JP5251010B2 - Image processing device, projector - Google Patents

Description

  The present invention relates to image processing for a projector, and more particularly to a technique for correcting distortion of an image displayed on a projection surface.

  A projector normally displays an image on a projection surface by tilt projection. What is tilt projection? This means a projection method when the light source optical axes of the projector do not intersect perpendicularly to the projection plane. Since an image projected on the projection plane by tilt projection is displayed distorted, some projectors have various correction functions for displaying an image with suppressed distortion on the projection plane. The correction function includes, for example, distortion of an image displayed on the projection surface by forming a distorted image on an image forming unit such as a liquid crystal light valve provided inside using an angle parameter related to the projection angle of the projector. There are an angle designation correction function for correcting the image, a four-corner designation correction function for correcting the image based on a displacement amount corresponding to a user operation at the positions of the four corners of the image displayed on the projection plane, and the like.

  When using a projector equipped with a plurality of such correction functions, the user switches the correction function currently set in the projector to a correction function desired to be used, and executes image correction.

Japanese Patent Laid-Open No. 2002-15896 JP 2004-140845 A JP 2003-304552 A JP 2003-330102 A

  However, when switching to the angle designation correction function after image correction by the four corner designation correction function, there is a problem that it is difficult to switch to the angle designation correction function while maintaining the shape of the image corrected by the four corner designation correction function. This occurs because the angle parameter used for the angle designation correction function is not corrected in conjunction with the correction by the four corner designation correction function. Therefore, when switching from the four corner designation correction function to the angle designation correction function, the image displayed on the screen returns to the shape before correction by the four corner designation correction function.

  The present invention has been made in view of the above-described problems, and an object thereof is to suppress a change in the shape of an image displayed on a projection surface before and after switching of a correction function of a projector having a plurality of types of correction functions.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
The image processing apparatus of Application Example 1 is used in a projector including an image forming unit that forms an image to be displayed on a projection surface using image data. The image processing apparatus of Application Example 1 includes first corrected image data in which distortion of the display image is corrected from original image data in accordance with a change of a correction point displayed on the display image projected on the projection plane. And a projection angle of the projector based on shape information relating to a shape of the first distortion image formed in the image forming unit using the first correction image data. An initial value generating means for generating an initial value of the angle parameter such that the shape of the image represented by the image data generated by the correction using the angle parameter has substantially the same shape as the first distortion image; and the angle A second corrected image data generating unit configured to generate second corrected image data in which distortion of the display image is corrected from original image data in accordance with a change in the parameter; A second corrected image data generating unit configured to generate the second corrected image data using the generated initial value when the period value is generated;

  According to the image processing apparatus of Application Example 1, when the correction by the second correction image data generation unit is performed after the correction by the first correction image data generation unit, the first after correction by the first image data correction method is performed. From the shape of the distorted image, the initial value of the angle parameter can be generated so that the second image data correction method can generate image data representing an image having substantially the same shape as the first distorted image. Therefore, the correction by the second image data correction unit can be executed while maintaining the shape of the image corrected by the first image data correction unit. Therefore, it is possible to suppress a change in the shape of the image displayed on the projection surface before and after correction by different correction means. When the correction is performed using the second image data correction unit after the correction by the first image data correction unit, the user can efficiently correct the image because the change in the shape of the image displayed on the projection plane is small.

  In the image processing apparatus according to the application example 1, the image data generation unit to be output to the image forming unit is further connected between the first correction image data generation unit and the second correction image data generation unit. The initial value generating means generates the initial value when switching from the first corrected image data generating means to the second corrected image data generating means, and the second correction The image data generation means generates the second corrected image data using the initial value at the time of switching.

  According to the image processing apparatus of Application Example 1, an initial value can be generated when switching from the first corrected image data generating unit to the second corrected image data generating unit. Therefore, before and after switching from the first corrected image data generating means to the second corrected image data generating means, the shape of the image formed in the image forming portion can be made substantially the same.

In the image processing apparatus of Application Example 1, the shape of the first distortion image includes a quadrangle,
The initial value generating means acquires, as the shape information, position information regarding the positions of the four corners of the first distorted image, and a calculation means for calculating the initial value using the acquired position information. And comprising.

