JP2013025076A - Image processor, image display device and image processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor capable of enhancing image quality of an image displayed by tiling display, and further to provide an image processing method or the like.SOLUTION: An image processing section 100 for performing unevenness correction of a tiling image in which a first projection image IMG1 and a second projection image IMG2 provided with a superimposed region are disposed includes: a first unevenness correction LUT storage section 160 that stores a correction value for correcting unevenness of the first projection image IMG1; a first unevenness correction processing section 162 for correcting the unevenness of the first projection image IMG1 by using the correction value. Luminance of a boundary position B1 in a boundary portion between a non-superimposed region and a superimposed region of the first projection image IMG1 is lower than luminance of a boundary position B2 in a boundary portion between a non-superimposed region and a superimposed region of the second projection image IMG2. In the non-superimposed region and the superimposed region of the first projection image IMG1, the first unevenness correction processing section 162 corrects the unevenness thereof on the basis of the luminance of the boundary position B2.

Description

  The present invention relates to an image processing device, an image display device, an image processing method, and the like.

  A tiling (multi-projection) technology is known that uses a plurality of projectors (image display devices) to superimpose and display a portion of the projected image projected by each projector, thereby improving the resolution and resolution. ing. In this tiling technique, it is conceivable to combine projectors of different models as well as combinations of projectors of the same model (same type, same model number).

  On the other hand, brightness unevenness and color unevenness (unevenness in a broad sense) are a barrier to high image quality in projectors, and brightness unevenness correction and color unevenness correction corresponding to the display characteristics are performed for each projector. When tiling display is performed using such a projector, brightness unevenness correction and color unevenness correction are performed in consideration of display by only one projector, and the brightness gradually decreases from the center of the screen toward the periphery. However, it is desirable that the color be uniform within the screen.

  By the way, when performing tiling display, a part of the projection image of each projector in the vertical direction (vertical direction) or the horizontal direction (horizontal direction) is overlapped with the adjacent projection image, and the superimposition region has a change in luminance or color. In many cases, a gentle blend process is performed. Alternatively, in addition to hardware light amount adjustment by the light shielding plate, blending processing by software may be performed.

  FIG. 21A shows an explanatory diagram of tiling display. FIG. 21B is an explanatory diagram of a blend process performed on an image displayed as tiled as shown in FIG. FIG. 21A and FIG. 21B illustrate an example of a change in luminance in the horizontal direction in an image displayed by tiling using two projectors. In FIG. 21B, a change in luminance in the horizontal direction of each projection image after blend processing is represented by a wavy line, and a change in luminance in the horizontal direction of a tiling-displayed image is represented by a solid line.

  When performing tiling display, an overlapping region is provided on the projection surface, and the projection image IMG1 from the first projector is superimposed on the projection image IMG2 from the second projector. At this time, luminance unevenness correction and color unevenness correction unique to each projector are performed, and the projected images IMG1 and IMG2 gradually decrease in luminance from the center to the periphery as shown in FIG. , The color is made uniform in the screen. As a result, as shown in FIG. 21B, the blending process corrects the luminance and color changes of the superimposed regions of the projection images IMG1 and IMG2 to be gentle, and improves the image quality of the tiled display image. Can be achieved.

  Various techniques for improving the image quality of such tiling-displayed images have been proposed. For example, Patent Literature 1 discloses a technique for making an image of a tiled display inconspicuous by capturing a tiling-displayed image and correcting the image so as to obtain uniform or continuous brightness over the entire display area.

JP 2002-116500 A

  However, each projector has a difference in luminance and chromaticity, and unique peripheral dimming characteristics. For this reason, with the technique disclosed in Patent Document 1, it is difficult to gently change the entire screen with a single projector even if blend processing is performed as shown in FIG. Therefore, in the tiling-displayed image, there remains a problem that changes in luminance and color are undulated in the superimposition region and are recognized as unevenness by the human eye observing the image.

  In particular, in each projector, the white color is not adjusted to a standard value such as sRGB (standard RGB), but the original white color (device white) of the projector is used as it is, or a color between device white and sRGB is used. Doing so often ensures brightness. Therefore, the greater the individual difference between projectors, the more severe the change in the overlapping area. In addition, if white is completely adjusted to the standard value in each projector for tiling display, or if unevenness correction is performed so that the luminance is uniform in the screen, luminance loss increases, which is not desirable.

  The present invention has been made in view of the above technical problems. According to some aspects of the present invention, it is possible to improve the image quality of a tiling-displayed image by performing correction so as to reduce the change in the overlapping region according to the display characteristics of each image display device. An image processing apparatus, an image display apparatus, an image processing method, and the like that can be provided can be provided.

  (1) In the first aspect of the present invention, an image processing apparatus that performs uneven correction of a tiling image in which a first projection image and a second projection image are arranged with an overlapping region is provided. A first unevenness correction value storage unit that stores a correction value for correcting unevenness of the image, and a first unevenness correction that corrects unevenness of the first projection image using the correction value stored in the first unevenness correction storage unit. A luminance of a first pixel position at a boundary portion between the non-overlapping area of the first projection image and the superimposing area, and a luminance between the non-overlapping area of the second projection image and the overlapping area. The first unevenness correction processing unit is lower than the luminance of the second pixel position in the boundary portion, and the first unevenness correction processing unit performs unevenness based on the luminance of the second pixel position in the non-overlapping region and the overlapping region of the first projection image. Correct.

  In this aspect, a tiling image is displayed by the first projection image and the second projection image. At this time, the first pixel position at the boundary between the non-overlapping area and the overlapping area of the first projection image is the second pixel position at the boundary between the non-overlapping area and the overlapping area of the second projection image. Lower than brightness. Therefore, the first unevenness correction processing unit performs unevenness correction processing based on the luminance at the second pixel position in the non-overlapping area and the overlapping area of the first projection image with low luminance at the first pixel position. Thereby, it can correct | amend so that the change in a superimposition area | region may become small according to the display characteristic of the image display apparatus which displays each of a 1st projection image and a 2nd projection image, and the image displayed by tiling Image quality can be improved.

(2) In the image processing apparatus according to the second aspect of the present invention, in the first aspect, the first unevenness correction processing unit corresponds to the luminance of the second pixel position in the first projection image. The unevenness is corrected from the third pixel position in the non-superimposed region in the first projection image having luminance to the first projected image end in the superimposed region.
In this aspect, in the first projection image, the unevenness is corrected from the third pixel position in the non-overlapping area in the first projection image having the luminance corresponding to the luminance of the second pixel position to the overlapping area. Therefore, unevenness such as a valley of brightness in the overlapping region can be reduced.

(3) In the image processing apparatus according to the third aspect of the present invention, in the second aspect, the first unevenness correction processing unit is configured so that the color difference with reference to the third pixel position is minimized. Correct unevenness.
According to this aspect, since the unevenness is corrected so that the color difference based on the third pixel position is minimized, the color change in the region where the unevenness is corrected is reduced, and the tiling display is performed. It is possible to improve the quality of the image.

