JP5369392B2 - Multi-projection system - Google Patents

Description

  The present invention relates to a light amount adjustment device for a superimposing region in a multi-projection system that displays a large screen image by projecting projection images from adjacent projectors so as to have a superimposing region on the screen. The present invention relates to a light amount adjustment method for a superimposition region, a multi-projection system, and a light amount adjustment control device.

  A multi-projection system that displays a large screen image by projecting a projection image from an adjacent projector among projection images projected from a plurality of projectors so as to have a superimposed region on a screen is known.

  In such a multi-projection system, there is a problem that the overlapping area becomes conspicuous because the overlapping area becomes brighter than other areas. Various methods for solving this have been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

The technique disclosed in Patent Document 1 adjusts the brightness of a superimposed region by performing light amount adjustment by software through image processing.
The technique disclosed in Patent Document 2 adjusts the brightness of the overlapping region by optically adjusting the amount of light with a light shielding plate installed between the projection optical system of each projector and the screen. .
The technique disclosed in Patent Document 3 is a combination of a method for performing light amount adjustment by software by image processing and a method for performing light amount adjustment optically using a light shielding plate.

JP 2002-116500 A Japanese Patent Laid-Open No. 5-103286 JP 2001-343704 A

  As in the technique disclosed in Patent Document 1 described above, according to the method of adjusting the amount of light by software by image processing, an image having a high pixel value and a low spatial frequency (such as a sky or a snowy field spreading all over). In a bright image with little color change, the difference in brightness between the superimposed region and other regions can be reduced to an inconspicuous level.

  However, in the method of adjusting the amount of light by software by image processing, when a black image is displayed by each adjacent projector, since a certain amount of light is projected, a phenomenon called black floating occurs, There is a problem that in the overlap region, it is amplified and becomes brighter than other regions. For this reason, in the case of projecting a dark image (an image such as a night view) with a low pixel value, there is a problem that the difference in brightness between the superimposed region and other regions becomes conspicuous.

  In addition, according to the method of optically adjusting the amount of light using a light shielding plate as in the technique disclosed in Patent Document 2, in a dark image or an image with a high spatial frequency as described above, It is possible to reduce the difference in brightness from other regions until it is hardly noticeable.

  However, in the method of optically adjusting the brightness of the superimposed region using a light shielding plate, a difference in brightness between the superimposed region and other regions becomes conspicuous in an image having a high pixel value and a low spatial frequency. There is. Further, when the light amount adjustment of the overlapping area is performed only by the light shielding plate, there is a problem that the adjustment of the position and the shape of the light shielding plate installed corresponding to each projector is complicated.

  Further, as in the technique disclosed in Patent Document 3, the light amount adjustment is performed by combining the method of adjusting the light amount by software by image processing and the method of optically adjusting the light amount using a light shielding plate. The problem described above is considered to be solved.

  However, by simply combining the method of adjusting the amount of light by software using image processing and the method of adjusting the amount of light optically using a light-shielding plate, a large number of projectors are arranged in the vertical and horizontal directions, respectively. When a multi-projection system that allows display on a large screen such as the above screen is configured, depending on the characteristics of the projected image, such as a dark image with a low pixel value or an image with a high pixel value and a low spatial frequency, It was found that the problem that the difference in brightness from other areas was conspicuous could not be solved.

  Therefore, the present invention relates to the characteristics of a projected image when displaying a large screen by projecting a projected image from an adjacent projector among projected images from a plurality of projectors so as to have a superimposed region on the screen. It is an object of the present invention to provide a light amount adjustment device for a superposition region, a light amount adjustment method for a superposition region, a multi-projection system, and a light amount adjustment control device capable of minimizing the difference in brightness between the superposition region and another region. And

  (1) The superimposing area light amount adjusting apparatus according to the present invention displays a projected image from a plurality of projectors on a screen so that a superimposed area is formed between projected images projected from adjacent projectors among the plurality of projectors. A superimposing area light amount adjusting device used in a multi-projection system for projecting to a light-shielding device that optically adjusts the superimposing area light amount, an image processing unit that adjusts the superimposing area light amount by image processing, and And a light amount adjustment control device having a light amount adjustment degree setting unit that sets a degree of light amount adjustment by a light shielding device and a degree of light amount adjustment by the image processing unit according to characteristics of the projection image.

As described above, the light amount adjustment device for the overlapping region according to the present invention sets the light amount adjustment degree (adjustment amount) by the light shielding device and the light amount adjustment degree (adjustment amount) by the image processing unit according to the characteristics of the projection image. Like to do. This makes it possible to project dark images with low pixel values, images with high pixel values and low spatial frequency (bright images with little color change), images with high pixel values and high spatial frequency (bright images with many color changes), etc. Regardless of the characteristics of the image, the difference in brightness between the superimposed region and other regions can be minimized, and a good image can be obtained in which the superimposed region is not conspicuous. Depending on the content of the projected image, etc., for example, by setting either one of the degree of light amount adjustment by the image processing unit and the light shielding device to 0, light amount adjustment using either the light shielding device or the image processing selectively may be performed. Is possible.
Note that “optically adjusting the amount of light in the overlapping region” means adjusting the amount of light in the overlapping region using hardware such as a light shielding plate.
Further, “adjusting the light amount of the superimposition region by image processing” means performing light amount adjustment of the superimposition region by adjusting the pixel value of the image data corresponding to the projection image projected on the superimposition region.