  According to the image processing apparatus of Application Example 1, the initial values can be calculated from the positions of the four corners of the first distorted image formed in the image forming unit. Therefore, the initial value of the angle parameter can be generated using position information that can be easily acquired, and the processing load of the image processing apparatus can be reduced.

  In the image processing apparatus according to the application example 1, the calculation unit is configured such that an inclination of an edge of an image represented by the second image data generated using the initial value is an inclination of an edge of the first distortion image. The initial value is calculated so as to be substantially the same.

  According to the image processing apparatus of Application Example 1, it is possible to form the second distortion image while maintaining the inclination of each side of the first distortion image. Therefore, the shape change of the image displayed on the projection plane can be accurately suppressed before and after the correction of the first image data correction method and the second image data correction method.

  In the image processing apparatus of Application Example 1, the calculation unit includes vertical vanishing point position information (Vx, Vy) indicating the position of the vanishing point in the vertical direction of the first distortion image defined by the shape information and the horizontal direction. Applying the horizontal vanishing point information (Hx, Hy) representing the position of the vanishing point to Equation 1 to calculate intermediate values Vz ′ and Hz ′ for calculating the initial values (ψ, θ, φ), The intermediate values are applied to Equation 2 to calculate the initial values (ψ, θ, φ).

  According to the image processing apparatus of application example 1, the angle parameter can be calculated using the vanishing point of the first distorted image. Therefore, the angle parameter can be calculated easily and accurately.

  The projector according to the application example 2 includes the image processing apparatus according to the application example 1, the light source, the first correction image data or the second correction image data input from the image processing apparatus, and the light emitted from the light source. And an image forming unit that forms an image to be displayed on the projection surface, and a projection optical system that projects the emitted light output from the image forming unit onto the projection surface.

  According to the projector of Application Example 2, before and after switching from the first corrected image data generation unit to the second corrected image data generation unit, the second shape is maintained so as to substantially maintain the shape of the image projected on the projection surface. The initial value of the angle parameter used in the image data generating means can be generated. Therefore, the projector of Application Example 2 can display substantially the same image on the projection plane before and after switching. Therefore, the user can continue correction from the shape corrected before switching from the first corrected image data generating unit to the second corrected image data generating unit. Therefore, since the user can correct smoothly and efficiently, the convenience for the user can be improved.

  In the present invention, the various aspects described above can be applied by appropriately combining or omitting some of them. In addition to the configuration as the image processing apparatus described above, the present invention records an image processing method by the image processing apparatus, a computer program for causing the image processing apparatus to execute image processing, and the computer program recorded in a computer-readable manner. It can also be configured as a recording medium. In any configuration, the above-described aspects can be appropriately applied. As a computer-readable recording medium, various media such as a flexible disk, a CD-ROM, a DVD-ROM, a magneto-optical disk, an IC card, and a hard disk can be used.

A. Example:
A1. Function block:
FIG. 1 is a block diagram illustrating the configuration of the projector PJ in the embodiment. The projector PJ includes an illumination optical system 100, a liquid crystal light valve 300, and a projection optical system 340. In FIG. 1, each optical system is shown in a simplified manner. The projector PJ includes a light source lamp driving unit 110, a liquid crystal light valve driving unit 310, a projection optical system adjustment unit 350, a CPU 400, an image input unit 410, an image processing unit 420, and an operation unit 510. CPU 400 controls the overall operation of projector PJ.

  The light source lamp driving unit 110 drives a light source lamp included in the illumination optical system 100. The liquid crystal light valve driving unit 310 drives the liquid crystal light valve 300 according to the image data given from the image processing unit 420.

  The operation unit 510 causes the CPU 400 to execute various processes in response to input from the user. For example, the user can change parameters used for image distortion correction processing or adjust the contrast of the image projected on the screen SC via the operation unit 510.