(4) In the image processing device according to the fourth aspect of the present invention, in any one of the first aspect to the third aspect, a second value that stores a correction value for correcting the unevenness of the second projected image is stored. A non-uniformity correction value storage unit, and a second non-uniformity correction processing unit that corrects non-uniformity of the second projected image using the correction value stored in the second non-uniformity correction storage unit. Corrects unevenness so that the color difference between the first pixel position corrected by the first unevenness correction processing unit and the luminance peak position in the second projected image is minimized.
In this aspect, paying attention to the color difference between the first pixel position corrected by the first unevenness correction processing unit and the luminance peak position in the second projection image, the first projection image and the second projection Unevenness is corrected for each of the images. By doing so, it is possible to smoothen the luminance change and the color change in the overlapping region of both projection images displayed on the tiling, and to improve the image quality of the image displayed on the tiling.

(5) In the image processing apparatus according to the fifth aspect of the present invention, in the first aspect or the second aspect, a second unevenness correction value that stores a correction value for correcting the unevenness of the second projection image. A storage unit, and a second unevenness correction processing unit that corrects the unevenness of the second projected image using the correction value stored in the second unevenness correction storage unit, the first unevenness correction processing unit and the first unevenness correction processing unit The second unevenness correction processing unit includes a first color difference between a luminance peak position in the first projection image and the first pixel position corrected by the first unevenness correction processing unit, and the first unevenness correction. The unevenness is corrected so that the sum of the first color position after the correction by the processing unit and the second color difference between the luminance peak positions in the second projection image is minimized.
In this aspect, the first color difference between the luminance peak position in the first projection image and the first pixel position after correction by the first unevenness correction processing unit, and after correction by the first unevenness correction processing unit Focusing on the sum of the first pixel position and the second color difference between the luminance peak positions in the second projection image, the unevenness of each of the first projection image and the second projection image is corrected. By doing so, it is possible to smoothen the luminance change and the color change in the overlapping region of both projection images displayed on the tiling, and to improve the image quality of the image displayed on the tiling.

(6) In the image processing apparatus according to the sixth aspect of the present invention, in the first aspect or the second aspect, a second unevenness correction value that stores a correction value for correcting the unevenness of the second projection image. A storage unit, and a second unevenness correction processing unit that corrects the unevenness of the second projected image using the correction value stored in the second unevenness correction storage unit, the first unevenness correction processing unit and the first unevenness correction processing unit The non-uniformity correction processing unit 2 corrects the non-uniformity so that the change in brightness is monotonous between the luminance peak position in the first projection image and the luminance peak position in the second projection image. To do.
In this aspect, the first projection image and the first projection image are changed so that the change in brightness is monotonous between the luminance peak position in the first projection image and the luminance peak position in the second projection image. The unevenness is corrected for each of the two projected images. By doing so, it is possible to smoothen the luminance change and the color change in the overlapping region of both projection images displayed on the tiling, and to improve the image quality of the image displayed on the tiling.

  (7) In a seventh aspect of the present invention, the image display device includes the image processing device according to any one of the first to sixth aspects.

  According to this aspect, it is possible to provide an image display device that improves the image quality of a tiling-displayed image by performing correction so as to reduce the change in the superimposed region according to the display characteristics. .

  (8) According to an eighth aspect of the present invention, there is provided an image processing method for correcting unevenness of a tiling image in which a first projection image and a second projection image are arranged with a superimposed region, the first projection image The luminance of the first pixel position at the boundary between the non-overlapping area and the overlapping area is the luminance of the second pixel position at the boundary between the non-superimposing area and the overlapping area in the second projection image. The unevenness is corrected in the non-overlapping area and the overlapping area of the first projection image based on the lower brightness of the second pixel position.

  In this aspect, when the tiling image is displayed by the first projection image and the second projection image, the first pixel position at the boundary between the non-overlapping area and the overlapping area of the first projection image is It is lower than the brightness of the second pixel position at the boundary between the non-overlapping area and the overlapping area of the two projection images. At this time, since the unevenness correction processing is performed based on the luminance at the second pixel position in the non-superimposed region and the superimposed region of the first projection image with low luminance at the first pixel position, the first projection It can correct | amend so that the change in a superimposition area | region may become small according to the display characteristic of the image display apparatus which displays each of an image and a 2nd projection image. Therefore, it is possible to provide an image processing method that improves the image quality of the tiling-displayed image.

1 is a block diagram of a configuration example of a multi-projection system according to a first embodiment. The block diagram of the structural example of the image process part of FIG. FIG. 3 is a flowchart of a processing example of an image processing unit in FIG. 2. The flowchart of an example of the preparation process of nonuniformity correction LUT. The flowchart of an example of a nonuniformity correction LUT creation process. The flowchart of an example of a nonuniformity characteristic measurement process. The flowchart of an example of a nonuniformity correction | amendment LUT production | generation process. FIG. 6 is a flowchart of an example of unevenness correction target value calculation processing in step S42 of FIG. Explanatory drawing of the 1st projection image and 2nd projection image which are tiling-displayed in 1st Embodiment. FIG. 10 is a diagram illustrating an example of a color gamut of the first projector and the second projector illustrated in FIG. 9. FIG. 5 is a first explanatory diagram regarding unevenness correction processing in the first embodiment. FIG. 6 is a second explanatory diagram relating to unevenness correction processing in the first embodiment. Explanatory drawing of the boundary position of the superimposition area | region in 1st Embodiment. FIG. 6 is a third explanatory diagram regarding unevenness correction processing in the first embodiment. The block diagram of the structural example of the multi-projection system in 2nd Embodiment. FIG. 16 is a block diagram of a configuration example of the image processing apparatus in FIG. 15. The 1st explanatory view about the unevenness correction processing in a 2nd embodiment. FIG. 10 is a second explanatory diagram relating to unevenness correction processing in the second embodiment. Explanatory drawing regarding the nonuniformity correction process in the 1st modification of 2nd Embodiment. Explanatory drawing regarding the nonuniformity correction process in the 2nd modification of 2nd Embodiment. FIG. 21A is an explanatory diagram of tiling display. FIG. 21B is an explanatory diagram of a blend process performed on an image displayed as tiled as shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, all of the configurations described below are not necessarily indispensable configuration requirements for solving the problems of the present invention.
In the following embodiment, an example in which tiling display is performed using two projectors will be described. However, the present invention can also be applied to a case where tiling display is performed using three or more projectors. . In the following, an example in which tiling display is arranged in the horizontal direction using two projectors will be described. However, the present invention can be similarly applied to the case where tiling display is arranged in the vertical direction.

[First Embodiment]
FIG. 1 is a block diagram showing a configuration example of a multi-projection system according to the first embodiment of the present invention. In FIG. 1, the first projector (first image display device) constituting the multi-projection system includes an image processing unit as the image processing device in the first embodiment. The first projector becomes the master, and the second projector (second image display device) is connected to the first projector as a slave.

  The multi-projection system (display system in a broad sense) 10 includes a first projector PJ1, a second projector PJ2, an image signal supply device 20, and an unevenness measuring device 30. The first projector PJ1 includes an image processing unit 100, an image forming unit 200, and an operation unit 300. The second projector PJ2 also includes an image forming unit (not shown) similar to the image forming unit 200 of the first projector PJ1.

  Each of the first projector PJ1 and the second projector PJ2 displays a projected image on the screen SCR by providing a superimposed region based on the image signal from the image signal supply device 20, thereby displaying a tiling image. indicate. At this time, the first projector PJ1 performs the unevenness correction process based on the unevenness measurement result of the projection image on the screen SCR measured by the unevenness measuring device 30, and the first projection based on the image signal after the unevenness correction process. The image IMG1 is projected on the screen SCR. By performing tiling display with the first projection image IMG1 and the second projection image IMG2, a tiling image in which the luminance change and color change in the superimposed region are small and the image quality is improved is displayed.

