview display area 52 and have a staggered arrangement with each other. Further, the slider 41 is set with five selection positions. By indicating the selection position with the handle 42, one of the corresponding inversion patterns shown in FIG.

  Here, when the reversing switch 45 is checked, the pattern of FIG. 7 is associated as it is. Similarly, the second pattern is selected using the slider 43, the handle 44, and the reverse switch 46. Therefore, in the state shown in FIG. 8, the reverse pattern of the pattern 35b of FIG. 7 is selected as the first pattern (pattern 50), and the pattern 37b of FIG. 7 is selected as the second pattern (pattern 51).

  The projection instruction button 47 is a toggle button, and when pressed, the pattern image is preferentially projected from the projector 1 until it is pressed again. In particular, such a switching operation is performed according to the following procedure when the pattern image generation unit 17 is incorporated in the projector 1 as shown in FIG. That is, an instruction from the user interface of the PC 7 is performed by switching the input of the video signal input unit 18 received via the communication unit 15 and the instruction unit 16. On the other hand, when generating the pattern image or the like in the utility software on the PC 7 side, the video signal itself sent from the PC 7 to the projector 1 is switched.

  Finally, the handling of the missing value described in step 8 of FIG. 3 will be supplementarily described with reference to FIG. FIG. 9 is a diagram for explaining the image distortion correction operation of the image processing unit that performs distortion correction incorporated in the projector constituting the image projection system according to the present embodiment. FIG. 9A shows how to acquire a pattern of (i, j + 1) elements in the process of sequentially determining (x, y) coordinate values on an acquired image of a pattern array in order from top to bottom and from left to right. It is a figure which shows the case where it fails. FIG. 9B is a diagram showing a case where two different patterns are arranged in a staggered arrangement.

  As shown in FIG. 9 (a), when all patterns are composed of the same pattern, the element (i, j) that has not yet been determined as viewed from the (i, j) element is the most (i, j) element. Let us consider a case in which elements close to are associated as (i, j + 1) elements. If it does so, the problem that the matching shown with the broken line of Fig.9 (a) which should be selected will fail will arise.

  On the other hand, as shown in FIG. 9B, when two different patterns are arranged in a staggered arrangement, the element is an undetermined element closest to the (i, j) element (i, j + 1). However, it becomes the same pattern as the (i, j) element. From this, it is possible to easily detect that the pattern (i, j + 1) is missing. In this case, based on the already determined (i, j), (i-1, j + 1), (i-1, j + 2) determined elements and the previously detected (i, j + 1), the missing elements (I, j + 1) can be estimated by linear interpolation.

  The interpolation process in the case where the missing pixel is a peripheral part is different from the interpolation process described with reference to FIG. 9, but the same type of pattern continues if there are a small number of defects. Therefore, the missing value can be determined at an early stage of the algorithm, whereby efficient missing value interpolation processing can be realized.

  As described above, according to the present invention, sufficient smoothing processing is performed on a single captured pattern image acquired by the input means for correcting the pattern image projected from the projector. . This makes it possible to extract the background luminance distribution before identifying the peak or bottom of the pattern image individually.

  Further, even when a slight pattern defect occurs in the captured pattern image, it is easy to infer and interpolate the defect pattern from the relationship with the peripheral pattern. Furthermore, by configuring the pattern arrangement in a staggered arrangement, the luminance ranges of the two types of patterns are combined as different ones. Thereby, the local contrast of the acquired pattern image is ensured and the more stable pattern detection becomes possible.

  In addition, as a pattern that substantially matches the average luminance of the pattern and the background luminance, it is possible to optimize the pattern in order to ensure more appropriate contrast by providing a degree of freedom in setting the concentric inner diameter ratio. It becomes possible. Since the pattern image is configured as a binary image, the average luminance of the pattern image and the average luminance of the background image can be made substantially equal without being affected by the setting value of the gradation characteristics in the projector or camera. Furthermore, the user can adjust the pattern image that provides the optimum contrast according to the situation of the projector installation site.

  In addition, each operation | movement of each functional block which comprises the image projection system which concerns on this embodiment shown in FIG. 3 can also be made to perform the program on a computer. That is, a control unit (not shown) in the projector 1 or a CPU (not shown) in the PC 7 loads a program stored in a storage medium such as a ROM. This is realized by sequentially executing each processing step of the program.

  According to the present invention, an image projection apparatus, an image projection system, and an image projection apparatus control method capable of performing more robust distortion detection with respect to contrast reduction and noise superposition of a captured pattern image are obtained. It is done.

  The present invention has been described above by the preferred embodiments of the present invention. While the invention has been described with reference to specific embodiments thereof, various modifications and changes can be made to these embodiments without departing from the broader spirit and scope of the invention as defined in the claims. is there.