  The projection optical system adjustment unit 350 adjusts the position of the projection optical system 340. Specifically, the projection optical system adjustment unit 350 moves the lens included in the projection optical system 340 or adjusts the shift position in a direction parallel to the light source optical axis LA. The light source optical axis means the central axis of light emitted from the illumination optical system 100 and passes through the center of the image projected by the liquid crystal light valve 300 on the screen SC.

  The image input unit 410 transfers image data given from the outside to the image processing unit 420. For example, the image input unit 410 reads image data stored in the memory card MC, and transfers the image data to the image processing unit 420.

  The image processing unit 420 processes the image data transferred from the image input unit 410, generates corrected image data from the input image data, and transfers the corrected image data to the liquid crystal light valve driving unit 310. When an image is displayed on the screen SC by tilt projection, when an undistorted rectangular image is formed on the liquid crystal light valve 300, the image displayed on the screen SC is distorted into a substantially trapezoidal shape. Conversely, if an image distorted substantially on a trapezoid is formed on the liquid crystal light valve 300, an image without distortion can be displayed on the screen SC. Hereinafter, in the embodiment, a distorted image formed on the liquid crystal light valve 300 is referred to as a “distortion image”, and an outer shape of the distortion image is referred to as a “distortion image shape”. The distortion correction unit 430 corrects input image data to generate corrected image data representing a distortion image. When a distorted image is formed on the liquid crystal light valve 300 according to the corrected image data, a rectangular image is displayed on the screen SC.

  Specifically, the image processing unit 420 includes a computer program that functions as the distortion correction unit 430. The distortion correction unit 430 includes a four-corner designation correction module 432, an angle designation correction module 434, and a switching control module 438. Is provided.

  The four-corner designation correction module 432 corrects the shape of the distorted image formed on the liquid crystal light valve 300 based on the amount of displacement of the correction point displayed on the projection plane according to the user operation, and displays the image displayed on the projection plane. Correct distortion.

  The angle designation correction module 434 corrects the distortion of the image displayed on the projection plane by correcting the shape of the distortion image formed on the liquid crystal light valve 300 according to the change amount of the angle parameter input by the user. .

  The switching control module 438 switches which one of the four corner designation correction module 432 and the angle designation correction module 434 is used to form a distorted image. The switching control module 438 determines the shape of the image displayed on the projection plane, that is, the shape of the distorted image formed on the liquid crystal light valve 300, before and after switching from the four corner designation correction module 432 to the angle designation correction module 434. The angle parameter is set from the shape of the distorted image corrected by the four corner designation correction module 432 so as to be substantially the same. Hereinafter, in the embodiment, the correction method by the four corner designation correction module 432 is called a four corner designation correction method, and the correction method by the angle designation correction module 434 is called an angle designation correction method.

  With the configuration as described above, the projector PJ substantially changes the shape of the image displayed on the projection surface when switching from the four corner designation correction module 432 to the angle designation correction module 434 in accordance with an instruction from the user. Switching can be performed while the image is maintained, and correction by the angle designation correction module 434 can be continued from the shape of the image corrected by the four corner designation correction module 432.

A2. Correction method:
A2-1: Four corner designation correction method:
The correction method in the embodiment will be described with reference to FIGS. FIG. 2 is an explanatory diagram for explaining a four-corner designation correction method in the embodiment. FIG. 2A shows the image shape displayed on the screen, and FIG. 2B shows the liquid crystal light valve 300 formed when the image displayed on the screen is FIG. The shape of the distorted image is shown. In FIG. 2A, correction points Ps1, Ps2, Ps3 and Ps4 represent the four corners of the image displayed on the screen SC. In FIG. 2B, correction points Pv1, Pv2, Pv3 and Pv4 are These points correspond to the correction points Ps1, Ps2, Ps3 and Ps4 (FIG. 2A).

  The four-corner designation correction method corrects the distortion of the image displayed on the screen by correcting the positions of the correction points Pv1, Pv2, Pv3, and Pv4 in accordance with a correction instruction input from the user via the operation unit 510. To do.

  FIG. 3 is an explanatory diagram illustrating the operation unit 510 in the embodiment. The operation unit 510 is installed on, for example, the upper surface of the projector PJ. The operation unit 510 includes distortion correction buttons BT1, BT2, BT3, BT4, a correction point selection button BT5, a correction method switching button BT10, and a selection correction method display unit 20, as shown in FIG.