  The image signal supply device 20 generates an image signal corresponding to an image to be tiled and supplies the image signal to the first projector PJ1. An image signal is supplied to the second projector PJ2 from the first projector PJ1 provided as a master. Further, the image signal supply device 20 supplies an image signal corresponding to an unevenness measurement pattern for performing unevenness correction processing such as uneven brightness correction and uneven color correction to the first projector PJ1. Such a function of the image signal supply device 20 is realized by a DVD (Digital Versatile Disc) device, a personal computer (PC), or the like. Note that the image processing unit 100 may have some or all of the functions of the image signal supply device 20.

  The unevenness measuring device 30 is a two-dimensional image sensor such as a CCD (Charge Coupled Device) sensor and is installed so that an image projected on the screen SCR can be measured (captured). The unevenness measuring device 30 captures a solid image displayed based on the image signal of each unevenness measurement pattern from the image signal supply device 20, and acquires two-dimensional distribution information of XYZ tristimulus values in the plane. The unevenness measurement pattern can be a gray image and a solid image (an image having all the same pixel values) including a halftone in which the gradation of each color component of RGB is changed from 0 percent to 100 percent. As such an unevenness measuring device 30, for example, there is an apparatus (for example, ProMetric of Radiant Imaging) that takes an image using a filter having a spectral sensitivity approximated by an xyz color matching function and obtains XYZ tristimulus values by matrix correction calculation. . Data captured by the unevenness measuring device 30 is sent to the image processing unit 100 as an unevenness measurement value. The image processing unit 100 may incorporate a control unit for controlling the unevenness measurement process performed by the unevenness measuring device 30.

  The image processing unit 100 performs unevenness correction processing on the image signal from the image signal supply device 20 according to the resolution type of the image for single display or tiling display and the color characteristic (display characteristic) of each projector. The image correction process is performed, and the image signal after the image correction process is supplied to each image forming unit. Such a function of the image processing unit 100 is realized by a software process realized by a configuration having a central processing unit (CPU) and a memory, and a logic circuit such as an ASIC (Application Specific Integrated Circuit). .

  The image forming unit 200 includes a light source, an optical system (illumination optical system) that sends light from the light source to a light valve (light modulation unit), a dichroic mirror, a liquid crystal light valve, a color synthesis prism (cross dichroic prism), a projection optical system, Including a drive circuit and the like. The image forming unit 200 modulates the light from the light source based on the image signal from the image processing unit 100 to form an image, and projects the image on the screen SCR.

  The operation unit 300 is input with operation information for setting the display mode such as single display and tiling display, setting the position of each projector at the time of tiling display, and the size and position of the overlapping area by the user. The The image processing unit 100 includes a plurality of unevenness correction processing modes, and the operation unit 300 has operation information for selecting an unevenness correction lookup table (LUT) used in the unevenness correction processing. Entered. These pieces of operation information are sent to the image processing unit 100.

  FIG. 2 is a block diagram showing a configuration example of the image processing unit 100 shown in FIG. 2, the image signal supply device 20, the unevenness measurement device 30, the image forming unit 200, the operation unit 300, and the second projector PJ2 of FIG. 1 are also illustrated for convenience of explanation.

  The image processing unit 100 includes an image division processing unit 110, an unevenness correction LUT selection unit 120, an unevenness correction target value calculation unit 130, an unevenness correction LUT generation unit 140, and a notification processing unit 150. Further, the image processing unit 100 corresponds to the image forming unit 200 of the first projector PJ1, and includes a first unevenness correction LUT storage unit (first unevenness correction value storage unit) 160, a first unevenness correction processing unit 162, and the like. It has.

The image division processing unit 110 performs image division processing on the image signal from the image signal supply device 20 in accordance with the setting content of the overlapping area set by the operation unit 300. The image signal after the division process is output to the first unevenness correction processing unit 162 and the second projector PJ2.
The unevenness correction LUT selection unit 120 selects one of a plurality of unevenness correction LUTs stored in the first unevenness correction LUT storage unit 160. The unevenness correction LUT selection unit 120 selects an unevenness correction LUT according to the type (single display or tiling display) of the image signal from the image signal supply device 20 and the arrangement of the projector, or the operation information from the operation unit 300. Based on this, the unevenness correction LUT is selected. In addition, the unevenness correction LUT selection unit 120 may select the unevenness correction LUT based on information included in the image signal itself from the image signal supply device 20 or an analysis result of the input image.

The unevenness correction target value calculation unit 130 calculates the target value of the unevenness correction processing of the image signal based on the unevenness measurement value of the projection image of each projector measured by the unevenness measurement device 30. At this time, the nonuniformity correction target value calculation unit 130 calculates the nonuniformity correction target value in at least a part of the superimposition region and the non-superimposition region of the first projection image IMG1 according to the setting content of the superposition region set by the operation unit 300. To do.
The unevenness correction LUT generation unit 140 generates an unevenness correction LUT in which unevenness correction values for performing unevenness correction processing in the first projector PJ1 are tabulated based on the unevenness correction target value calculated by the unevenness correction target value calculation unit 130. .
The first unevenness correction LUT storage unit 160 stores the unevenness correction LUT generated by the unevenness correction LUT generation unit 140. Such a first unevenness correction LUT storage unit 160 includes a memory such as an SRAM (Static Random Access Memory) and a control unit that performs write control and read control on the memory.

  The notification processing unit 150 performs a given notification process based on the calculation result in the unevenness correction target value calculation unit 130. For example, when it is determined that the image quality of the tiling image cannot be improved even if the first unevenness correction process is performed in the calculation process in the unevenness correction target value calculation unit 130, the notification processing unit 150 changes the display condition of the tiling image. A process for displaying a screen prompting the user is performed. Specifically, the notification processing unit 150 performs processing for displaying on the screen SCR a screen that prompts resetting of the overlapping area. For example, when the change in luminance or color difference after the first unevenness correction processing is equal to or greater than a given threshold, the notification processing unit 150 can determine that the image quality of the tiling image cannot be improved.

  The first unevenness correction processing unit 162 performs unevenness correction processing using the unevenness correction LUT stored in the first unevenness correction LUT storage unit 160. In order to reduce the storage capacity, the first unevenness correction LUT storage unit 160 has corresponding unevenness correction values at a given number of lattice points in the three axes of the vertical direction of the screen × the horizontal direction of the screen × the gradation direction. Stored as LUT. Therefore, the first unevenness correction processing unit 162 obtains the unevenness correction value between the lattice points from the unevenness correction value at the lattice point by a known interpolation operation such as linear interpolation or curve interpolation, and uses the unevenness correction value to perform the unevenness correction processing. The image signal is obtained.

[Unevenness correction processing]
Next, the unevenness correction processing by the image processing unit 100 in FIG. 2 will be described in detail.
FIG. 3 shows a flowchart of a processing example of the image processing unit 100 in FIG.
First, the image processing unit 100 selects one unevenness correction LUT by the unevenness correction LUT selection unit 120 from among the plurality of unevenness correction LUTs stored in the first unevenness correction LUT storage unit 160 (step S10). At this time, the unevenness correction LUT selection unit 120 selects the unevenness correction LUT based on the image signal from the image signal supply device 20 or the operation information from the operation unit 300. The first unevenness correction LUT storage unit 160 stores a single display, tiling display, and a plurality of unevenness correction LUTs according to the arrangement of the projectors.