  (2) In the light amount adjustment device for the overlapping region described in (1), the light amount adjustment control device analyzes image data corresponding to the projection image and determines characteristics of the projection image. It is preferable to have.

  As described above, the light amount adjustment control apparatus includes the image data analysis unit that analyzes the image data corresponding to the projection image and determines the characteristic of the projection image, thereby appropriately determining the characteristic of the projection image. . Thereby, the light quantity adjustment degree setting unit can appropriately set the degree of light quantity adjustment by the light shielding device and the degree of light quantity adjustment by the image processing unit according to the characteristics of the projection image.

  (3) In the light amount adjustment device for the overlapping region described in (2), the image data analysis unit weights image data corresponding to the overlapping region and a projection image around the overlapping region, and the weighting is performed. It is also possible to analyze the image data subjected to the above.

  In this way, the image data corresponding to the superimposed region and the projection image around the superimposed region is weighted, and the weighted image data is analyzed, thereby corresponding to the superimposed region and the surrounding projected image. The image data focused on the image data to be analyzed can be analyzed, and the characteristics of the projection image determined by this analysis appropriately represent the characteristics of the projection image in the superimposed region.

(4) In the light amount adjustment device for the overlap area described in (2) or (3), the image data analysis unit determines the characteristics of the projection image for each frame when the projection image is a moving image. It is preferable to do.
In this way, when the projection image is a moving image, it is possible to acquire the characteristics of the projection image according to changes in the scene by determining the characteristics of the projection image for each frame, and thereby the superimposition region The amount of light can be adjusted following the changes in the scene.

(5) In the superimposing region light amount adjustment device according to any one of (1) to (4), the characteristics of the projection image depend on the pixel value and the spatial frequency of the image data corresponding to the projection image. It is preferable to represent.
As described above, the characteristics of the projection image are expressed by the pixel value of the projection image and the level of the spatial frequency, so that it is possible to appropriately determine the characteristics of the projection image necessary for adjusting the light amount of the overlapping region. .

  (6) In the light amount adjustment device for a superimposition region described in (5), the light amount adjustment degree setting unit is a space in which a projection image with a pixel value equal to or less than a first predetermined value or a pixel value is higher than the first predetermined value. For a projected image having a frequency higher than the second predetermined value, the degree of light amount adjustment by the light shielding device is made higher than that of a projected image having a pixel value higher than the first predetermined value and a spatial frequency equal to or lower than the second predetermined value. For a projected image having a pixel value higher than the first predetermined value and a spatial frequency equal to or lower than the second predetermined value, a projected image or pixel value having a pixel value equal to or lower than the first predetermined value is higher than the first predetermined value. It is preferable that the degree of light amount adjustment by the image processing unit is higher than that of a projection image having a high spatial frequency higher than the second predetermined value.

For an image with a low pixel value (a dark image such as a night scene) or an image with a high pixel value and a high spatial frequency (a bright image with many color changes), the degree of light amount adjustment by the shading device is increased. For an image having a high value and a low spatial frequency (bright image with little color change), the degree of light amount adjustment by the image processing unit is increased.
Note that the determination of the pixel value and the spatial frequency is, for example, a value set to enable appropriate determination of the pixel value and the spatial frequency (the first predetermined value, the spatial frequency for the pixel value). For the second predetermined value). The first predetermined value and the second predetermined value will be described later.

  Thus, by setting the degree of optical light amount adjustment by the light-shielding device and the degree of software light amount adjustment by the image processing unit according to the characteristics of the projected image, the light amount adjustment of the superimposed region can be adjusted. It can be performed appropriately according to the characteristics. Thereby, the brightness of the superimposed region and other regions can be made inconspicuous regardless of the characteristics of the projected image. In particular, a remarkable effect can be obtained in a multi-projection system or the like in which a large number of projectors are arranged in the vertical direction and the horizontal direction to enable display on a large screen such as a movie theater screen.

  (7) In the light amount adjustment device for the overlapping region according to any one of (1) to (6), the light shielding device is provided for each projector, and a part of the projection light from the corresponding projector is predetermined. It is preferable to have a movable light-shielding plate that can block light with a light transmittance, and to adjust the light amount of the overlapping region by changing the position of the movable light-shielding plate.

  In this configuration, for example, a light shielding plate having a shape corresponding to a superimposed region formed between projection images projected from adjacent projectors can be changed in position from side to side and up and down. When the light shielding device has such a movable light shielding plate, the light shielding device can change the position of the light shielding plate within a predetermined range based on a control signal from the light amount adjustment degree setting unit. Thereby, the light quantity of a superimposition area | region can be adjusted within a predetermined range.

  (8) In the light amount adjustment device for the overlapping region according to any one of (1) to (6), the light shielding device is provided for each projector, and a part of the projection light from the corresponding projector It is also preferable to have a light shielding plate that can change the light transmittance within a predetermined range, and to adjust the light amount of the overlapping region by changing the light transmittance of the light shielding plate.

  This makes it possible to use electrochromic glass or the like whose light transmittance can be changed as a light shielding plate. In this way, by using electrochromic glass or the like as the light shielding plate, the light amount of the overlapping region can be adjusted within a predetermined range without changing the position of the light shielding plate.