1 Projector 2 Screen 4 Camera 7 PC
DESCRIPTION OF SYMBOLS 8 User 9 Projected image 10 Pattern image 15 Communication means 16 Instruction part 17 Pattern image generation part 18 Video signal input part 19 Buffer 20 Geometric distortion detection part 21 Image distortion correction part 22 Frame memory 23 Projection part 30 Background part 31, 35, 36 , 37, 38 Pattern 32 Peak 33 Bottom 40 User interface 41, 43 Slider 42, 44 Handle 45, 46 Invert switch 47 Pattern projection instruction button 48 Enlarge button 49 Reduce button 50 First pattern 51 Second pattern 52 Preview display area

JP 2013-172444 A JP 2001-083949 A JP 2008-113416 A

Claims (8)

An image signal input means for inputting an image signal projected on the projection surface;
Pattern image generation means for generating a pattern image composed of a predetermined pattern shape;
Projecting means for projecting the pattern image onto the projection plane;
Imaging means for imaging the pattern image projected on the projection plane;
Geometric distortion detecting means for calculating a correction parameter for correcting distortion of an image signal based on the captured pattern image;
Image distortion correction means for correcting the image signal input from the image signal input means based on the calculated correction parameter;
Including
The predetermined pattern shape and the average luminance of the pattern constituting the luminance of the background constituting the predetermined pattern is substantially V equal,
The pattern image includes a first pattern image centered on a first point having a maximum brightness, a second pattern image centered on a second point having a minimum brightness, the maximum brightness, and the minimum brightness. And a background pattern image having an intermediate brightness,
The predetermined pattern shape is a repetitive shape in which the first pattern image and the second pattern image are arranged in a staggered pattern in a grid pattern with respect to the background pattern image. An image projection device. The pattern image is a binary image of black and white colors, the first point is the point of the white image according to claim 1, wherein the second point is the point of black Projection device. The first pattern image and said second pattern image, the image projection apparatus according to claim 1 or 2, characterized in that it consists of triple concentric circles. Wherein the first pattern image and the second area ratio of the point of the white area ratio and the black points occupying the pattern image, an image according to claim 2 or 3, characterized in that equal Projection device. In order to make the area ratio of the white dots and the area ratio of the black dots occupying the first pattern image and the second pattern image equal, the inner diameter ratio of each of the triple concentric circles is the image projection apparatus according to claim 3 or 4, further comprising means for setting. The geometric distortion detecting means corrects the distortion of the image signal input from the image signal input means based on the captured pattern image. When the captured pattern image has a missing value, the geometric distortion detection means the image projection apparatus according to any one of claims 1, wherein the estimating the missing values based on the determined elements of the pattern images existing in the periphery of the value 5. An image projection system comprising: an image projection device that projects an image on a projection surface; an information processing device that controls the operation of the image projection device; and an imaging device that captures an image projected on the projection surface,
The image projector is
Image signal input means for inputting an image signal projected onto the projection plane;
Projecting means for projecting a pattern image composed of a predetermined pattern shape onto the projection plane,
The imaging device
Including imaging means for imaging the pattern image projected on the projection plane;
The information processing apparatus includes:
Pattern image generation means for generating the pattern image;
Geometric distortion detecting means for calculating a correction parameter for correcting distortion of an image signal based on the captured pattern image;
Image distortion correction means for correcting the image signal input from the image signal input means based on the calculated correction parameter;
Only including,
The average luminance of the pattern constituting the predetermined pattern shape and the luminance of the background constituting the predetermined pattern shape are substantially equal,
The pattern image includes a first pattern image centered on a first point having a maximum brightness, a second pattern image centered on a second point having a minimum brightness, the maximum brightness, and the minimum brightness. And a background pattern image having an intermediate brightness,
The predetermined pattern shape is a repetitive shape in which the first pattern image and the second pattern image are arranged in a staggered pattern in a grid pattern with respect to the background pattern image. Image projection system. A method for controlling an image projection apparatus, comprising:
Inputting an image signal to be projected on the projection surface;
Generating a pattern image composed of a predetermined pattern shape;
Projecting the pattern image onto the projection plane;
Capturing the pattern image projected on the projection plane;
Calculating a correction parameter for correcting distortion of the image signal based on the pattern image imaged in the imaging step;
Correcting the image signal input by the step of inputting the image signal based on the correction parameter calculated by the step of calculating;
Making the average luminance of the pattern constituting the predetermined pattern shape substantially equal to the luminance of the background constituting the predetermined pattern shape;
Only including,
The pattern image includes a first pattern image centered on a first point having a maximum brightness, a second pattern image centered on a second point having a minimum brightness, the maximum brightness, and the minimum brightness. And a background pattern image having an intermediate brightness,
The predetermined pattern shape is a repetitive shape in which the first pattern image and the second pattern image are arranged in a staggered pattern in a grid pattern with respect to the background pattern image. Control method to do.

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