JP2015225101A - Image projection device, method for controlling image projection device, and program for controlling image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of leakage light by preventing projection light from an image projection device from projecting from a screen, regardless of the shape of the screen.SOLUTION: The image projection device includes a camera 103 which is provided to image the screen, a calibration pattern projection control part 110 which projects a calibration pattern onto the screen, a calibration pattern imaging and projecting part 111 which allows the camera 103 to image the calibration pattern projected on the screen, a leakage determination part 112 which compares the image data of the calibration pattern imaged by the camera 103 with a stored calibration pattern and detects a leakage area where the projection light is not projected on the screen, and a correction image projection part 113 which projects an image onto the screen, so that the image is not projected onto the screen of a part corresponding to the leakage area detected by the leakage determination part 112.

Description

  The present invention relates to an image projection apparatus, a control method for the image projection apparatus, and a control program for the image projection apparatus. More specifically, the present invention relates to correction control of a projection image of the image projection apparatus.

  In recent years, the chances of giving presentations using a huge screen to a large number of people at lectures and educational sites have increased remarkably. In particular, a projector widely known as an image projecting apparatus has been improved in the resolution and the cost reduction due to the higher resolution of the liquid crystal panel, the higher efficiency of the light source lamp. In addition, for example, small and light image projecting apparatuses using DMD (Digital Micro-mirror Device) are widely used, and these image projecting apparatuses are widely used not only in offices and schools but also in homes.

  Regarding the correction of the projection image in such an image projection apparatus, the image projection apparatus has an imaging unit that captures the projection image, and based on the image captured by the imaging unit, a technique for correcting the projection image such as trapezoidal distortion correction It has been known.

  For example, in Patent Document 1, a measurement pattern having a predetermined shape and an L-shaped black region are superimposed and output to a liquid crystal panel, a pattern is detected from the captured pattern image, and a screen frame in the pattern image is detected. Coordinate conversion for detecting straight lines based on the image and converting the camera coordinates in the captured image to panel coordinates based on the panel coordinate values of the pattern and the camera coordinate values of the pattern detected from the pattern image Disclosed is an image processing apparatus that calculates a coefficient, calculates a vertex of a screen frame in panel coordinates based on a straight line detected for each corner and a coordinate conversion coefficient, calculates a correction value, and corrects a trapezoidal distortion. Yes.

  In the correction of a projected image in Patent Document 1, a screen frame is virtually assumed using a built-in camera, and image processing is performed so that an image fits in the virtual screen frame. More specifically, a calibration pattern image (referred to as a calibration pattern) is projected onto the screen, the calibration pattern is captured by the built-in camera, the screen frame is virtually detected from the captured calibration pattern information, and the virtual screen frame The projected image is corrected so that it fits inside.

  However, in a method that virtually assumes a screen frame, for example, when a part of the screen is missing, depending on the shape of the screen, the image corrected image does not completely fit in the screen, and a part of the projected image May protrude from the screen frame.

  If a part of the projected image protrudes from the screen frame, a part of the projection light from the image projection device will be transmitted to the back side of the screen (referred to as leakage light) and will be in the vicinity of the screen or near the screen Leaked light is projected on a person who passes through the door, causing uncomfortable feelings.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image projection apparatus capable of suppressing the occurrence of leakage light by preventing projection light from the image projection apparatus from protruding from the screen regardless of the shape of the screen.

  In order to achieve such an object, an image projection apparatus according to the present invention includes an imaging unit provided so as to be capable of imaging a projection surface, a pattern image projection unit that projects a pattern image on the projection surface, and a projection onto the projection surface. The pattern image capturing unit that captures the pattern image being captured by the image capturing unit, the image data of the pattern image captured by the image capturing unit, and the stored pattern image are compared, and the projection light is projected onto the projection surface. Leak determination means for detecting a leak area that has not been performed, and correction image projection for projecting an image on a projection surface so that an image is not projected on a non-projection surface corresponding to the leak area detected by the leak determination means Means.

  According to the present invention, the generation of leakage light can be suppressed by preventing the projection light from the image projection apparatus from protruding from the screen regardless of the shape of the screen.

It is a schematic block diagram which shows an example of an image projection system. It is a block diagram which shows the structure of an image projection apparatus. (A) Grid-shaped calibration pattern, (B) Calibration pattern in which circles are arranged in a grid pattern. It is explanatory drawing which shows the state by which the calibration pattern was projected on the screen (no chip | tip). It is explanatory drawing which shows the state by which the calibration pattern was projected on the screen (with a chip). It is an image figure which shows the state which cut the lattice pattern of the part which detected the leak area | region. It is explanatory drawing which shows the example of the projection image after a leak determination. It is a flowchart of the image correction control by an image projection apparatus.