  (9) The method for adjusting the amount of light in the superimposed area according to the present invention is configured to display the projected images from the plurality of projectors on a screen so that a superimposed area is formed between the projected images projected from adjacent projectors among the plurality of projectors. A method for adjusting the amount of light in a superimposition area used in a multi-projection system for projecting to a light source, comprising: a light shielding device that optically adjusts the light amount in the superposition area; and an image processing unit that performs light amount adjustment in the superposition area by image processing. The degree of light amount adjustment by the light shielding device and the degree of light amount adjustment by the image processing unit are set according to the characteristics of the projection image.

  As described above, the method for adjusting the amount of light in the overlapping region of the present invention can obtain the same effect as the light amount adjusting device for the overlapping region described in (1). The superimposing region light amount adjusting method of the present invention described in (9) preferably has the same characteristics as the superimposing region light amount adjusting device described in (2) to (8).

  (10) The multi-projection system of the present invention includes a plurality of projectors arranged so that a superimposed region is formed between projection images projected from adjacent projectors, and a light amount of a superimposed region that performs light amount adjustment of the superimposed region. The superimposing area light amount adjusting device includes a light shielding device that optically adjusts the light amount of the overlapping area, and an image processing unit that performs light amount adjustment of the overlapping area by image processing. And a light amount adjustment control device having a light amount adjustment degree setting unit that sets a degree of light amount adjustment by the light shielding device and a degree of light amount adjustment by the image processing unit in accordance with characteristics of the projection image. .

  As described above, also in the multi-projection system of the present invention, it is possible to obtain the same effect as that of the light amount adjusting device for the overlapping region described in (1). Note that the multi-projection system described in (10) preferably has the same characteristics as the light amount adjustment device for the overlapping region described in (2) to (8).

  (11) The light amount adjustment control device of the present invention optically adjusts the light amount of a plurality of projectors arranged so that a superimposed region is formed between projection images projected from adjacent projectors. A light amount adjustment control device used in a multi-projection system having a light shielding device, wherein the image processing unit performs light amount adjustment of the overlapping region by image processing, a degree of light amount adjustment by the light shielding device, and a light amount by the image processing unit And a light amount adjustment degree setting unit for setting the degree of adjustment according to the characteristics of the projection image.

By providing such a light quantity adjustment control device in the multi-projection system, the degree of light quantity adjustment by the light shielding device and the degree of light quantity adjustment by the image processing unit can be set according to the characteristics of the projected image. This makes it possible to project dark images with low pixel values, images with high pixel values and low spatial frequency (bright images with little color change), images with high pixel values and high spatial frequency (bright images with many color changes), etc. Regardless of the characteristics of the image, the difference in brightness between the superimposed region and other regions can be minimized, and a good image can be obtained in which the superimposed region is not conspicuous. Depending on the content of the projected image, etc., it is possible to adjust the light amount by selectively using either the light shielding device or the image processing.
Note that the light amount adjustment control device described in (11) preferably has the same characteristics as the light amount adjustment device in the overlapping region described in (2) to (8).

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a diagram schematically showing the arrangement of projectors in a multi-projection system according to an embodiment of the present invention. In the multi-projection system according to the embodiment of the present invention, a large number of projectors are arranged in the horizontal direction and the vertical direction to enable display on a large screen such as a movie theater screen. In order to simplify the description, as shown in FIG. 1, an example using a total of four projectors PJ1 to PJ4, two in the horizontal direction and two in the vertical direction will be described.

The multi-projection system according to the embodiment of the present invention is a back-type multi-projection system that projects from the back surface of the screen SCR.
Although not shown in FIG. 1, each of the projectors PJ1 to PJ4 is provided with a light-shielding device that can optically adjust the amount of light in an overlapping area formed between projection images projected from adjacent projectors. It shall be.

  FIG. 2 is a diagram schematically illustrating an example of a light shielding device used in the multi-projection system according to the embodiment. As shown in FIG. 1, the multi-projection system according to the embodiment is arranged so that a superimposed region is formed between projection images from adjacent projectors. Therefore, the light shielding devices S1 to S4 for adjusting the light amounts of the respective overlapping regions are arranged as shown in FIG. 2 corresponding to the projectors PJ1 to PJ4.

  Each of the light shielding devices S1 to S4 shown in FIG. 2 has L-shaped light shielding parts 11, 21, 31, 41 shown in gray and light transmitting parts 12, 22, 32, 42 shown in white. ing. Further, the L-shaped light shielding portions 11, 21, 31, 41 of each of the light shielding devices S1 to S4 include the light shielding plates 11a, 21a, 31a, 41a in the vertical direction and the light shielding plates 11b, 21b, 31b, 41b in the horizontal direction. have. The vertical light shielding plates 11a, 21a, 31a and 41a and the horizontal light shielding plates 11b, 21b, 31b and 41b are movable, and the light shielding range of the projection light from the corresponding projector can be changed. It is like that.

  FIG. 3 is a diagram for explaining an example of the movement of the light shielding plates 11a and 11b of the light shielding device S1 among the light shielding devices S1 to S4 shown in FIG. As shown in FIG. 3, the light shielding plates 11a and 11b can slide within a predetermined range in the horizontal direction (arrow h-h 'direction) and the vertical direction (arrow v-v' direction), respectively. Further, it may be rotatable within a predetermined angle in the direction of arrow cc ′ or arrow dd ′, and can be slid within a predetermined range in an oblique direction (direction of arrow ee ′). It may be. Such a configuration is the same for each light shielding plate in the other light shielding devices S2 to S4.