  The selection correction method display unit 20 represents a currently selected correction method, and is configured by, for example, an LED. For example, when the four-corner designation correction method is selected, as shown in FIG. 3, the LED 21 indicating the four-corner designation correction method is turned on, and the LED 22 indicating the angle designation correction method is turned off.

  When the correction point selection button BT5 is pressed, the four corner designation correction module 432 sequentially selects the correction points Ps1, Ps2, Ps3, and Ps4. When the distortion correction buttons BT1, BT2, BT3, and BT4 are pressed, the four corner designation correction module 432 selects correction points corresponding to the correction points on the selected projection plane among the correction points Pv1, Pv2, Pv3, and Pv4. , And move in the direction indicated by each distortion correction button (any one of the arrows AR1, AR2, AR3 and AR4 shown in FIG. 2B). For example, when the correction point Ps1 is selected and the distortion correction button BT3 is pressed, the four corner designation correction module 432 moves the correction point Pv1 in the AR3 direction according to the number of times of pressing, as shown in FIG. . The correction point Pv1 is moved to the correction point Pv1 '. As a result, the correction point Ps1 on the screen corresponding to the correction point Pv1 of the distortion image of the liquid crystal light valve 300 is moved by the amount of movement corresponding to the number of times the distortion correction button BT3 is pressed. Therefore, the correction point Ps1 is moved to the correction point Ps1 '. In this way, the four corner designation correction method corrects the distortion of the image displayed on the screen SC.

A2-2. Angle designation correction method:
A2-2-1. Angle parameter:
The angle designation correction method will be described with reference to FIGS. The angle designation correction method is a method for correcting image data in consideration of the tilt of the projector with respect to the screen SC, that is, the projection angle. FIG. 4 is an explanatory diagram illustrating an angle (projection angle) between the projector and the screen SC in the embodiment. FIG. 5 is an explanatory diagram illustrating an angle parameter correction screen WD in the embodiment. FIG. 6 is an explanatory diagram for explaining a correction shape of an image by the angle correction method in the embodiment. In FIG. 4, the space in which the projector and the screen SC are installed is indicated by an xyz coordinate system. As shown in FIG. 4, in the embodiment, the projector PJ is installed on a plane parallel to the xz plane, and the screen SC is a plane parallel to the xy plane. The projection angle in the horizontal direction (X axis) of the projector is represented by pitch θ, the projection angle in the vertical direction (Y axis) of the projector is represented by yaw φ, and the rotation angle about the normal line (Z axis) of the screen SC is represented by roll ψ. . When the projector PJ is rotated around the x axis and projected vertically, the inclination of the vertical side of the image displayed on the screen changes, and when it is rotated around the Y axis and projected horizontally, it is displayed on the screen. When the inclination of the horizontal side of the image to be changed is changed and rotated about the Z axis, the image displayed on the screen is rotated about the screen normal.

  The angle designation correction method uses the angle parameter θ used for correcting the vertical side of the image displayed on the screen SC and the horizontal side correction of the image displayed on the screen SC in consideration of the rotation of the above three types of axes. The angle parameter φ and the angle parameter ψ used to correct the rotation of the image displayed on the screen SC are input to the angle designation correction module 434, thereby correcting the distortion of the image displayed on the screen.

  With reference to FIG. 5, an input method of each angle parameter θ, φ, ψ will be described. Each angle parameter θ, φ, ψ is input according to a user operation. The angle parameter correction screen WD includes a vertical side correction slide bar SL1, a horizontal side correction slide bar SL2, and a rotation correction slide bar SL3. Marks MK1 to MK3 representing the current angle parameters θ, φ, and ψ are displayed on the slide bars SL1 to SL3, respectively. The selection frame TG shows a correction target slide bar surrounded by a frame. The amount of movement of each slide bar in the left-right direction in the drawing is linked to the amount of correction of each angle parameter θ, φ, ψ. In the embodiment, the movement amount of the vertical side correction slide bar SL1 and the correction amount of the angle parameter θ are linked, and the inclination of the vertical side of the distorted image formed on the liquid crystal light valve 300 is corrected. Further, the movement amount of the horizontal side correction slide bar SL2 and the correction amount of the angle parameter φ are linked, and the inclination of the horizontal side of the distorted image formed on the liquid crystal light valve 300 is corrected. In addition, the movement amount of the rotation correction slide bar SL3 and the correction amount of the angle parameter ψ are linked to correct the rotation direction inclination of the distorted image formed on the liquid crystal light valve 300.