  Hereinafter, the configuration according to the present invention will be described in detail based on the embodiment shown in FIGS.

  The image projection apparatus (image projection apparatus 100) according to the present embodiment has an imaging means (camera 103) provided so as to be able to image a projection surface (screen 200), and a pattern image (calibration pattern 205) on the projection surface. Pattern image projection means (calibration pattern projection control unit 110) to be projected, pattern image imaging means (calibration pattern imaging control unit 111) for imaging the pattern image projected on the projection surface by the imaging means, and imaging by the imaging means A leak determination means (leak determination unit 112) that compares the image data of the pattern image and the stored pattern image and detects a leak region (leak region 201) where the projection light is not projected onto the projection surface; The correction image for projecting the image on the projection surface so that the image is not projected on the non-projection surface of the portion corresponding to the leakage area detected by the leakage determination means. Projecting means (the corrected image projection section 113), but with a. In addition, the code | symbol in embodiment and an application example are shown in a parenthesis.

(Configuration of image projection system)
FIG. 1 is a schematic configuration diagram illustrating an example of an image projection system 300. The image projection system 300 includes an image projection device (projector) 100 and a video supply device 150, and the image projection device 100 and the video supply device 150 are connected by a cable 160.

  The image projection device 100 is an image output device that projects an image provided by the video supply device 150 onto a projection surface such as the screen 200. In addition, the image projection apparatus 100 projects an OSD screen (superimposed image) such as a menu screen on which the user can specify various operations together with the image provided by the video supply device 150.

  The image projection apparatus 100 has, as an interface for inputting a video signal, a VGA (Video Graphics Array) input terminal such as a D-Sub connector, an HDMI (registered trademark) (High-Definition Multimedia Interface) terminal, an RGB terminal, a DisplayPort terminal, an S An input terminal such as a VIDEO terminal or an RCA terminal is provided, and a video signal, an audio signal, or the like is received from the video supply device 150 via a cable 160 connected to these terminals. Note that the image projection apparatus 100 may receive a video signal from the video supply apparatus 150 by wireless communication based on a wireless communication protocol such as Bluetooth (registered trademark) or WiFi (registered trademark).

  The video supply device 150 is a device that provides an image to be projected by the image projection device 100. The video supply device 150 includes an interface that outputs a video signal, and the video signal forming the display image of the video supply device 150 is an image projection device at a predetermined transfer rate (for example, 30 fps (frame per second) to 60 fps). To 100.

  Similarly, the video supply device 150 includes an output terminal such as a VGA output terminal or an HDMI terminal as an interface for outputting a video signal, and transmits the image signal to the image projection device 100 via a cable 160 connected to these terminals. Can do. Note that the video supply device 150 may transmit a video signal to the image projection device 100 by wireless communication.

  As the video supply device 150, for example, a notebook type PC (information processing device) can be used. In addition, a device capable of supplying a video signal such as a desktop PC, a tablet PC, a PDA, a DVD player, or a Blu-ray disc player can be applied. In the example illustrated in FIG. 1, one image supply device 150 is connected to the image projection device 100, but the image projection device 100 can connect two or more image supply devices 150. In addition, a plurality of image projection apparatuses 100 are connected to one video supply apparatus 150, images are projected onto different projection areas on the screen 200, and a single image is projected by combining the projected images. A multi-projection system may be used.

  The image projection apparatus 100 includes a camera 103 as an imaging unit and an illumination optical system 108, and projects a projection image 202 on a screen 200 indicated by a dotted line. The screen 200 shown in FIG. 1 has a shape in which a part of the upper left part and the lower right part are missing. A solid line arrow 108a shown in FIG. 1 represents an optical path of projection light from the illumination optical system 108.

  In addition, the field of view by the camera 103 included in the image projection apparatus 100 is assumed to be at least larger than the area where the projection image 202 is projected. Therefore, the entire area of the projection image 202 can be captured by the camera 103.

  Here, an area shown in gray in the projection image 202 (hereinafter referred to as a leakage area 201) is such that the projection image 202 (that is, the projection light) from the image projection apparatus 100 transmits the area lacking the screen 200 to the back side. It represents the state of being. That is, the leakage area 201 is a leakage light generation area where leakage light from the screen 200 is generated.

  If a person or the like passes behind the screen 200 in a state where such a leak region 201 is generated, the projection light may enter the eyes of the person and cause discomfort.