  The image processing unit 100 monitors the input of the image signal from the image signal supply device 20 in the image division processing unit 110 (step S12: N), and when the image signal is input (step S12: Y), the image processing unit 100 monitors the image. The division process is performed. The image division processing unit 110 performs image division processing according to the setting content of the overlapping area set by the operation unit 300. The image signal of the image projected from the first projector PJ1 among the images after the division processing is output to the first unevenness correction processing unit 162, and the image signal of the image projected by the second projector PJ2 is the second image signal. Is output to the projector PJ2.

Next, in the first unevenness correction processing unit 162, the image processing unit 100 reads the unevenness correction value from the first unevenness correction LUT storage unit 160 (step S14). Then, for the image signal from the image division processing unit 110, the first unevenness correction processing unit 162 calculates a known interpolation operation such as linear interpolation or curve interpolation from the unevenness correction value at the lattice point stored in the unevenness correction LUT. Thus, the unevenness correction value between the lattice points is calculated (step S16). Thereafter, the first unevenness correction processing unit 162 performs unevenness correction processing on the image signal using the unevenness correction value at the lattice points stored in the unevenness correction LUT or the unevenness correction value between the lattice points obtained in step S16. This is performed (step S18).
When the input of the image signal is finished (step S20: Y), the image processing unit 100 finishes a series of processing (end), and when the input of the image signal is not finished (step S20: N), the image processing unit 100. Returns to step S12.

The correction LUT used for the unevenness correction process is generated by the following procedure and stored in the first unevenness correction LUT storage unit 160.
FIG. 4 shows a flowchart of an example of the unevenness correction LUT preparation process. The unevenness correction LUT preparation process shown in FIG. 4 is performed prior to the unevenness correction processing by the first unevenness correction processing unit 162.
First, the image processing unit 100 performs processing (for example, screen display) that prompts the user to specify a superimposition region via the operation unit 300. When the user operates the operation unit 300 to specify a range of a superimposition region (for example, 25% of each projection image) in each projection image, the image processing unit 100 receives operation information corresponding to the designated superimposition region ( Step S30). Thereafter, the image processing unit 100 performs a process of displaying the superimposed area on the screen SCR as a guide based on the designated superimposed area, and the user installs the first projector PJ1 and the second projector PJ2. It is desirable to be able to adjust the position. At this time, the image processing unit 100 may change the color of the superimposed area on the screen SCR according to the designated superimposed area, or may display the boundary with a line.

Next, the image processing unit 100 sets the unevenness correction processing by the first unevenness correction processing unit 162 to OFF (step S32). Thereby, the color characteristics of each of the first projector PJ1 and the second projector PJ2 can be measured.
Thereafter, the image processing unit 100 performs unevenness correction LUT creation processing in the unevenness correction LUT generation unit 140 and the like (step S34). In step S34, the unevenness correction target value is calculated based on the unevenness measurement values of the first projector PJ1 and the second projector PJ2 measured by the unevenness measurement device 30, and the unevenness correction LUT is generated based on the unevenness correction target value. The Then, the unevenness correction LUT is stored in the first unevenness correction LUT storage unit 160.

  Finally, the image processing unit 100 turns on the unevenness correction processing by the first unevenness correction processing unit 162 (step S36), and ends the series of processing (end). Thereafter, the image processing unit 100 can start the unevenness correction process using the unevenness correction LUT stored in the first unevenness correction LUT storage unit 160 in step S34.

FIG. 5 shows a flowchart of an example of the unevenness correction LUT creation process. The unevenness correction LUT creation process shown in FIG. 5 is performed in step S34 of FIG.
FIG. 6 shows a flowchart of an example of the unevenness characteristic measurement process. The unevenness characteristic measurement process shown in FIG. 6 is performed in step S40 of FIG.
FIG. 7 shows a flowchart of an example of the unevenness correction LUT generation process. The unevenness correction LUT generation process shown in FIG. 7 is performed in step S44 of FIG.

  In the unevenness correction LUT creation process illustrated in FIG. 5, the image processing unit 100 controls the unevenness measuring device 30 to determine the color characteristic values (XYZ values) of the respective RGB gradations of the first projector PJ1 and the second projector PJ2. ) Is obtained as an uneven measurement value (step S40).

  In step S40, as shown in FIG. 6, the image processing unit 100 causes the image forming unit 200 to display a measurement pattern for unevenness correction processing. This measurement pattern uses a solid image of WRGB (gray, red, green, and blue) that is uniform over the entire screen. The image processing unit 100 sequentially switches the display of the measurement pattern of the solid image (step S50). For example, W255 (white, numerical values are gradation values), W224, W192, W160, W128, W96, W64, W32, and W0 (black) are used as the gray solid image. For example, R255 (red), R224,..., R64, R32, G255 (green), G224,..., G64, G32, B255 (blue), B224,.

Next, the image processing unit 100 controls the unevenness measuring device 30 to measure (capture) the measurement pattern displayed on the screen SCR (step S52). The unevenness measuring device 30 may be installed so that all the projected images of the respective projectors are within the shooting screen, and the exposure and focus are not crushed and the unevenness state can be recognized correctly. At this time, it is desirable that the unevenness measuring device 30 is installed on a tripod so that the photographing data of the measurement pattern does not shift. The image processing unit 100 performs one imaging for one measurement pattern (gradation), and acquires the imaging data as an unevenness measuring device.
When all measurements are finished (step S54: Y), the image processing unit 100 finishes a series of uneven characteristic measurement processes (end), and when all measurements are not finished (step S54: N), the process returns to step S50.

  When the unevenness measurement is performed in step S40 of FIG. 5, the image processing unit 100 calculates the unevenness correction target value in the unevenness correction target value calculation unit 130 (step S42, unevenness correction target value calculation step). The unevenness correction target value calculation unit 130 considers the chromaticity of the target color space such as sRGB, and determines the whiteness or gray axis (white to black) of each projector used in the tiling state from the unevenness measurement value of each gradation for each projector. ) Is determined. Details of step S42 will be described later.

  Subsequently, in the unevenness correction LUT generation unit 140, the image processing unit 100 generates an unevenness correction LUT (step S44, unevenness correction LUT generation step). The unevenness correction LUT generation unit 140 generates an LUT by calculating an input RGB value for outputting a target XYZ value using the unevenness measurement value for each projector.

  In step S44, as shown in FIG. 7, the unevenness correction LUT generation unit 140 calculates a color target value corresponding to each grid point input value of the unevenness correction LUT (step S60). Next, the unevenness correction LUT generation unit 140 searches for an input value that can output the calculated color target value from the measured color characteristic values of the projector (step S62). The unevenness correction LUT generation unit 140 stores the result searched in step S62 as an LUT value (step S64). Thereafter, when the search for LUT values for all grid points of the unevenness correction LUT is completed (step S66: Y), the unevenness correction LUT generation unit 140 ends a series of unevenness correction LUT generation processing (end), and the search ends. If not (Step S66: N), the process returns to Step S60.

  When the unevenness correction LUT is generated in step S44 of FIG. 5, the image processing unit 100 stores the generated unevenness correction LUT in the first unevenness correction LUT storage unit 160 (step S46), and performs a series of unevenness correction LUT creation processing. End (end).