  For example, the user selects the horizontal correction slide bar SL2 via the operation unit 510, and presses the correction buttons BT3 and BT4 (FIG. 3) of the operation unit 510 to display the mark MK on the horizontal correction slide bar SL2 on the left and right sides of the drawing. Move in the direction. The angle designation correction module 434 corrects the angle parameter φ linked to the selected horizontal side correction slide bar SL2 in accordance with the number of times the correction button BT3 or BT4 is pressed. By doing so, as shown in FIG. 6A, the angles of the horizontal sides 51 and 52 of the distorted image 50 formed on the liquid crystal light valve 300 change as indicated by the broken line. As a result, as shown in FIG. 6B, the horizontal sides 61 and 62 of the image 60 on the screen SC change as indicated by broken lines, and the distortion is corrected.

A2-2-2. Projective transformation:
The correspondence between the pixels on the liquid crystal light valve 300 and the pixels on the screen SC in the angle designation correction method of the embodiment will be described. As described above, when image data is corrected in consideration of multi-axis rotation, the result of the corrected image data differs depending on the rotation order. In the embodiment, the projector is rotated in the order of pitch θ → yaw φ → roll ψ. This is because if the pitch θ and yaw φ are fixed, the correction shape is not affected even if the screen is rotated in the roll ψ direction later.

  When the projector is rotated in the order of pitch θ → yaw φ → roll ψ, the point on the screen SC is coordinate-transformed by the projective transformation Φ expressed by the following Equation 3. On the screen, it is represented by the xyz standard coordinate system, (x, y, z) represents a point on the screen, and (x ′, y ′, z ′) represents a coordinate after transformation by the projective transformation Φ. . Z is a constant representing the distance between the projector and the screen.

  As shown in Expression 4, by dividing (x ′, y ′, z ′) after conversion by the z component, the coordinates on the virtual liquid crystal light valve represented by the two-dimensional XY coordinate system ( X, Y).

  The angle designation correction module 434 uses the angle parameters input from the user, Expressions 3 to 4, and uses a distortion image corresponding to the target pixel of the image represented by the input image data (an image formed on the liquid crystal light valve 300). Pixels in the shape) are determined, and the pixel value of the target pixel is assigned to the determined corresponding pixel.

A3. Switching control process:
Switching control processing according to the embodiment will be described with reference to FIGS. FIG. 7 is a flowchart illustrating the switching control process in the embodiment. FIG. 8 is an explanatory diagram illustrating switching control from the four corner designation correction method to the angle designation correction method in the embodiment. The switching control process is executed by the CPU 400 by controlling each module of the distortion correction unit 430. Hereinafter, for convenience of explanation, the description will be made assuming that each module of the distortion correction unit 430 is executed. The switching control process is executed in response to a switching instruction to the angle designation correction method input by the user during the correction process using the four corner designation correction method.

  When the switching control module 438 receives an instruction to switch to the angle designation correction method during the correction by the four corner designation correction method (step S10), the switching control module 438 determines from the coordinate positions of the four corners of the distorted image formed on the liquid crystal light valve 300. Then, a correction angle is calculated when a distortion image having substantially the same shape as the distortion image is formed using the angle designation correction method (step S12).

  The calculation of the correction angle will be described in detail with reference to FIG. In FIG. 8, a point on the liquid crystal light valve 300 is represented by a virtual liquid crystal light valve space defined by a two-dimensional XY standard coordinate system. The distorted image 30 represents the shape of the distorted image after correction by the four-corner designation method.

