JP2003315914A - Multi-projection system and image adjustment method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the photographing time of a test image on a measuring camera in an adjustment work. <P>SOLUTION: In a multi-projection system which realize one image without joints by performing projection having overlap areas on a screen 100 by 12 projectors 101 to 112, a projection pattern which does not allow a test image generated in a test image generation part 160 to be simultaneously projected from adjacent projectors, by an image signal switching part 170 is generated at the time of adjustment, and the projected test image is photographed and analyzed by a measuring camera 120 to obtain projected image information of individual projectors. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen adjusting method for a multi-projection system, and more particularly to a screen adjusting method for a multi-projection system capable of adjusting the screen in a short time.

[0002]

2. Description of the Related Art In recent years, as a development of a large-scale projection device for projecting on a screen by a conventional projector having a large amount of light, a multi-projector for projecting an image on a screen from a plurality of projectors and displaying it as a single image. Projection systems have become widely known.

In this multi-projection system, a plurality of projected images are stitched together on a screen to
Since it is a single image, the following measures are required.

First, it is necessary to correct the distortion of each projected image. This distortion is not only the projection angle of the projected image, that is, the distortion caused geometrically and optically, but also the distortion peculiar to the projector due to the lens distortion. . As a method of correcting this distortion, there are a method of setting the installation position of the projector so that the projected image is not distorted, and a method of giving distortion to the original image in advance to cancel the distortion generated in the projected image. But,
In either method, a means for accurately detecting the distortion generated in the projected image is required, and a method using a measurement camera or a sensor embedded in the screen is known.

Second, although it is necessary to correct the brightness and color of each projected image, the projected image from the projector is affected by the light emitting state of the lamp and the characteristics of the spectroscope to a large extent, and therefore the same image signal is obtained. Even if input, the brightness and color of each projected image will not be the same. Therefore, a method has been proposed in which a test image projected from a projector onto a screen is photographed by a measurement camera and the brightness and color of the image projected from each projector are corrected.

Thirdly, it is necessary to join the projected images, and for this joining, an area that overlaps the adjacent projected images is provided in advance, and the brightness of the image in this area is changed stepwise. A blending process has been proposed in which the blending process is performed by changing the values. In order to realize this blending process, a method has been proposed in which a measurement camera is used as a means for extracting image information of an overlap area.

The above-mentioned first to third processes are generally called screen adjustment work, and are carried out at the time of installing the multi-projection system and at the time of replacement of the lamp when the influence of aged deterioration of the lamp occurs.

As this screen adjustment work, for example, as described in Japanese Patent Laid-Open No. 2001-166377, a test image is projected from all projectors at the same time and the image is taken.

[0009]

Generally, since the characteristics of the liquid crystal plate and the lens used in the projector are different in each projector, even if the same test image is input to the projector and projected, it is caused by the difference in the individual liquid crystal plates. Since the image distortion caused by the color unevenness, the brightness unevenness, and the difference in the characteristics of the lenses cannot be avoided, the same projected image cannot be obtained even with the same test image. The liquid crystal plate individual difference and the lens characteristic difference occur during the manufacturing process of the liquid crystal plate and the lens.
It is difficult to predict uneven brightness and image distortion.

The color unevenness, the brightness unevenness, and the image distortion can be recognized only by projecting a test image and photographing the test image, and the minimum unit is one pixel constituting the liquid crystal plate. Therefore, if the test image cannot be recognized on a pixel-by-pixel basis, color unevenness, brightness unevenness, and image distortion cannot be corrected.

Therefore, the inventors decided to project test images in a time series from individual projectors in order to strictly carry out image pickup in units of one pixel.

This method is disclosed in Japanese Patent Laid-Open No. 2001-166377.
Compared with the method of projecting a test image at the same time with all the projectors described in Japanese Patent Publication, when two adjacent projection images are projected at the same time, two images are mixed in the overlap area, so that the individual images are taken from the shooting results. Although it is difficult to extract information, there is no overlap area with adjacent images, so all pixels are not affected by other images, and there is the advantage that they can be taken independently. Image processing can now be performed on a pixel-by-pixel basis for each projector, and color irregularity, brightness irregularity, and image distortion can now be corrected on a pixel-by-pixel basis.