Next, the unevenness correction target value calculation process performed in step S42 of FIG. 5 will be described in detail.
FIG. 8 shows a flowchart of an example of the unevenness correction target value calculation process in step S42 of FIG.
First, the unevenness correction target value calculation unit 130 acquires the target color space and the color characteristic value of each projector (step S70). Then, the unevenness correction target value calculation unit 130 calculates the white target value of each projector in the target color space based on the color characteristic value of each projector (projected image of each projector) (step S72). Thereafter, the unevenness correction target value calculation unit 130 calculates the halftone target value of each projector using the white target value of each projector calculated in step S72 (step S74), and ends a series of processing (end). .

Hereinafter, the unevenness correction target value calculation process of FIG. 8 will be described in detail.
FIG. 9 is an explanatory diagram of the first projection image IMG1 and the second projection image IMG2 that are tiling-displayed in the first embodiment. FIG. 9 shows an example of a change in luminance in the horizontal direction in a white solid image displayed in tiling.
In FIG. 9, the first projection image IMG1 from the first projector PJ1 and the second projection image IMG2 from the second projector PJ2 are arranged in the horizontal direction adjacent to each other with an overlapping region. At this time, the luminance peak position of the first projection image IMG1 is C1, the luminance peak position of the second projection image IMG2 is C2, and the boundary positions of the overlapping regions are B1 and B2. Further, the luminance at the peak position C1 is Yc1, the luminance at the peak position C2 is Yc2, the luminance at the boundary position B1 is Yb1, and the luminance at the boundary position B2 is Yb2. Here, Yc1> Yb1 <Yb2 <Yc2 is set for the peak positions C1, C2 and the boundary positions B1, B2.

FIG. 10 shows an example of the color gamuts of the first projector PJ1 and the second projector PJ2 shown in FIG. FIG. 10 shows the white brightness by the second projector PJ2 as the reference white brightness in the uniform color space (specifically, L ^* u ^* v ^* ), and the color gamut of the first projector PJ1 is also the same reference white brightness. Is based on.
In FIG. 10, for the first projector PJ1, the peak color gamut CP1 at the peak position C1 and the boundary color gamut CB1 at the boundary position (including the boundary position B1) of the overlapping region are shown. In FIG. 10, for the second projector PJ2, the peak color gamut CP2 at the peak position C2 and the boundary color gamut CB2 at the boundary position (including the boundary position B2) of the overlapping region are shown. In FIG. 10, the lightness at the peak position C1 is L ^* c1, the lightness at the peak position C2 is L ^* c2, the lightness at the boundary position B1 is L ^* b1, and the lightness at the boundary position B2 is L ^* b2.

  Here, assuming that Yc1> Yb1 <Yb2 <Yc2 with respect to the peak positions C1, C2 and the boundary positions B1, B2, this magnitude relationship is maintained even after performing the conventional edge blending process. Therefore, a valley of brightness is recognized between the boundary positions B1 and B2 in FIG. 9, and even when the conventional color unevenness correction is performed, the color unevenness is basically corrected while inheriting the luminance distribution in the screen. In other words, even if the color unevenness is removed, the brightness unevenness remains. In such a valley of brightness, the visual unevenness may be severe.

  Therefore, in the first embodiment, by obtaining the unevenness correction target value as follows, there is little discomfort in the brightness and color difference of the tiling image after unevenness correction processing, and the image quality is improved.

FIG. 11 shows a first explanatory diagram related to the unevenness correction processing in the first embodiment. FIG. 11 illustrates an example of a change in luminance in the horizontal direction in the first projection image IMG1 and the second projection image IMG2 that are tiling-displayed. In FIG. 11, the same parts as those in FIG. In FIG. 11, the luminance after the unevenness correction processing at the boundary position B1 is represented as Yb1 ′.
First, in the unevenness correction processing according to the first embodiment, the luminance Yb1 at the boundary position B1 (first pixel position) and the luminance Yb2 at the boundary position B2 (second pixel position) are reduced to the lower luminance. The corresponding projector is the target of unevenness correction processing. In the case illustrated in FIG. 11, since Yb1 <Yb2, in the first embodiment, the first projector PJ1 corresponding to the luminance Yb1 is the target of unevenness correction processing. Thus, by increasing the luminance at the boundary position B1 of the first projector PJ1, it is possible to make the valley of brightness at the boundary positions B1 and B2 inconspicuous.

  Second, in the unevenness correction processing in the first embodiment, a pixel position equal to the luminance at the boundary position of the projection image by the non-correction target projector is detected in the projection image by the correction target projector. In the case shown in FIG. 11, in the first projection image IMG1 by the first projector PJ1, a pixel position A1 (third pixel position) having a luminance equal to the luminance Yb2 at the boundary position B2 is detected. Thereafter, in the first projection image IMG1, unevenness correction processing is performed from the pixel position A1 to the boundary end (first projection image end). That is, in the first embodiment, unevenness correction processing is performed based on the luminance Yb2 at the boundary position B2 in the non-overlapping area and the overlapping area of the first projection image IMG1. At this time, the unevenness correction target value is not limited to the gray axis from the pixel position A1 to the boundary edge, and the unevenness target value is calculated so that the change in brightness becomes small.

Third, in the unevenness correction process in the first embodiment, the unevenness correction process is performed from the pixel position A1 to the boundary edge so that the color difference ΔE from the pixel position A1 is minimized.
FIG. 12 shows a second explanatory diagram relating to the unevenness correction processing in the first embodiment. FIG. 12 shows an enlarged view around the gray axis in FIG. In FIG. 12, the lightness at the pixel position A1 is represented as L ^* a1, and the lightness after the unevenness correction processing at the boundary position B1 is represented as L ^* b1 ′.

That is, in the unevenness correction processing in the first embodiment, the lightness L ^* at the boundary position B1 so that the distance between the lightness at the pixel position A1 on the gray axis and the boundary color gamut CB1 of the first projector PJ1 is minimized ^. b1 'is determined. In the conventional method, the luminance decreases from the luminance Ya1 (= Yb2) to Yb1 at the pixel position A1, and a change of ΔE = ΔL ^* occurs in terms of the color difference. When the target gray axis matches the point where the angle of the color gamut outline is steep, the color difference change becomes larger. In the first embodiment, in such a case, the gray axis is changed in a direction (Yb1 ′, L ^* b1 ′) in which the color difference is smaller even if the chromaticity changes to some extent, thereby reducing brightness and color. Balance changes so that human visual changes are favorable. Even if ΔE is not a minimum condition, a limit may be provided for ΔEu ^* v ^* , which is a color difference component excluding lightness, and ΔE may be as small as possible within the limit.

  Fourth, in the unevenness correction processing in the first embodiment, the value is set to 0 over the other boundary so that the overlapped region is smoothly blended according to the unevenness correction target value of the non-overlapped region determined as described above. An uneven correction target value that converges is obtained (see FIG. 11).