  In addition, each light-shielding device S1-S4 shall be provided with the light-shielding plate drive mechanism (not shown) for moving the light-shielding plate which self has as shown in FIG. The light shielding plate driving mechanism drives each light shielding plate by a control signal from the light amount adjustment degree setting unit 103 (see FIG. 6).

FIG. 4 is a diagram showing an example in which the light shielding range of the overlapping region is changed by changing the position of the light shielding plate of each light shielding device provided corresponding to two adjacent projectors. FIG. 5 is a diagram showing a change in the light amount of the overlapping region by changing the position of the light shielding plate.
4 and 5, two projectors (projectors PJ1 and PJ2) adjacent in the horizontal direction in the multi-projection system shown in FIG. 1 will be described as an example.

  As shown in FIGS. 4A and 4B, the positions of the light shielding plates 11a and 21a in the vertical direction of the light shielding devices S1 and S2 respectively corresponding to the projectors PJ1 and PJ2 are moved in the horizontal direction (left and right direction in FIG. 4). By doing so, the light shielding range for the projection light of the projectors PJ1 and PJ2 can be changed.

  That is, in FIG. 4A, the light shielding plates 11a and 21a are positions that shield light from a range corresponding to the entire overlapping region A0. On the other hand, in FIG. 4B, the light shielding plate 11a is in a position for shielding the region A1 in the overlapping region A0, and the light shielding plate 21a is in a position for shielding the region A2 in the overlapping region A0. It has become.

  As described above, the positions of the light shielding plates 11a and 21a of the respective light shielding devices S1 and S2 provided corresponding to the projectors PJ1 and PJ2 are changed to overlap the projection images formed from the projectors PJ1 and PJ2. The light shielding range in the region can be changed.

  FIG. 5A is an example conceptually showing a change in light amount in the overlapping region when the light shielding plates 11a and 21a of the light shielding devices S1 and S2 are set to the positions shown in FIG. 4A. When the light shielding plates 11a and 21a of the light shielding devices S1 and S2 are positioned as shown in FIG. 4A, as shown in FIG. 5A, the light quantity in the overlapping region A0 by the light shielding plate 11a is indicated by C1. Thus, the amount of light from the light shielding plate 21a changes as indicated by C2.

  As described above, when the light shielding plates 11a and 21a are set to the positions shown in FIG. 4A, the light amount in the overlapping region A0 can be made substantially the same as the light amount in the other regions. Although the change in the light quantity is actually a curve, FIG. 5 is a straight line because it conceptually shows the change in the light quantity.

  FIG. 5B is an example conceptually showing a change in light amount in the overlapping region when the light shielding plates 11a and 21a of the light shielding devices S1 and S2 are set to the positions shown in FIG. 4B. As shown in FIG. 5B, when the light shielding plates 11a and 21a of the light shielding devices S1 and S2 provided corresponding to the projectors PJ1 and PJ2 are positioned as shown in FIG. 4B, the light shielding plate 11a. The amount of light in the overlap area A0 due to the change changes as indicated by C3, and the amount of light in the overlap area due to the light shielding plate 21a changes as indicated by C4.

  As described above, when the light shielding plates 11a and 21a are set to the positions shown in FIG. 4B, the light amount in the overlapping area A0 changes so as to gradually increase from both ends of the overlapping area A0 toward the center. .

  FIG. 5C shows a case where the light shielding plates 11a and 21a of the light shielding devices S1 and S2 are in positions where they do not block the projection light from the projectors PJ1 and PJ2. In this case, the amount of light in the overlapping area A0 is It will be in the state which increased in the whole superimposition area | region A0.

  As shown in FIGS. 4 and 5, the amount of light in the overlapping region on the screen SCR can be adjusted by changing the positions of the light shielding plates 11a and 21a of the light shielding devices S1 and S2.

  4 and 5, the adjacent projectors PJ1 and PJ2 of the four projectors constituting the multi-projection system have been described, but other adjacent projectors constituting the multi-projection system can be considered in the same manner.

  Although the above has described the case where the light amount adjustment of the overlapping region is optically performed by the light shielding devices S1 to S4, the light amount adjustment of the overlapping region can also be performed by software by image processing.

  In the multi-projection system according to the embodiment of the present invention, the degree of optical light amount adjustment by the light-shielding devices S1 to S4 and the degree of software light amount adjustment by the image processing unit 102 (see FIG. 6) are expressed as projection image characteristics. Accordingly, the amount of light in the overlapping area on the screen SCR is adjusted.

  FIG. 6 is a diagram for explaining functions of the multi-projection system according to the embodiment of the present invention. As shown in FIG. 6, the multi-projection system according to the embodiment of the present invention includes a plurality of projectors (in the embodiment, four projectors PJ1 to PJ4), and a superimposing region that enables light amount adjustment of the superimposing region. A light amount adjusting device 100, an image data input unit 110 for inputting image data corresponding to an image to be projected (referred to as a projected image) from a television (TV) antenna, a DVD player, a personal computer (PC), and the like; An adjustment image data storage unit 111 that stores image data, a correction parameter storage unit 112 that stores correction parameters, and an imaging device 113 that captures a projected image on a screen SCR (see FIG. 1).