However, the number of projectors has increased with the recent increase in scale of multi-projection systems,
The adjustment method of projecting the projectors one by one in a time series causes a problem that the time required for the adjustment becomes long.

It is a first object of the present invention to provide a multi-projection system and a screen adjusting method for the same which can shorten the time taken for taking a test image by a measuring camera in the adjusting work.

[0015]

In order to achieve the above object, a multi-screen system of the present invention comprises a plurality of projectors installed on the back of the screen, a measurement camera installed in front of the screen, An image processing unit connected to the measurement camera, a seamless processing unit connected to the image processing unit, a video reproduction unit corresponding to each projector connected to the seamless processing unit, and a connection to the video reproduction unit A synchronized control unit, and an image signal switching unit connected to the projector while switching between the seamless processing unit and the test image generating unit connected to the seamless processing unit and the test image generating unit; At the time of adjustment, the test signal generating unit is switched to connect the test image generating unit and the projector by the image signal switching unit. And performing sequential measurements to calibrate the monitor at the same time sequentially projected to the measurement camera to the screen independent images of a plurality of the projectors in a non-interfering with each other by the control signal sequentially transmitted.

In addition, the screen adjusting method of the multi-projection system is switched so that a plurality of projectors installed on the back of the screen and the test image generating section are connected, and signals from the test image generating section do not interfere with each other. The process of simultaneously projecting independent images on the screen with the plurality of projectors and measuring with the measurement camera installed in front of the screen is repeated until all the installed projectors are measured. It is characterized by

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of the multi-projection system of this embodiment.

As shown in FIG. 1, the multi-projection system includes, for example, twelve projectors 101 to 112 installed on the back surface of one screen 100 and a measurement camera 120 installed in front of the screen 100.
And the image processing unit 121 connected to the measurement camera 120.
And the seamless processing unit 1 connected to the image processing unit 121.
50, 12 video reproduction units 131 to 142 connected to the seamless processing unit 150, and video reproduction units 131 to 1
42 is connected to the synchronization control unit 130, the test image generation unit 160, and the seamless processing unit 150, switches between the test image generation unit 160 and the seamless processing unit 150, and the twelve projectors 101 to 11 are connected.
2 is connected to the image signal switching unit 170.

The images projected from the twelve projectors 101 to 112, which are image projecting means, are joined together on the transmissive screen 100 to be displayed as one image. As described above, the multi-projection system is a system in which images are projected from a plurality of projectors onto the back surface of a transmissive screen and are connected on the screen to be displayed as one image. The image projected on the screen 100 is the screen 100.
Measurement camera 120 as a photographing means installed in front of
Taken in. The captured image is sent to the image processing unit 121 via a digital communication unit such as IEEE1394. The correction data of the video signal processed by the image processing unit 121 is sent to the seamless processing unit 150 as digital data.

In the seamless processing section 150, correction processing based on the correction data received from the image processing section 121 is applied to the video signals from the video reproducing sections 131 to 142 in real time, and the projectors 101 to 112 project the image and screen. A seamless image is displayed on 100. In order to display one seamless image on the screen, it is necessary to synchronize the video frames generated by the video reproduction units 131 to 142, and the synchronization control unit 130 generates the video reproduction units 131 to 142. The synchronization of the video frames is ensured.

On the other hand, in the screen adjustment work, the image signal switching unit 170 is switched, the connection between the seamless processing unit 150 and the projectors 101 to 112 is cut off, and the video signals from the video reproducing units 131 to 142 are turned off. The image generation unit 160 is connected to the projectors 101 to 112, and the adjustment test image generated by the test image generation unit 160 is displayed on the screen 10 via the image signal switching unit 170.
Project to 0.