  Thus, the image projection apparatus 100 according to the present embodiment prevents the occurrence of this leakage light, and the position of the leakage region 201 where leakage light is generated in the projection image 202 by the camera 103 as described below. By suppressing the light in the region, it is possible to prevent the projection light from hitting a person on the other side of the screen 200.

(Configuration of image projection device)
FIG. 2 is a block diagram illustrating a configuration of the image projection apparatus 100 according to the present embodiment.

  The image projection apparatus 100 includes an input interface unit 101, an image processing circuit 102, a camera 103, a camera control circuit 104, a main control unit 105, an operation unit 106, an illumination optical system drive circuit 107, and an illumination optical system. 108.

  The input interface unit 101 is a terminal unit that is connected to a video supply device 150 that supplies an image to the image projection device 100 with a cable 160. As described above, an HDMI terminal or the like is provided to receive a video signal and an audio signal.

  The image processing circuit 102 converts an input video signal or the like into predetermined video data (for example, RGB digital video data), and transfers the converted video data to the main control unit 105.

  Here, the main control unit 105 transmits and receives control signals to and from the above-described units, and also includes a CPU (Central Processing Unit) that is a main processor, various control programs, and calibration images for image correction (calibration). ROM (Read Only Memory) storing pattern 205), a memory device (eg, SDRAM (Synchronous Dynamic Random Access Memory) etc.) that temporarily stores data in each process, and setting information even when the power is turned off NVRAM (Non Volatile RAM) or the like, which is a data holding memory device for recording, etc. is connected by a bus.

  The main control unit 105 also controls a calibration pattern projection control unit 110 that projects the calibration pattern 205 onto the screen 200 and a calibration pattern that controls the camera control circuit 104 and images the calibration pattern projected onto the screen 200 by the camera 103. A leakage determination unit 112 that detects a leakage region 201 that is not projected on the screen 200 in the projection image 202 based on the imaging control unit 111 and the imaging data of the calibration pattern captured by the camera 103, and the leakage determination unit 112 And a corrected image projecting unit 113 for projecting the corrected projected image 202 onto the screen 200 so as not to cause screen leakage based on the determination result.

  The main control unit 105 also controls the illumination optical system driving circuit 107 to display the video data transferred from the image processing circuit 102.

  The illumination optical system drive circuit 107 projects the projection image 202 by controlling the illumination optical system 108 based on the control from the main control unit 105. The illumination optical system 108 includes a liquid crystal light valve, a color wheel, a DMD, and the like, a mirror (reflection optical system) that reflects image light for displaying an image and an image on the screen 200, and a lens (projection optics) for enlarging / reducing. System).

  The operation unit 106 receives various operation requests from the user, and includes key buttons (main body keys) provided on the outer surface of the image projection apparatus 100. When receiving the operation request, the operation unit 106 notifies the main control unit 105 of the operation request. Further, the operation unit 106 receives an operation signal from a remote controller that is a remote operation device, and notifies the main control unit 105 of the operation signal.

  The main body and the remote control are provided with a power key for turning on / off the power of the image projection apparatus 100, a menu key for performing various settings, a cross key, a determination key, an input key for switching an input signal, adjusting a volume, and the like. Note that video data at the time of various settings and input switching is formed by OSD processing by the main control unit 105.

  The camera 103 is an imaging unit that is controlled by the camera control circuit 104 and can image at least the entire area of the screen 200 on which the projection image 202 is projected. For example, it is provided on the projection lens side surface of the image projection apparatus 100 and photographs the front of the image projection apparatus 100. Image data captured by the camera 103 is sent from the camera control circuit 104 to the main control unit 105.

(Projection and imaging of calibration pattern)
The calibration pattern projection by the calibration pattern projection control unit 110 will be described with reference to FIGS.

  The calibration pattern projection control unit 110 of the image projection apparatus 100 according to the present embodiment projects the calibration pattern 205 stored in the main control unit 105 onto the screen 200.

  The calibration pattern is a pattern image in which images of the same shape are arranged in a grid pattern. For example, a calibration pattern in a grid pattern in which white and colored rectangles are arranged in a grid pattern as shown in FIG. A calibration pattern in which circles as shown in FIG. 3B are arranged in a grid pattern can be used. Such a calibration pattern is generally capable of detecting distortion of an image projected by comparison with an image obtained by capturing the calibration pattern.

  4 and 5 are explanatory diagrams showing a state when the calibration pattern 205 is projected from the image projection apparatus 100 onto the screen 200. FIG.