  The light amount adjustment device 100 for the overlap region analyzes the image data corresponding to the projection image by the light shielding devices S1 to S4 (see FIGS. 2 and 3) that optically adjust the light amount of the overlap region, and the characteristics of the projection image The image data analysis unit 101 for determining the amount of light, the image processing unit 102 having a function of performing the light amount adjustment of the overlapping area in software, the degree of light amount adjustment by the light shielding devices S1 to S4, and the degree of light amount adjustment by the image processing unit 102 And a light amount adjustment degree setting unit 103 having a function of setting according to the characteristics of the projected image.

  The image data analysis unit 101, the image processing unit 102, the light amount adjustment degree setting unit 103, and the like are included in the light amount adjustment control device 200 of the multi-projection system. The light amount adjustment control device 200 is a personal computer (PC). ) And the like.

  In addition to the components shown in FIG. 6, for example, a unit for generating image data (unit image data) corresponding to an image (unit image) that each projector takes from image data input to the image data input unit 110. Although there are various components necessary for configuring the multi-projection system, such as an image data generation unit, they are not shown.

  In the correction parameter storage unit 112, data indicating the movement amount (movement amount according to the characteristics of the projected image) with respect to the light shielding plate (see FIGS. 2 and 3) included in each of the light shielding devices S1 to S4, and the image in the overlapping region. Data for correcting pixel values of data, data for correcting luminance differences and color unevenness of the entire projection image projected on the screen SCR, and the like are stored as correction parameters.

  The correction parameters stored in the correction parameter storage unit 112 are the projectors PJ1 to PJ4 projecting the adjustment image corresponding to the adjustment image data stored in the adjustment image data storage unit 111 on the screen SCR. The projected image for adjustment is picked up by the image pickup device 113 and determined based on the picked-up image data obtained thereby.

  In such a configuration, the light amount adjustment processing will be described. First, the image data analysis unit 101 performs image data analysis processing on the image data input to the image data input unit 110, and determines the characteristics of the projection image based on the image data analysis result.

The image data analysis processing by the image data analysis unit 101 is performed, for example, by checking the pixel value and the spatial frequency of the image data corresponding to the projection image for one screen, the brightness of the projection image, the smoothness of the projection image (the spatial frequency The degree of elevation).
The determination of the pixel value and the spatial frequency of the image data is a reference value for enabling appropriate determination of the pixel value and the spatial frequency. For the pixel value, the first predetermined value and the spatial frequency are determined. It is possible to set the second predetermined value for the frequency, compare the pixel value with the first predetermined value, and compare the spatial frequency with the second predetermined value.

The first predetermined value is processed by software so that the brightness of the superimposed region is the same as that of the other regions, for example, in a state where a white image is output by each of the two projectors PJ1 and PJ2, In this state, when the pixel value is further lowered gradually, a pixel value that causes black floating in image processing by software is defined as a “first predetermined value”. Such processing for obtaining the first predetermined value may be performed for each RGB.
The second predetermined value can be experimentally set by projecting images having various spatial frequencies by the projectors PJ1 and PJ2.

And when the average value of the pixel value in each pixel of the image data corresponding to the projection image is higher than the first predetermined value, it is determined that the projection image is an image having a high pixel value, and the average value of the pixel values Is less than or equal to the first predetermined value, the projection image is determined to be an image having a low pixel value.
Similarly, the spatial frequency can be considered. When the spatial frequency of the image data corresponding to the projection image is higher than the second predetermined value, it is determined that the projection image is an image having a high spatial frequency, and the image When the spatial frequency of the data is equal to or lower than the second predetermined value, the projection image is determined to be an image having a low spatial frequency.
Note that the method for setting the first predetermined value and the second predetermined value is not limited to the above-described method, and the pixel value and the spatial frequency are determined using the first predetermined value and the second predetermined value. The method of performing is not limited to the method described above.

  Then, the light amount adjustment degree setting unit 103 determines the degree of light amount adjustment by the light shielding devices S1 to S4 and the degree of light amount adjustment by the image processing unit 102 according to the characteristics of the projection image, that is, the pixel value of the projection image and the spatial frequency. Set.

  Specifically, as a result of determining the characteristics of the projection image, it is determined that the projection value is a projection image whose pixel value is equal to or less than a first predetermined value (for example, a dark image such as a night scene), or the pixel value is the first predetermined value. If it is determined that the projection image is higher than the value and the spatial frequency is higher than the second predetermined value (for example, a bright image such as a field and a large amount of color change), the pixel value is higher than the first predetermined value. The amount of light whose degree of optical light amount adjustment by the light shielding devices S1 to S4 is higher than that of a projected image having a frequency equal to or lower than a second predetermined value (for example, a bright image with little color change such as the sky or snowy field spreading all over). Make adjustments.

  The optical light amount adjustment by the light shielding devices S1 to S4 is performed by performing control as described in FIGS. 4 and 5 on the light shielding plates (see FIGS. 2 and 3) included in the respective light shielding devices S1 to S4. It is possible to adjust the amount of light in the overlapping area. In addition to optical light amount adjustment by the light shielding devices S1 to S4, software light amount adjustment by the image processing unit 102 is supplementarily performed as necessary. The software-based light amount adjustment by the image processing unit 102 refers to image data (image data used for driving a light modulation element such as a liquid crystal panel or a mirror device in the projector) corresponding to a projected image by the image processing unit 102. In particular, the pixel value of the image data corresponding to the overlapping area is adjusted. In this case, for example, when the light amount adjustment by the light shielding devices S1 to S4 is insufficient (even if the light amount adjustment by the light shielding devices S1 to S4 is performed, the brightness of the overlapping region is brighter than the brightness of the other regions), the necessary amount The pixel value of the image data only needs to be lowered, and conversely, the light amount adjustment by the light shielding devices S1 to S4 is excessive (the result of the light amount adjustment by the light shielding devices S1 to S4 is If it is darker than the brightness of the area, the pixel value of the image data may be increased by a necessary amount.