Next, the operation of the thus configured multi-projection system will be described. When adjusting the screen, the image signal switching unit 170 is switched so that the test image generating unit 160 is connected to the projectors 101 to 101.
A test image generated by the test image generating unit 160 by connecting to the projector 112 is projected by the twelve projectors 101 to 112 and displayed on the screen 100. At this time, the adjacent projection images from the projectors 101 to 112 are projected so as to have an overlap area as shown in FIG.

For example, the projected image of the projector 101 and the projected image of the projector 102, the projected image of the projector 105 and the projected image of the projector 106, and the projected image of the projector 109 and the projected image of the projector 110 overlap in the overlap area 201. Further, the projected image of the projector 102 and the projected image of the projector 103, the projected image of the projector 106 and the projector 1
The projection image of 07, the projection image of the projector 110, and the projection image of the projector 111 overlap the overlap area 2.
It overlaps with 02. Similarly, the projected images of other adjacent projectors are overlapped with each other in the overlap region 20 shown in FIG.
1 to 205, the projected images at the four corners have two overlapping areas, the projected images located on the sides of the screen 100 have three overlapping areas, and the projected image at the center of the screen 100 has four overlapping areas. Overlapping in one overlap area. As described above, in the first stage of the screen adjustment work, adjustment is performed so that an overlap area is formed on each projection screen.

Next, processing is performed according to the flow chart shown in FIG. In step 211, test images are projected from projectors in odd rows and columns. Where odd rows,
For the sake of convenience, the odd-numbered column is defined by defining the leftmost column as the first column and the uppermost column as the first row. In this definition, as shown in FIG.
A test image is simultaneously projected on the screen 100 from four projectors 3, 109 and 111.

By projecting the test image in this way, as shown in FIG.
Two projected images are projected. In step 212, these four projected images are measured once by the measurement camera 120 and image-processed, so that the projectors 101, 103, 1
The same information as when the projection image is measured by the measurement camera 120 is obtained by projecting each of 09 and 111 in time series. Information on the test image in pixel units obtained by image processing is stored as correction data for color unevenness, brightness unevenness, and image distortion.

As described above, in steps 211 and 212, the four projection images are measured once by the measurement camera 120 and image processing is performed, so that the projectors 101, 103 and 1 are processed.
Compared to the conventional method of performing four processes of projecting and measuring 09 and 111 in time series, the processing can be completed in a processing time of a quarter or less. Here, the case where the measurement camera 120 continuously measures a plurality of times is also referred to as one measurement.

In steps 213 and 214, similarly, the four projectors 10 in odd rows and even columns shown in FIG.
The test images are projected from the screens 2, 104, 110, 112 simultaneously onto the screen 100, and the measurement camera 120 measures the image once to process the image. Yes, steps 215 and 216
Then, the test images are simultaneously projected from the two projectors 105 and 107 onto the screen 100, and the measurement camera 12
Since the measurement is performed once at 0 and the image processing is performed, it can be completed in half the time or less as compared with the case of time-series imaging. Similarly, in steps 217 and 218, the two projectors 106,
Since a test image is simultaneously projected from the screen 108 onto the screen 100 and measured once by the measurement camera 120, and image processing is performed, it can be completed in half the time or less compared to the case of shooting in time series. By this processing procedure, it is possible to complete the projection of the test image from all projectors onto the screen 100 and the measurement by the measurement camera 120.

As described above, since the measurement of the 12 projectors is completed by measuring the measurement camera 120 four times, the time required for measuring the 12 projectors 12 times in a time series is one-third or less. You can complete the measurement with.

Further, by projecting the projection images from a plurality of projectors at the same time so that adjacent projection images do not overlap each other in the overlapping area, each projector can project one projection image at a time. It is possible to perform the image pickup in units of 1 pixel, and the adjustment work time can be shortened by shortening the image pickup time.