That is, the luminance at the boundary position B1 of the overlapping region located at the boundary between the non-overlapping region and the overlapping region of the first projection image IMG1 is at the boundary between the non-overlapping region and the overlapping region of the second projection image IMG2. It is assumed that the luminance is lower than the luminance at the boundary position B2 of the superimposed region. At this time, in the first embodiment, the first unevenness correction processing unit 162 corrects unevenness based on the luminance Yb2 of the boundary position B2 in the non-overlapping region and the overlapping region of the first projection image IMG1.
Specifically, the first unevenness correction processing unit 162 has a pixel position A1 having a luminance corresponding to the luminance of the boundary position B2 in the first projection image IMG1 (the first in the non-overlapping region in the first projection image IMG1). 3) to the edge of the first projection image in the overlap region, the unevenness is corrected. It is desirable that the first unevenness correction processing unit 162 corrects unevenness so that the color difference with the pixel position A1 as a reference is minimized.

In the above description, the boundary positions B1 and B2 are assumed to be the boundary positions of the overlapping area. However, in the first embodiment, the boundary positions B1 and B2 are not limited to the boundary positions of the overlapping area. .
FIG. 13 is an explanatory diagram of the boundary position of the overlapping region in the first embodiment. FIG. 13 schematically shows a state in which the first projection image IMG1 and the second projection image IMG2 are arranged side by side on the screen SCR with a superimposed region.
The boundary position B1 described above may be a pixel position in the boundary portion AR1 between the non-overlapping area and the overlapping area of the first projection image IMG1. The boundary part AR1 is a region including the boundary between the non-overlapping region and the overlapping region of the first projection image IMG1 and the vicinity region thereof.
Similarly, the above-described boundary position B2 may be a pixel position in the boundary portion AR2 between the non-overlapping area and the overlapping area of the second projection image IMG2. The boundary part AR2 is a region including the boundary between the non-overlapping region and the overlapping region of the second projection image IMG2 and the vicinity thereof.

  When the white target value is obtained as described above, the unevenness correction target value calculation unit 130 determines the target gray axis in consideration of the difference in the color gamut other than white. As the white point moves toward black, the degree of freedom in setting the gray axis increases, so that the above-described ΔE is gradually decreased so that the color difference in the superimposed region is not noticeable.

FIG. 14 shows a third explanatory diagram relating to the unevenness correction processing in the first embodiment. FIG. 14 shows an enlarged view around the gray axis in FIG. In FIG. 14, the same parts as those in FIG. In FIG. 14, halftone grays at the peak position C1, the boundary position B1, and the pixel position A1 are represented as C1g, B2g, and A1g, respectively.
The unevenness correction target value calculation unit 130 connects, for example, the white lightness L ^* b1 ′ after unevenness correction processing at the boundary position B1 and the original black lightness L ^* bb at the boundary position B1 with a straight line or a curve. For example, the halftone target value is determined by equally dividing the two points.

  When the unevenness correction target value of the first projector PJ1 is determined as described above, the unevenness correction LUT can be generated by a known method. When the unevenness correction target value calculation unit 130 determines that the difference in brightness between the first projector PJ1 and the second projector PJ2 is large, the notification processing unit 150 changes the display condition of the tiling image. Performs processing to display a prompt screen. For example, the unevenness correction target value calculation unit 130 can determine that the difference in brightness between the two projectors is large when ΔE cannot be made smaller than a predetermined threshold. At this time, the unevenness correction target value calculation unit 130 compares the brightness Yb1 ′ at the boundary position B1 after unevenness correction processing with the brightness Yc1 at the peak position C1, for example, to determine the magnitude of the brightness difference between the two projectors. To do. By doing this, if the effect of unevenness correction cannot be obtained even when the brightness difference between the two projectors is large, the effect of unevenness correction can be sufficiently increased by increasing the size of the overlapping area. It will be obtained.

  As described above, in the first embodiment, the tiling image is displayed by the first projection image IMG1 and the second projection image IMG2. At this time, unevenness correction processing is performed based on the luminance Yb2 at the boundary position B2 in the non-overlapping area and the overlapping area of the first projection image IMG1 having low luminance at the boundary position B1. By doing so, it is possible to perform correction so as to reduce the change in the superimposition region in accordance with the display characteristics of each projector, and to improve the image quality of the tiling displayed image.

[Second Embodiment]
In the first embodiment, when the tiling image is displayed by the first projection image IMG1 and the second projection image IMG2, the first projector PJ1 that projects the first projection image IMG1 performs unevenness correction processing. Explained as a thing. However, the embodiment according to the present invention is not limited to this. In the second embodiment according to the present invention, both the first projector PJ1 and the second projector PJ2 perform unevenness correction processing.

FIG. 15 is a block diagram showing a configuration example of a multi-projection system according to the second embodiment of the present invention. In FIG. 15, the image processing apparatus is connected to the first projector and the second projector. In FIG. 15, the same parts as those in FIG.
The multi-projection system 10a includes a first projector PJ1a, a second projector PJ2, an image signal supply device 20, an unevenness measuring device 30, an image processing device 100a, and an operation unit 300a. The first projector PJ1a includes the image forming unit 200 shown in FIG. The image processing apparatus 100a has the same function as the image processing unit 100 in FIG. The operation unit 300a has the same function as the operation unit 300 in FIG. In the second embodiment, the first projection image IMG1 from the first projector PJ1a and the second projection image IMG2 from the second projector PJ2 are displayed side by side on the screen SCR with an overlapping region.

  FIG. 16 is a block diagram showing a configuration example of the image processing apparatus 100a shown in FIG. In FIG. 16, for convenience of explanation, the image signal supply device 20, the unevenness measurement device 30, the operation unit 300a, the first projector PJ1a, and the second projector PJ2 of FIG. 15 are also illustrated. In FIG. 16, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The image processing apparatus 100a includes an image division processing unit 110, an unevenness correction LUT selection unit 120a, an unevenness correction target value calculation unit 130a, an unevenness correction LUT generation unit 140a, and a notification processing unit 150. The image processing apparatus 100a includes a first unevenness correction LUT storage unit 160 and a first unevenness correction processing unit 162 corresponding to the first projector PJ1a. Furthermore, the image processing apparatus 100a includes a second unevenness correction LUT storage unit (second unevenness correction value storage unit) 170 and a second unevenness correction processing unit 172 corresponding to the second projector PJ2.

Image signals corresponding to the images divided by the image division processing unit 110 are output to the first projector PJ1a and the second projector PJ2.
The unevenness correction LUT selection unit 120a selects one of the unevenness correction LUTs stored in the first unevenness correction LUT storage unit 160 according to the type of the image signal from the image signal supply device 20 and the arrangement of the projector. Further, the unevenness correction LUT selection unit 120a selects one of the unevenness correction LUTs stored in the second unevenness correction LUT storage unit 170 in accordance with the type of the image signal from the image signal supply device 20 and the arrangement of the projector. .

  The unevenness correction target value calculation unit 130 a calculates a target value for unevenness correction of the image signal for each projector based on the unevenness measurement value of the projection image of each projector measured by the unevenness measuring device 30. At this time, the unevenness correction target value calculation unit 130a calculates the unevenness correction target value in at least a part of the overlapping region and the non-overlapping region of the first projection image IMG1 according to the setting content of the overlapping region. Further, the nonuniformity correction target value calculation unit 130a calculates the nonuniformity correction target value in at least a part of the superimposition area and the non-superimposition area of the second projection image IMG2 according to the setting content of the superposition area.