  The switching control module 438 calculates the upper side S1... From the positions of the coordinates Pv1, Pv2, Pv3, and Pv4 of the four corners of the distorted image 30. The straight lines of the lower side S2, the right side S3 and the left side S4 are obtained, and the intersection H (Hx, Hy) between the upper side S1 and the lower side S2 and the intersection V (Vx, Vy) between the right side S3 and the left side S4 are obtained. Since the intersection point H (Hx, Hy) and the intersection point V (Vx, Vy) on the virtual liquid crystal light valve correspond to the coordinates after the projective transformation of the horizontal vanishing point and the vertical vanishing point in the xyz coordinate system, the horizontal vanishing point H after the conversion '(Hx', Hy ', Hz') and vertical vanishing point V '(Vx', Vy ', Vz') are applied to Equation 4 and expressed as Equation 5. Hereinafter, in the embodiment, the intersection H (Hx, Hy) and the intersection V (Vx, Vy) are also referred to as a horizontal vanishing point H (Hx, Hy) and a vertical vanishing point V (Vx, Vy).

  The horizontal vanishing point H ′ (Hx ′, Hy ′, Hz ′) and the vertical vanishing point V ′ (Vx ′, Vy ′, Vz ′) are the horizontal infinity point and the vertical infinity point in the xyz coordinate system. This is the coordinate after projective transformation. Here, the infinity point can be expressed as a horizontal infinity point = [1: 0: 0] using a homogeneous coordinate, and a vertical infinity point = [0: 1: 0]. Can be represented. The homogeneous coordinates indicate coordinates where the relationship of x: y: z = x ′: y ′: z ′ is established, and (x, y, z) = [x ′: y ′: z ′. ]It can be expressed as.

  When projective transformation is performed using the equation 3 with the horizontal infinity point = [1: 0: 0] and the vertical infinity point = [0: 1: 0], the transformed coordinates are in the xyz coordinate system. The horizontal vanishing point H ′ and the vertical vanishing point V ′ are obtained. Therefore, the horizontal vanishing point H ′ and the vertical vanishing point V ′ are expressed as shown in Expression 6.

  When the three-dimensional coordinates shown in Equation 6 are reduced by the Z component and expressed in a two-dimensional standard coordinate system, the horizontal vanishing point H (Hx, Hy) and the vertical vanishing point on the virtual light valve are obtained as shown in Equation 7. A point V (Vx, Vy) is obtained.

  In addition, each component of the horizontal vanishing point H ′ (Hx ′, Hy ′, Hz ′) and the vertical vanishing point V ′ (Vx ′, Vy ′, Vz ′) in the xyz coordinate system is expressed by Equations 5 and 7. The relationship of the following formula 8 is established.

  From Equation 5 and Equation 8, the values of Vz ′ and Hz ′ are calculated as shown in Equation 9 below. Vz 'and Hz' correspond to "intermediate values" in the claims. Note that sgn (A) represents the sign (± 1) of the value A in parentheses.

  The correction angles θ, φ, and ψ are calculated as shown in Expression 10 using Expression 7 and Expression 9.

  The switching control module 438 sets the calculated correction angles θ, φ, ψ as angle parameters (step S14). The CPU 400 controls the angle designation correction module 434 to generate corrected image data using the angle parameter set to the correction angle (step S16), and inputs the generated corrected image data to the liquid crystal light valve 300. (Step S18). The liquid crystal light valve 300 is formed with a distortion image 30 having substantially the same shape before and after switching from the four-corner designation correction method to the angle designation correction method. The screen SC also has an image 40 having substantially the same shape before and after switching. It is displayed.

  When the switching control process ends, the CPU 400 displays the angle parameter correction screen WD, and corrects the distortion of the image displayed on the screen using the angle designation correction method according to the input from the user.