FIG. 6 is a flowchart of an image projection pattern different from the image projection pattern shown in the flowchart of FIG. In this example, in step 221, as shown in FIG.
A test image is simultaneously projected on the screen 100 from four projectors 2, 104, 110 and 112. Similarly, in steps 223 and 224, the four projectors 101, 103 and 10 in the odd rows and the odd columns shown in FIG.
Simultaneously projecting test images from the screens 9 and 111 onto the screen 100, the measurement camera 120 measures once, and image processing is performed.
Then, in steps 225 and 226, the two projectors 10 are connected.
Simultaneously projecting a test image from 6, 108 on the screen 100, measuring it once with the measurement camera 120, and processing the image,
In steps 227 and 228, the two projectors 10
Simultaneously projecting test images from the screens 5 and 107 onto the screen 100, the measurement camera 120 measures once, and image processing is performed.

As described above, even in the flow shown in FIG. 6, the number of times of photographing can be completed by four times of steps 212, 214, 216, and 218, which is 1/3 as compared with the case of measuring 12 projectors 12 times in time series. It can be completed in the following time.

When projecting test images from four projectors simultaneously in an odd number of rows and odd columns with nine projectors of three units in the vertical direction and three units in the horizontal direction, four of the nine units in total project at the same time. The ratio is the highest at 4/9, and in the state shown in FIGS. 4 and 5, it is 1/3 in 4 out of 12 projectors. As the number of projectors increases, this ratio will increase to 4
Asymptotic to 1 / min.

[0033]

According to the present invention, it is possible to project a plurality of test images at the same time and obtain image information of each projector, so that the adjustment work time can be shortened.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a multi-projection system according to an embodiment of the present invention.

FIG. 2 is a plan view showing a positional relationship between projected images.

FIG. 3 is a flowchart showing processing of a projection method.

FIG. 4 is a plan view showing an example of a projection method.

FIG. 5 is a plan view showing an example of a projection method.

FIG. 6 is a flowchart showing processing of a projection method.

[Explanation of symbols]

100 ... Screen, 101-112 ... Projector,
120 ... Measurement camera, 121 ... Image processing unit, 130 ... Synchronization control unit, 131-142 ... Video reproducing unit, 150 ... Seamless processing unit, 160 ... Test image generating unit, 170 ... Image signal switching unit, 201-205 ... Over Lap area.

Continued front page    (72) Inventor Shigeru Naoi             5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture             Information Control Systems Division, Hitachi, Ltd.             Within F term (reference) 2K103 AA05 AA17 AA18 AA25 AB05                       AB06 AB08 AB10 CA03 CA38                       CA54 CA69

Claims (3)

[Claims] 1. A plurality of projectors installed on the back of a screen, a measurement camera installed in front of the screen, an image processing unit connected to the measurement camera, and an image processing unit connected to the image processing unit. A seamless processing unit, a video reproduction unit corresponding to each of the projectors connected to the seamless processing unit, a synchronization control unit connected to the video reproduction unit, a seamless processing unit and a test image generation unit, and A seamless processing unit and a test image generation unit are switched, and an image signal switching unit connected to the projector is provided, and the test image generation unit and the projector are connected by the image signal switching unit when the screen is adjusted. Switching between the test image generating section and the control signals sequentially transmitted from the test image generating section, the independent images that are non-interfering with each other are projected to the plurality of the project images. Multi-projection system and performing sequential measurements to calibrate the monitor the measurement camera simultaneously sequentially projected on the screen in. 2. A plurality of projectors installed on the rear surface of the screen and a test image generating section are switched to be connected to each other, and a plurality of the projectors form independent images without interference with each other by a signal from the test image generating section. In the multi-projection system, the screen adjustment is repeated until all of the installed projectors are measured by simultaneously projecting on the screen and measuring with a measurement camera installed in front of the screen. Screen adjustment method. 3. A plurality of projectors installed on the back surface of the screen and a test image generating section are switched to be connected to each other, and adjacent projection images are overlapped with each other in an overlapping area by a signal from the test image generating section. To prevent this, the process of simultaneously projecting projection images from multiple projectors onto the screen and measuring with a measurement camera installed in front of the screen is repeated until all of the installed projectors are measured. A method for adjusting the screen of a multi-projection system, which is characterized by performing