  In the example shown in FIG. 4, the screen 200 has a substantially rectangular shape, and all the calibration patterns 205 are projected onto the screen 200, and no light leaks from the screen 200.

  On the other hand, in the example shown in FIG. 5, the screen 200 has a shape in which a part of the upper left part and the lower right part are missing. For this reason, a part of the calibration pattern 205 is not projected onto the screen 200, and the projection light has leaked from the upper left part and the lower right part.

  Next, the calibration pattern imaging control unit 111 of the image projection apparatus 100 controls the camera control circuit 104 and the camera 103 so that the screen 200 is imaged when the calibration pattern 205 is projected. Image data captured by the camera 103 is input to the main control unit 105 via the camera control circuit 104.

(Leakage determination)
When the imaging data of the calibration pattern is input to the main control unit 105, the leakage determination unit 112 compares the imaging data with the stored calibration pattern 205, thereby correcting the calibration projected on the screen 200. It is determined whether or not the pattern (projected image 202) is missing and which part is missing, and whether or not leaked light is generated.

  The comparison between the imaging data and the calibration pattern 205 may be performed by a known or new pattern matching method, and is not particularly limited, but the color information of the portion of the imaging data that has passed through the screen 200 (that is, the leakage region 201). (RGB or the like) is different from other parts and the stored calibration pattern 205, so that the projection image 202 is projected on the screen 200 based on the color information (RGB or the like) between the imaging data and the calibration pattern 205. What is necessary is just to detect the non-leakage area 201 and to detect the position of the leakage area 201.

  FIG. 6 is an image diagram showing a state in which the lattice pattern of the portion where the leakage region 201 is detected is cut in the leakage determination unit 112. FIG. 6 shows the result of determining the position of the leakage area 201 without the screen by the leakage determination unit 112 for the imaging data obtained by imaging the screen 200 shown in FIG.

  In the present embodiment, an example in which the detection of the leakage region 201 is performed in a grid unit (a rectangular unit in the case of FIG. 3A and a circular unit in the case of FIG. 3B) that forms a grid pattern will be described. When a part of the lattice pattern is missing, only the missing part may be detected as the leak region 201.

  Here, the resolution of the calibration pattern 205 and the captured image is desirably high. As a result, when there is even a portion (one pixel at a minimum) that is missing in one grid, the leakage determination unit 112 can determine that there is a screen leakage. Even when the projected image of the corresponding portion is cut and projected, the cut portion of the projected image 202 can be minimized.

(Projection of corrected image)
FIG. 7 is an explanatory diagram illustrating an example of a projection image 202 by the image projection apparatus 100 after leakage determination and image correction.

  The image projection apparatus 100 does not project an image for a portion corresponding to the position where the leakage region 201 is detected in the leakage determination unit 112. For this reason, the corrected image projection unit 113 of the main control unit 105 has corrected after cutting an image at a position corresponding to the leakage region 201 detected so as not to cause screen leakage based on the determination result of the leakage determination unit 112. The projected image 202 is projected onto the screen 200.

  As described above, by not projecting the image at the position corresponding to the leakage area 201, there is no area where the projection light projects the screen 200 as shown in FIG. That is, the entire projected image 202 is projected on the screen 200, and the occurrence of leakage light can be prevented.

  In addition, when the corrected image projection unit 113 detects that the leakage area 201 exists on the end side of the projection image 202, the correction image projection unit 113 replaces the portion corresponding to the leakage area 201 without projecting the leakage area 201. The entire image may be projected by performing a reduction process on the projection image 202 so as to avoid the position where the image becomes or by controlling the projection optical system.

  In addition, when the image projection apparatus 100 detects the leakage area 201 on the screen 200, the image projection apparatus 100 may be provided with a notification unit that notifies the user to that effect.

  Further, the mode setting means that allows the user to select whether or not to perform the detection of the leakage area 201 and the correction control of the image that does not project an image on the leakage area 201 described above by mode selection (screen leakage prevention mode on / off). It is also preferable to comprise.

(Image correction control flow)
FIG. 8 is a flowchart showing the entire image correction control executed by the image projection apparatus 100.

  First, when a power-on operation is performed, the image projection apparatus 100 is activated (S101), and the camera control circuit 104 activates the camera 103 (S102).

  Next, the main control unit 105 determines whether or not the screen leakage prevention mode is on (S103). If it is on (S103: YES), the calibration pattern projection control unit 110 displays the calibration pattern 205. Projecting on the screen 200 (S104).

  Next, the calibration pattern imaging control unit 111 captures the projected calibration pattern 205 with the camera 103 in a state where the calibration pattern 205 is projected on the screen 200 (S105).