The unevenness correction LUT generation unit 140a generates an unevenness correction LUT in which unevenness correction values for performing unevenness correction processing in the first projector PJ1a are tabulated based on the unevenness correction target value calculated by the unevenness correction target value calculation unit 130a. . Further, the unevenness correction LUT generation unit 140a generates an unevenness correction LUT in which unevenness correction values for performing unevenness correction processing in the second projector PJ2 are tabulated based on the unevenness correction target value calculated by the unevenness correction target value calculation unit 130a. Generate.
The second unevenness correction LUT storage unit 170 stores the unevenness correction LUT generated by the unevenness correction LUT generation unit 140a. Similar to the first unevenness correction LUT storage unit 160, the second unevenness correction LUT storage unit 170 includes a memory such as an SRAM and a control unit that performs write control and read control on the memory.

  The second unevenness correction processing unit 172 performs unevenness correction processing using the unevenness correction LUT stored in the second unevenness correction LUT storage unit 170. In order to reduce the storage capacity, the second unevenness correction LUT storage unit 170 has corresponding unevenness correction values at a given number of lattice points in the three axes of the vertical direction of the screen × the horizontal direction of the screen × the gradation direction. Stored as LUT. For this reason, the second unevenness correction processing unit 172 obtains an unevenness correction value between lattice points from the unevenness correction value at the lattice point by a known interpolation operation such as linear interpolation or curve interpolation, and uses the unevenness correction value to perform unevenness correction processing. The image signal is obtained.

  In the unevenness correction processing by the image processing apparatus 100a as described above, the same processing as the unevenness correction processing by the image processing unit 100 in the first embodiment is performed on the image signal for each projector. Therefore, illustration and description of the processing contents of the image processing apparatus 100a in the second embodiment are omitted.

  Here, in the case of a projector having a large peripheral light reduction, in the first embodiment, there may be a case where brightness unevenness is a concern. In this case, according to the second embodiment, the target value of the boundary between both projectors is changed so that the projector peak is not noticeable, so that the luminance change in the tiling state becomes smoother. Can do.

FIG. 17 shows a first explanatory diagram related to the unevenness correction processing in the second embodiment. FIG. 17 shows an example of a change in luminance in the horizontal direction in the first projection image IMG1 and the second projection image IMG2 displayed in tiling. In FIG. 17, the same parts as those in FIG.
In the unevenness correction processing according to the second embodiment, the luminance at the boundary positions B1 and B2 of the overlapping region is increased so that ΔE that is the color difference from the peak positions C1 and C2 is as small as possible. As a result, in FIG. 17, the luminance at the boundary position B1 is Yb1 ″ and the luminance at the boundary position B2 is Yb2 ′. In this way, by performing the unevenness correction process also on at least a part of the non-overlapping area of the first projection image IMG1 and the second projection image IMG2, it is possible to further smooth the luminance change in the overlapping area. It becomes like this.

FIG. 18 shows a second explanatory diagram regarding the unevenness correction processing in the second embodiment. FIG. 18 shows an enlarged view around the gray axis in FIG. In FIG. 18, the same parts as those in FIG.
In the unevenness correction processing in the second embodiment, the lightness L ^* b1 ″ at the boundary position B1 is determined so that the color difference from the peak position C1 to the boundary position B1 is minimized. Then, a straight line is formed so that the color difference from the peak position C2 to the boundary position B1 is minimized, and the position where the straight line intersects the boundary color gamut CB2 is defined as the lightness L ^* b2 ′ at the boundary position B2. That is, the second unevenness correction processing unit 172 performs the superimposition so that the color difference between the boundary position B1 corrected by the first unevenness correction processing unit 162 and the luminance peak position C2 in the second projection image IMG2 is minimized. The unevenness is corrected for the non-overlapping region between the region and the second projection image IMG2.

Also in the unevenness correction process in the second embodiment, the unevenness correction target value is obtained so that the overlapping region is smoothly blended as in the first embodiment. Then, the unevenness correction target value calculation unit 130a determines a halftone target value, as in the first embodiment.
Thus, when the unevenness correction target value is determined for each projector, the unevenness correction LUT generation unit 140a generates an unevenness correction LUT by a known method. When the unevenness correction target value calculation unit 130a determines that the brightness difference between the first projector PJ1 and the second projector PJ2 is large, the notification processing unit 150 changes the tiling image display condition. A process for displaying a prompting screen may be performed.

  As described above, according to the second embodiment, the unevenness correction process is performed on the first projection image IMG1 and the second projection image IMG2, so that it is much more than that of the first embodiment. Thus, the luminance change in the superposed region can be smoothed.

[First Modification of Second Embodiment]
In the second embodiment, the unevenness correction process is performed by increasing the luminance at the boundary positions B1 and B2 in the overlapping region. However, the brightness valley may not be eliminated in the overlapping region. Therefore, in the first modification of the second embodiment, the luminance (brightness) at the boundary positions B1 and B2 in the overlapping region is set so that the change in lightness in the overlapping region becomes a monotone change (monotonically increasing or decreasing). Determine.

FIG. 19 is an explanatory diagram related to unevenness correction processing in the first modification of the second embodiment. FIG. 19 shows an enlarged view around the gray axis in FIG. In FIG. 19, the same parts as those in FIG.
In the first modification, the lightness L ^* b1 ″ at the boundary position B1 is determined so as to have the same lightness as the peak position C1. Then, a straight line is formed so that the color difference from the peak position C2 to the boundary position B1 is minimized, and the position where the straight line intersects the boundary color gamut CB2 is defined as the lightness L ^* b2 ′ at the boundary position B2. That is, the first unevenness correction processing unit 162 and the second unevenness correction processing unit 172 are configured so that the change in brightness between the luminance peak position C1 and the luminance peak position C2 is monotonously changed. Unevenness is corrected for the non-superimposed region of the image.

  Also in the first modification of the second embodiment, as in the second embodiment, the unevenness correction target value is obtained so that the overlapping region is blended smoothly. Then, the unevenness correction target value calculation unit 130a determines a halftone target value, as in the second embodiment. Thus, when the unevenness correction target value is determined for each projector, the unevenness correction LUT generation unit 140a generates an unevenness correction LUT by a known method.

[Second Modification of Second Embodiment]
In the first modification of the second embodiment, the lightness at the boundary position B1 is determined so as to have the same lightness as the peak position C1, but the present invention is not limited to this. In the second modification, the lightness L ^* b1 ″ at the boundary position B1 is determined so that the sum of the color differences from the peak positions C1 and C2 is minimized.

FIG. 20 is an explanatory diagram related to unevenness correction processing in the second modification of the second embodiment. FIG. 20 shows an enlarged view around the gray axis in FIG. 20, parts that are the same as those in FIG. 18 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.
In the second modification, the lightness L ^* b1 ″ at the boundary position B1 is determined so that the color difference from the peak positions C1 and C2 is minimized. That is, the lightness L ^* b1 ″ at the boundary position B1 is determined so that the sum of the color difference between the peak position C1 and the boundary position B1 and the color difference between the peak position C2 and the boundary position B1 is minimized. Then, a straight line is formed so that the color difference from the peak position C2 to the boundary position B1 is minimized, and the position where the straight line intersects the boundary color gamut CB2 is defined as the lightness L ^* b2 ′ at the boundary position B2. That is, the first unevenness correction processing unit 162 and the second unevenness correction processing unit 172 include the first color difference between the luminance peak position C1 and the boundary position B1 corrected by the first unevenness correction processing unit 162, and the first unevenness. Unevenness is corrected for the superimposition region and the non-superimposition region of each projection image so that the sum of the second color difference between the boundary position B1 and the peak position C2 after correction by the correction processing unit 162 is minimized.