  Depending on the content of the projection image, etc., there may be a case where a good light amount adjustment can be performed only by the light amount adjustment by the light shielding devices S1 to S4 without performing the software light amount adjustment by the image processing unit 102. In addition to adjusting the amount of light in the overlapping area, it is preferable to correct luminance differences and color unevenness of the four projectors PJ1 to PJ4. This image correction is performed by acquiring the correction parameters stored in the correction parameter storage unit 112.

  On the other hand, as a result of determining the characteristics of the projected image, a projected image whose pixel value is higher than the first predetermined value and whose spatial frequency is equal to or lower than the second predetermined value (for example, an image that is bright and has little color change such as the sky or snowy field spreading all over. ), The projected value is lower than the first predetermined value (for example, a dark image such as a night view) or the pixel value is higher than the first predetermined value and the spatial frequency is higher than the second predetermined value. The degree of light amount adjustment by the light shielding devices S1 to S4 is set lower than that of a projected image (for example, a bright image such as a field and a large amount of color change), and the degree of software light amount adjustment by the image processing unit 102 is increased. The light amount adjustment process is performed.

  Depending on the content of the projected image, etc., there may be a case where a good light amount adjustment can be performed only by software light amount adjustment by the image processing unit 102 without performing optical light amount adjustment by the light shielding devices S1 to S4. Also in this case, it is preferable to correct the luminance difference and color unevenness of the four projectors PJ1 to PJ4 in addition to the adjustment of the light amount in the overlapping area.

  Further, the control amount for each light shielding plate when driving each light shielding plate (see FIGS. 2 and 3) is performed by the correction parameter stored in the correction parameter storage unit 112. For example, the amount of movement of each light shielding plate (see FIGS. 2 and 3) in each light shielding device S1 to S4 is set in a plurality of stages, and the light amount adjustment degree setting unit 103 responds to the characteristics of the projected image. Then, a corresponding movement amount is acquired from the correction parameter storage unit 112, and a control signal corresponding to the acquired movement amount is given to the light shielding devices S1 to S4. The light shielding devices S <b> 1 to S <b> 4 drive the light shielding plate to be controlled based on the control signal received from the light amount adjustment degree setting unit 103. Further, the movement amount may be set not continuously but continuously.

  As described above, in the embodiment of the present invention, the degree of light amount adjustment by the light shielding devices S1 to S4 and the degree of light amount adjustment by the image processing unit 102 are set according to the characteristics of the projection image. For example, when it is determined that the projected image is a dark image with a low pixel value or an image with a high pixel value and a high spatial frequency, the light amount adjustment with a high degree of optical light amount adjustment by the light shielding devices S1 to S4 is performed. Do. On the other hand, when it is determined that the projected image is an image with a high pixel value and a low spatial frequency, the degree of optical light amount adjustment by the light shielding devices S1 to S4 is set low, and the image processing unit 102 performs software-like processing. The amount of light adjustment is increased to increase the amount of light.

  Note that when setting the degree of optical light amount adjustment by the light shielding devices S1 to S4 and the degree of software light amount adjustment by the image processing unit 102, the degree of light amount adjustment by the light shielding devices S1 to S4 is set high. Even if there is a case where the degree of light amount adjustment by the image processing unit 102 is set high, first, the light amount is adjusted according to the light amount adjustment degree set for the light shielding devices S1 to S4, and then Therefore, it is preferable to perform light amount adjustment by the image processing unit 102.

  As described above, the degree of optical light amount adjustment by the light shielding devices S1 to S4 and the degree of software light amount adjustment by the image processing unit 102 are set according to the characteristics of the projected image, thereby adjusting the light amount of the overlapping region. Can be appropriately performed according to the characteristics of the image to be projected, and the brightness of the superimposed area and other areas can be made inconspicuous regardless of the characteristics of the projected image. In particular, it has been found that a remarkable effect can be obtained in a multi-projection system that can display a large screen by arranging a large number of projectors in the vertical and horizontal directions.

  In a multi-projection system that constitutes such a large screen, for example, the pixel value and the spatial frequency are both high in the right part of the screen, and the spatial frequency is low even if the pixel value is high in the left part of the screen. As described above, the characteristics (pixel value and height of spatial frequency) of the projected image are often different depending on the position in the screen when projected onto the screen.

  Accordingly, in such a multi-projection system capable of displaying a large screen, it is preferable to perform the light amount adjustment processing described so far in correspondence with a plurality of positions in the screen. As a result, the overlapping area can be made inconspicuous in the entire screen.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, when image data analysis corresponding to a projection image is performed, it is also possible to weight the image data corresponding to the projection image around the overlap region and the overlap region and analyze the weighted image data. . In this case, for example, the difference between the pixel value of each pixel in the image data corresponding to the projection image and the first predetermined value is obtained, and the obtained difference is weighted.