  Next, the leak determination unit 112 determines whether the specified number of grids of the calibration pattern 205 matches the number of grids of the calibration pattern of the imaging data (S106). If the number of grids does not match, that is, if there is a leakage area 201 (S106: YES), it is determined which part is missing (S107).

  Thereafter, the corrected image projection unit 113 generates a corrected image in which a portion corresponding to the leakage region 201 is cut (S108), and projects the corrected image on the screen 200 (S109). If there is no leakage area 201 (S106: NO), the image is projected as it is (S109).

  According to the image projection apparatus 100 according to the present embodiment described above, regardless of the shape of the screen 200, for example, even when there is a minute missing portion on the end side of the screen 200, the image projection apparatus 100 The projection light does not protrude from the screen 200, and the occurrence of leakage light can be suppressed.

  Therefore, it is possible to prevent the leakage light from being projected on a person who is in the vicinity of the screen or passes through the vicinity of the screen, thereby causing discomfort.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

  The calibration pattern projection control unit 110, the calibration pattern imaging control unit 111, the leakage determination unit 112, and the corrected image projection unit 113 of the main control unit 105 are, for example, software (control program) executed by the CPU of the main control unit 105. ) Is executed by the image projection apparatus 100.

100 Image projection device (projector)
101 Input Interface Unit 102 Image Processing Circuit 103 Camera (Imaging Means)
104 camera control circuit 105 main control unit 106 operation unit 107 illumination optical system drive circuit 108 illumination optical system 110 calibration pattern projection control unit (pattern image projection means)
111 Calibration pattern imaging control unit (pattern image imaging means)
112 Leak determination unit (leak determination means)
113 corrected image projection unit (corrected image projection means)
150 Image supply device 160 Cable 200 Screen (projected surface)
201 Leakage area 202 Projected image 300 Image projection system

JP 2013-186332 A

Claims (8)

Imaging means provided so as to be capable of imaging the projection surface;
Pattern image projection means for projecting a pattern image onto a projection surface;
A pattern image imaging unit that causes the imaging unit to image a pattern image projected on the projection surface;
A leak determination unit that compares image data of a pattern image captured by the imaging unit with a stored pattern image, and detects a leak region in which the projection light is not projected on the projection surface;
Correction image projection means for projecting an image on the projection surface so that the image is not projected on the non-projection surface of the portion corresponding to the leakage area detected by the leakage determination means;
An image projection apparatus comprising: The pattern image is a pattern image in which images of the same shape are arranged in a grid pattern,
2. The image according to claim 1, wherein the leak determination unit detects the presence or absence of a leak region based on a comparison of the number of images having the same shape in the image data and the stored pattern image. Projection device.   The image projection apparatus according to claim 1, wherein the leakage determination unit detects a leakage region based on a comparison between color information of the image data and color information of the stored pattern image. .   The image projecting apparatus according to claim 1, wherein the corrected image projecting unit projects an image obtained by cutting an image corresponding to a leakage area.   The corrected image projecting means reduces the entire image so that the image is not projected onto the non-projection surface corresponding to the leakage area, and projects the reduced image. The image projection apparatus in any one of.   The image projection apparatus according to claim 1, further comprising a mode setting unit configured to set whether or not to perform leak correction and execution of image correction control based on detection of the leak area. A control method for an image projection apparatus comprising an imaging means provided so as to be capable of imaging a projection surface,
Pattern image projection processing for projecting a pattern image onto a projection surface;
A pattern image imaging process in which a pattern image projected on a projection surface is imaged by the imaging unit;
Leak determination processing for comparing the image data of the pattern image captured by the imaging unit and the stored pattern image, and detecting a leakage area in which the projection light is not projected on the projection surface;
Correction image projection processing for projecting an image on the projection surface so that the image is not projected on the non-projection surface of the portion corresponding to the leakage area detected in the leakage determination processing;
A control method for an image projection apparatus, characterized in that: A control program for an image projection apparatus comprising an imaging means provided so as to be capable of imaging a projection surface,
Pattern image projection processing for projecting a pattern image onto a projection surface;
A pattern image imaging process in which a pattern image projected on a projection surface is imaged by the imaging unit;
Leak determination processing for comparing the image data of the pattern image captured by the imaging unit and the stored pattern image, and detecting a leakage area in which the projection light is not projected on the projection surface;
Correction image projection processing for projecting an image on the projection surface so that the image is not projected on the non-projection surface of the portion corresponding to the leakage area detected in the leakage determination processing;
A program for controlling an image projection apparatus, characterized by causing a computer to execute the above.