  By the way, in the embodiment, when the angle designation correction method has never been executed, the angle parameters of the projector are set to angles θ = 0, φ = 0, and ψ = 0. When an instruction for switching from the four corner designation correction method to the angle designation correction method is received, if a distortion image is formed by the angle designation correction method using the angles θ = 0, φ = 0, and ψ = 0, as shown in FIG. A rectangular image 35 without distortion is formed on the light valve 300. Since the shape of the image 35 is different from that of the distorted image 30, an image having a different shape is displayed on the screen before and after switching. That is, the correction by the four corner designation correction method is not carried over and the image is displayed in the shape before the correction by the four corner designation correction method. However, according to the projector PJ of the present embodiment, the image corrected by using the four corner designation correction method is displayed. From this shape, it is possible to continue correction using an angle designation correction method.

  According to the projector of the embodiment described above, the change amount of the angle parameter corresponding to the correction by the four corner designation correction method is reflected before and after switching from the four corner designation correction method to the angle designation correction method. The correction by the angle designation correction method can be executed while maintaining the shape of the image displayed on the screen after the correction by. That is, the correction by the angle designation correction method can be started from the continuation of the correction by the four corner designation correction method. Therefore, when the user switches from the four corner designation correction method to the angle designation correction method, the user does not need to correct again from the state before the correction by the four corner designation correction method, so that the convenience of the user can be improved.

  Further, according to the projector of the embodiment, the correction angle using the position of the vanishing point of the distorted image formed on the liquid crystal light valve so that the inclination of the side of the distorted image on the liquid crystal light valve does not change before and after switching. Is calculated. Therefore, the inclination of the sides of the image shape displayed on the screen before and after switching can be substantially maintained. Therefore, the user can smoothly switch the correction method in appearance.

B. Variations:
(1) In the embodiment, the projector PJ includes a distortion correction unit, and corresponds to the image processing device and the projector according to the present invention. However, for example, the distortion correction unit may be provided in a personal computer different from the projector. In such a case, the computer corresponds to the image processing apparatus according to the present invention.

(2) In the embodiment, the projector includes a liquid crystal light valve. For example, instead of the liquid crystal light valve, a micromirror light modulator such as DMD (Digital Micromirror Device) (registered trademark of TI) is used. You may prepare. Alternatively, the projector may include a high-intensity cathode ray tube, a plasma display panel, an electroluminescence display panel, a light emitting diode display panel, a field emission display panel, and the like. Thus, as the image forming unit, a non-self-luminous device or a self-luminous device can be used.

(3) In the embodiment, a part of the configuration realized by hardware may be replaced by software, and conversely, a part of the configuration realized by software may be replaced by hardware. Good.

  As mentioned above, although the various Example of this invention was described, this invention is not limited to these Examples, A various structure can be taken in the range which does not deviate from the meaning.

FIG. 2 is a block diagram illustrating a configuration of a projector in the embodiment. Explanatory drawing explaining the four corner designation | designated correction system in an Example. Explanatory drawing which illustrates the operation part in an Example. Explanatory drawing explaining the angle (projection angle) between the projector and screen SC in an Example in an Example. Explanatory drawing which illustrates angle parameter correction screen WD in an example. Explanatory drawing explaining the angle correction designation | designated system in an Example. The flowchart explaining the switching control process in an Example. Explanatory drawing explaining switching control from the four corner designation | designated correction system to an angle designation correction system in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 30 ... Distorted image 35 ... Image 40 ... Image 100 ... Illumination optical system 110 ... Light source lamp drive part 300 ... Liquid crystal light valve 310 ... Liquid crystal light valve drive part 340 ... Projection optical system 350 ... Projection optical system adjustment part 400 ... CPU
DESCRIPTION OF SYMBOLS 410 ... Image input part 420 ... Image processing part 430 ... Distortion correction part 432 ... Four corner designation | designated correction module 434 ... Angle designation correction module 438 ... Switching control module 510 ... Operation part

Claims (10)