  As the weighting at this time, when the weighting value (referred to as a weighting coefficient) in the overlapping area is set to “1.0”, the weighting coefficient is set to “1.0” according to the distance from the predetermined position of the overlapping area. Is also a small value. Then, the difference between the pixel value in each pixel of the image data corresponding to the projection image and the first predetermined value is multiplied by a weighting coefficient to obtain a weighted difference (referred to as weighting difference), and the weighted difference in each pixel in the projection image is calculated. An average value is obtained, and the characteristics of the projected image are determined by a predetermined calculation formula using the obtained average value and the first predetermined value.

  In this way, by weighting the image data corresponding to the superimposed region and the projection image around the superimposed region, and analyzing the weighted image data, the image data corresponding to the superimposed region and the surrounding projected image Therefore, the characteristics of the projected image determined by this can appropriately represent the characteristics of the projected image in the superimposed region.

  In the above-described embodiment, the average value of the pixel values in each pixel of the image data corresponding to the projection image is compared with the first predetermined value to determine the characteristics of the projection image. In addition, the difference between the pixel value of each pixel in the image data corresponding to the projection image and the first predetermined value described above is obtained, and the difference in each pixel of the projection image (in this case, weighting is not considered. It is also possible to determine the characteristics of the projected image using a predetermined calculation formula using the average value of “1.0” and the first predetermined value.

  In the above-described embodiment, the light shielding device having the movable light shielding plate is used as the light shielding means for optically adjusting the light amount. However, the electrochromic that can change the light transmittance as the light shielding plate. It is also possible to use glass, a translucent plate whose light transmittance is not 0, or a light shielding plate whose light transmittance changes with gradation. As the light-shielding plate whose light transmittance changes with gradation, a light-shielding plate having a low light transmittance on the side for adjusting the light amount at the end of the projected image and a light transmittance increasing toward the center of the projected image is preferable.

  FIG. 7 is a diagram showing an example of adjusting the light amount in the overlapping region when electrochromic glass or the like is used as the light shielding plate. As shown in FIG. 7, the light transmittance of the light shielding plates 11a and 21a using electrochromic glass or the like is shown. Is set to a predetermined light transmittance, the light amount of the overlapping region can be set to a predetermined light amount. Thus, by using electrochromic glass or the like that can change the light transmittance as the light shielding plate, the light amount of the overlapping region can be adjusted within a predetermined range without changing the position of the light shielding plate.

  When the projection image is a moving image, the image data analysis unit 101 preferably determines the characteristics of the projection image for each frame of the image data corresponding to the projection image. As described above, when the projection image is a moving image, it is possible to determine the characteristics of the projection image according to the change of the scene by determining the characteristics of the projection image for each frame, and thereby the overlap region The amount of light can be adjusted following the changes in the scene.

  In the above-described embodiment, the image data analysis unit 101 analyzes the image data and determines the characteristics of the projection image based on the analysis result. However, the image data to be projected is the projection image as described above. You may have the data which show the characteristic of these.

  It is also possible to determine in advance whether the light amount adjustment mainly by the light shielding plate or the light amount adjustment by image processing is mainly based on the content of the projected image. Here, “mainly adjusting the amount of light” means increasing the influence on the light amount adjustment of the overlapping region compared to the other. For example, in the case of an image in which black characters and line drawings are mostly white on a white background, such as a presentation image, a good image can be obtained by mainly adjusting the amount of light by software by the image processing unit 102. Therefore, when projecting such an image, the light amount adjustment by the light shielding devices S1 to S4 and the light amount adjustment by the image processing unit 102 are performed so that the software light amount adjustment by the image processing unit 102 is mainly performed. Is set in advance.

  On the other hand, when most of the images are dark or bright but have a high spatial frequency, it is better to focus on optical light quantity adjustment using a light-shielding device. , The degree of light amount adjustment by the light shielding devices S1 to S4 and the degree of light amount adjustment by the image processing unit 102 are set in advance so that the optical light amount adjustment by the light shielding devices S1 to S4 is mainly performed. .

  In the above-described embodiment, the light amount adjustment control device 200 including the image data analysis unit 101, the image processing unit 102, the light amount adjustment degree setting unit 103, and the like has been described as an example performed by an information processing device such as a personal computer. The light quantity adjustment control device 200 can also be configured as each projector has.

  In the above-described embodiment, the number of projectors constituting the multi-projection system is described as an example in which the number of projectors is two in the horizontal direction and the vertical direction, for the sake of simplicity. The multi-projection system of the invention enables a large screen display by arranging a large number of projectors in the horizontal and vertical directions.

  In the above-described embodiment, the rear projection type multi-projection system has been described as an example. However, the present invention can also be applied to a front projection type multi-projection system.

FIG. 2 is a diagram schematically showing the arrangement of projectors in the multi-projection system according to the embodiment of the invention. The figure which shows typically an example of the light-shielding apparatus used for the multi-projection system which concerns on embodiment. The figure explaining the motion of the light-shielding plates 11a and 11b of the light-shielding device S1 among the light-shielding devices S1 to S4 shown in FIG. The figure which shows the example which changes the light-shielding range of a superimposition area | region by changing the position of the light-shielding plate of each light-shielding apparatus provided corresponding to two adjacent projectors. The figure which shows the change of the light quantity in the superimposition area | region by changing the position of a light-shielding plate. The figure explaining the function of the multi-projection system which concerns on embodiment of this invention. The figure which shows the light quantity adjustment example of the superimposition area | region at the time of using electrochromic glass as a light-shielding plate.