  Also in the second modification of the second embodiment, as in the second embodiment, the unevenness correction target value is obtained so that the overlapping region is blended smoothly. Then, the unevenness correction target value calculation unit 130a determines a halftone target value, as in the second embodiment. Thus, when the unevenness correction target value is determined for each projector, the unevenness correction LUT generation unit 140a generates an unevenness correction LUT by a known method.

  As described above, in the second embodiment, since the degree of freedom in setting the unevenness correction target value is increased, various patterns as described above are conceivable. Further, in order to make the process of the overlapping area as conscious as possible by the user, the color difference between the boundary position B1 and the boundary position B2 may be made as small as possible. Further, the user may be able to select the unevenness correction process by selecting the selection unit.

  As described above, the image processing apparatus, the image display apparatus, the image processing method, and the like according to the present invention have been described based on any one of the above-described embodiments or modifications thereof, but the present invention is any of the above-described embodiments or modifications thereof. It is not limited to examples. The present invention can be implemented in various modes without departing from the gist thereof, and for example, the following modifications are possible.

  (1) In the above-described embodiment or its modification, an example in which an image formed by two image forming units is tiled has been described. However, an image formed by three or more image forming units may be resistant to rinsing. It is the same.

(2) In the above embodiment or its modification, the example in which the image forming unit according to the present invention is configured by a light valve using a so-called three-plate transmission type liquid crystal panel has been described. A light valve using a panel or a transmissive liquid crystal panel of 2 plates or 4 plates or more can be employed. In addition, although it has been described that a light valve using a transmissive liquid crystal panel is used as the light modulation element, the present invention is not limited to this. As a light modulation element, for example, DLP (Digital Light Processing) (registered trademark), LCOS (Liquid
Crystal On Silicon) may be employed, or a configuration in which these are mixed may be employed.

  (3) In the above-described embodiment or its modification, the example in which the image display apparatus according to the present invention is a projector has been described, but the present invention is not limited to this.

(4) In the above embodiment or its modification, the L ^* u ^* v ^* space has been described as an example of the uniform color space, but the present invention is not limited to this. For example, the L ^* a ^* b ^* space may be used as the uniform color space.

  (5) Although the present invention has been described as an image processing apparatus, an image display apparatus, an image processing method, and the like in the above-described embodiment or its modification, the present invention is not limited to this. For example, a program that describes the processing procedure of the image processing method and the unevenness correction value generation method according to the present invention, and a program that describes the processing procedure of the processing method (image display method) of the image display device for realizing the present invention A recording medium on which any one of these programs is recorded may be used.

10, 10a ... multi-projection system (display system),
20 ... Image signal supply device, 30 ... Unevenness measurement device,
100: Image processing unit (image processing apparatus), 100a: Image processing apparatus,
110: Image division processing unit, 120, 120a: Unevenness correction LUT selection unit,
130, 130a ... unevenness correction target value calculation unit, 140, 140a ... unevenness correction LUT generation unit,
150 ... notification processing unit,
160... First unevenness correction LUT storage unit (first unevenness correction value storage unit),
162: First unevenness correction processing unit,
170 ... second unevenness correction LUT storage unit (second unevenness correction value storage unit),
172: Second unevenness correction processing unit 200: Image forming unit 300, 300a: Operation unit,
A1 ... Pixel position (third pixel position), AR1, AR2 ... Boundary part,
B1 ... boundary position (first pixel position), B2 ... boundary position (second pixel position),
C1, C2 ... peak position, CB1 ... boundary color gamut of the first projector,
CB2: boundary color gamut of the second projector,
CP1: Peak color gamut of the first projector,
CP2 ... peak color gamut of the second projector, IMG1 ... first projection image,
IMG2 ... second projection image,
L ^* a1, L ^* b1, L ^* b1′L ^* b1 ″, L ^* b2, L ^* c1, L ^* c2… lightness,
PJ1, PJ1a ... first projector (first image display device),
PJ2 ... second projector (second image display device) SCR ... screen,
Yb1, Yb1 ′, Yb1 ″, Yb2, Yb2 ′, Yc1, Yc2... Luminance

Claims (8)

An image processing apparatus that corrects unevenness of a tiling image in which a first projection image and a second projection image are arranged with an overlapping region,
A first unevenness correction value storage unit that stores a correction value for correcting unevenness of the first projection image;
A first unevenness correction processing unit that corrects unevenness of the first projected image using a correction value stored in the first unevenness correction storage unit,
The luminance of the first pixel position at the boundary between the non-overlapping area of the first projection image and the overlapping area is the second luminance at the boundary between the non-overlapping area of the second projection image and the overlapping area. Lower than the brightness of the pixel position,
The first unevenness correction processing unit corrects unevenness based on the luminance of the second pixel position in a non-overlapping area and the overlapping area of the first projection image. In claim 1,
The first unevenness correction processing unit includes:
In the first projection image, the first projection in the superimposition region from the third pixel position in the non-superimposition region in the first projection image having a luminance corresponding to the luminance of the second pixel position. An image processing apparatus that corrects unevenness over an image edge. In claim 2,
The first unevenness correction processing unit includes:
An image processing apparatus that corrects unevenness so that a color difference based on the third pixel position is minimized. In any one of Claims 1 thru | or 3,
A second unevenness correction value storage unit for storing a correction value for correcting unevenness of the second projection image;
A second unevenness correction processing unit that corrects unevenness of the second projected image using the correction value stored in the second unevenness correction storage unit,
The second unevenness correction processing unit includes:
An image in which unevenness is corrected so that a color difference between the first pixel position corrected by the first unevenness correction processing unit and a luminance peak position in the second projection image is minimized. Processing equipment. In claim 1 or 2,
A second unevenness correction value storage unit for storing a correction value for correcting unevenness of the second projection image;
A second unevenness correction processing unit that corrects unevenness of the second projected image using the correction value stored in the second unevenness correction storage unit,
The first unevenness correction processing unit and the second unevenness correction processing unit are:
The first color difference between the luminance peak position in the first projection image and the first pixel position after the correction by the first unevenness correction processing unit, and the correction after the correction by the first unevenness correction processing unit An unevenness is corrected so that the sum of the 1st pixel position and the 2nd color difference of the peak position of the brightness in the 2nd projection picture may become the minimum. In claim 1 or 2,
A second unevenness correction value storage unit for storing a correction value for correcting unevenness of the second projection image;
A second unevenness correction processing unit that corrects unevenness of the second projected image using the correction value stored in the second unevenness correction storage unit,
The first unevenness correction processing unit and the second unevenness correction processing unit are:
An image in which unevenness is corrected so that a change in brightness becomes a monotonous change between a luminance peak position in the first projection image and a luminance peak position in the second projection image. Processing equipment.   An image display apparatus comprising the image processing apparatus according to claim 1. An image processing method for correcting unevenness of a tiling image in which a first projection image and a second projection image are arranged with a superimposed region,
The luminance of the first pixel position at the boundary between the non-overlapping area and the overlapping area in the first projection image is the luminance at the boundary between the non-overlapping area and the overlapping area in the second projection image. Lower than the brightness of the pixel position of 2,
An image processing method, comprising: correcting unevenness in a non-overlapping area and the overlapping area of the first projection image based on a luminance of the second pixel position.

Images