An image processing apparatus used in a projector including an image forming unit that forms an image to be displayed on a projection surface using image data,
First corrected image data for generating first corrected image data in which distortion of the display image is corrected from original image data in accordance with a change in the correction point displayed on the display image projected on the projection plane Generating means;
Second corrected image data generating means for generating second corrected image data in which distortion of the display image is corrected from the original image data in accordance with a change in an angle parameter relating to a projection angle of the projector;
When the first corrected image data generating unit is switched to the second corrected image data generating unit, the shape of the first distorted image formed in the image forming unit using the first corrected image data is related. Based on shape information, an initial value for generating an initial value of the angle parameter such that the shape of the image represented by the image data generated by the second corrected image data is substantially the same shape as the first distortion image and a generation means,
The second corrected image data generation unit generates the second corrected image data using the generated initial value when the initial value is generated. The image processing apparatus according to claim 1, further comprising:
A switching means for switching image data generating means to be output to the image forming unit between the first corrected image data generating means and the second corrected image data generating means;
The initial value generating means generates the initial value at the time of switching from the first corrected image data generating means to the second corrected image data generating means,
The second corrected image data generating means generates the second corrected image data using the initial value at the time of switching. The image processing apparatus according to claim 1 or 2,
The shape of the first distortion image includes a quadrangle,
The initial value generating means includes
Acquisition means for acquiring position information regarding the positions of the four corners of the first distortion image as the shape information;
An image processing apparatus comprising: a calculation unit that calculates the initial value using the acquired position information. The image processing apparatus according to claim 3,
The calculating means is configured so that an inclination of an edge of an image represented by the second image data generated using the initial value is substantially the same as an inclination of an edge of the first distortion image. An image processing apparatus for calculating an initial value. The image processing apparatus according to claim 4,
The calculating means is configured so that the position of the vanishing point of the image is substantially the same as the position of the vanishing point of the first distorted image by the second corrected image data generated using the initial value. An image processing apparatus for calculating an initial value. The image processing apparatus according to claim 5, wherein
The calculation means includes vertical vanishing point position information (Vx, Vy) representing the position of the vanishing point in the vertical direction of the first distorted image defined by the shape information and horizontal vanishing point representing the position of the vanishing point in the horizontal direction. Point information (Hx, Hy) is applied to Equation 1, intermediate values Vz ′ and Hz ′ for calculating the initial values (ψ, θ, φ) are calculated, and the intermediate values are applied to Equation 2. And calculating the initial values (ψ, θ, φ).

A projector,
An image processing apparatus according to any one of claims 1 to 6,
A light source;
An image forming unit that forms an image to be displayed on the projection plane by using the first corrected image data or the second corrected image data input from the image processing apparatus and the light emitted from the light source. When,
The projector comprising: a projection optical system that projects the emitted light output from the image forming unit onto a projection surface. An image processing method executed by an image processing apparatus used in a projector including an image forming unit that emits image light representing the image according to original image data representing the image,
A first corrected image in which distortion of the display image is corrected from the original image data in accordance with a change of the correction point displayed on the display image projected on the projection plane by the first corrected image data generation unit. Generate data,
The second corrected image data generating means generates second corrected image data in which distortion of the display image is corrected from the original image data in accordance with a change in the angle parameter relating to the projection angle of the projector,
When the first corrected image data generating unit is switched to the second corrected image data generating unit, the shape of the first distorted image formed in the image forming unit using the first corrected image data is related. Generating an initial value of the angle parameter based on shape information so that the shape of the image represented by the second corrected image data has substantially the same shape as the first distortion image.
An image processing method for generating the second corrected image data using the generated initial value in generating the second corrected image data. A computer program for causing an image processing apparatus used in a projector including an image forming unit to emit image light representing the image according to original image data representing the image to perform image processing,
A function of generating first corrected image data in which distortion of the display image is corrected from original image data in accordance with a change of a correction point displayed on the display image projected on the projection plane;
A function of generating second corrected image data in which distortion of the display image is corrected from the original image data in accordance with a change in an angle parameter relating to a projection angle of the projector;
When the function of generating the first corrected image data is switched to the function of generating the second corrected image data, the first distortion formed in the image forming unit using the first corrected image data based on the shape on the shape information of the image, the shape of the image is represented by a second corrected image data, a function of generating an initial value of the angle parameter to be substantially the same shape as the first distorted image, the A computer program for causing an image processing device to execute,
The function of generating the second corrected image data is a computer program that generates the second corrected image data by using the generated initial value.   A recording medium recording the computer program according to claim 9 in a computer-readable manner.

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