Explanation of symbols

  11a, 21a, 31a, 41a ... vertical light shielding plate, 11b, 21b, 31b, 41b ... horizontal light shielding plate, 100 ... light amount adjustment device for overlapping area, 101 ... image data analysis unit, 102 ... image processing unit, DESCRIPTION OF SYMBOLS 103 ... Light quantity adjustment degree setting part 200 ... Light quantity adjustment control apparatus, PJ1-PJ4 ... Projector, SCR ... Screen, S1-S4 ... Light-shielding device.

Claims (10)

Light amount adjustment of a superimposing region used in a multi-projection system that projects a projection image from the plurality of projectors on a screen so that a superimposing region is formed between projection images projected from adjacent projectors among the plurality of projectors A device,
An image data analysis unit that analyzes image data used to generate the projection image and determines characteristics of the projection image;
A light-shielding device that optically adjusts the amount of light in the overlapping region;
An image processing unit that performs light amount adjustment of the superimposed region by image processing on the image data;
A light amount adjustment degree setting unit that sets the degree of light amount adjustment by the light shielding device and the degree of light amount adjustment by the image processing unit according to the characteristics of the projection image determined by the image data analysis unit;
A device for adjusting the amount of light in a superposed region, comprising: The light amount adjusting device for the overlapping area according to claim 1,
The image data analysis unit weights image data corresponding to the superimposed region and a projection image around the superimposed region, and analyzes the weighted image data, and adjusts the light amount of the superimposed region apparatus. In the amount adjustment device of the superposition field according to claim 1 or 2,
When the projection image is a moving image, the image data analysis unit determines a characteristic of the projection image for each frame of the image data. In the amount adjustment device of the superposition field according to any one of claims 1 to 3,
The apparatus for adjusting a light amount of a superimposed region, wherein the image data analysis unit determines a pixel value and a spatial frequency level of the image data as characteristics of the projection image. In the light amount adjustment apparatus of the superimposition area | region of Claim 4,
The light amount adjustment degree setting unit
For a projection image having a pixel value equal to or lower than the first predetermined value or a projection image having a pixel value higher than the first predetermined value and a spatial frequency higher than the second predetermined value, the pixel value is higher than the first predetermined value and the spatial frequency. Is higher than the projection image of the second predetermined value or less, the degree of light amount adjustment by the light shielding device,
For a projected image having a pixel value higher than the first predetermined value and a spatial frequency equal to or lower than the second predetermined value, a projected image or pixel value having a pixel value equal to or lower than the first predetermined value is higher than the first predetermined value. A light amount adjusting device for an overlapping region, characterized in that a degree of light amount adjustment by the image processing unit is made higher than that of a projected image having a spatial frequency higher than the second predetermined value. In the overlapping region light amount adjusting device according to any one of claims 1 to 5,
The light shielding device is provided for each projector, and has a movable light shielding plate capable of shielding a part of projection light from the corresponding projector with a predetermined light transmittance, and the position of the movable light shielding plate is determined. A light amount adjustment device for a superimposition region, wherein the light amount adjustment of the superposition region is performed by changing the light amount. In the overlapping region light amount adjusting device according to any one of claims 1 to 5,
The light-shielding device includes a light-shielding plate that is provided for each projector and can change the light transmittance within a predetermined range with respect to part of the projection light from the corresponding projector, and the light transmittance of the light-shielding plate The light amount adjustment device for the overlapping region is characterized in that the light amount adjustment of the overlapping region is performed by changing. Light amount adjustment of a superimposing region used in a multi-projection system that projects a projection image from the plurality of projectors on a screen so that a superimposing region is formed between projection images projected from adjacent projectors among the plurality of projectors A method,
An analysis step of analyzing the image data used to generate the projection image and determining characteristics of the projection image;
The degree to which the light amount adjustment of the superimposition area is optically performed by a light shielding device and the degree to which the light amount adjustment of the superposition area is performed by image processing on the image data are determined according to the characteristics of the projection image determined in the analysis step. Setting steps to set,
A method for adjusting the amount of light in an overlapping region, comprising: A plurality of projectors arranged so that a superimposed region is formed between projection images projected from adjacent projectors;
An image data analysis unit that analyzes image data used to generate the projection image and determines characteristics of the projection image;
A light-shielding device that optically adjusts the amount of light in the overlapping region;
An image processing unit that performs light amount adjustment of the superimposed region by image processing on the image data;
A light amount adjustment degree setting unit that sets the degree of light amount adjustment by the light shielding device and the degree of light amount adjustment by the image processing unit according to the characteristics of the projection image determined by the image data analysis unit;
A multi-projection system comprising: A light amount used in a multi-projection system having a plurality of projectors arranged so that a superimposed region is formed between projection images projected from adjacent projectors, and a light shielding device that optically adjusts the light amount of the superimposed region An adjustment control device,
An image data analysis unit that analyzes image data used to generate the projection image and determines characteristics of the projection image;
An image processing unit that performs light amount adjustment of the superimposed region by image processing on the image data;
A light amount adjustment degree setting unit that sets the degree of light amount adjustment by the light shielding device and the degree of light amount adjustment by the image processing unit according to the characteristics of the projection image determined by the image data analysis unit;
A light quantity adjustment control device characterized by comprising: