JP2010224277A - Image display system, imaging means, and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display system for displaying images having proper brightness without adjusting it on a projector side. <P>SOLUTION: This image display system 1 includes a camera 2 for imaging an object, acquiring image information, and transmitting the obtained image information and a projector 3 for receiving the image information transmitted by the camera 2 and displaying the image based on the received image information. The camera 2 includes an image acquiring part 21 for acquiring the image information, a correction information receiving part 22 for receiving the correction information for correcting the image information, an image correction part 23 for correcting the image information based on the received correction information, and an image transmission part 24 for transmitting the corrected image information to the projector 3. The projector 3 includes an image receiving part 35 for receiving the image information transmitted by the image transmission part 24, a correction information computing part 372 for computing the correction information based on the received image information, and a correction information transmission part 36 for transmitting the computed correction information to the camera 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image display system, imaging means, and a projector.

Conventionally, an imaging unit that captures an image of a subject to acquire image information, transmits the acquired image information, and a projector that receives the image information transmitted by the imaging unit and displays an image based on the received image information. An image display system provided is known (for example, see Patent Document 1).
The electronic camera system (image display system) described in Patent Document 1 includes an electronic camera (imaging means) and a projector, and displays an image captured by the electronic camera on the projector.

  By the way, in recent years, inexpensive cameras such as a web camera capable of capturing an image of a subject to acquire image information and transmitting the acquired image information via an interface such as a USB (Universal Serial Bus) are known. . Thus, it is conceivable to configure an image display system that displays an image captured by the camera on the projector by connecting such a camera to the projector via an interface such as a USB.

JP 2007-102078 A

However, in an inexpensive camera such as a web camera, since the exposure is often fixed, there is a problem that when an image captured by the camera is displayed on the projector, an image with appropriate brightness cannot be displayed. .
Further, although it is conceivable to correct image information on the projector side in order to display an image with appropriate brightness, there is a problem that the range of brightness that can be adjusted by the user of the projector is narrowed.

  An object of the present invention is to provide an image display system, an imaging unit, and a projector that can display an image with appropriate brightness without adjustment on the projector side.

  The image display system of the present invention captures an image of a subject to acquire image information, transmits the acquired image information, receives the image information transmitted by the imaging unit, and based on the received image information An image display system including a projector that displays an image, wherein the imaging unit includes an image acquisition unit that acquires the image information, and correction information for correcting the image information acquired by the image acquisition unit. Based on the correction information received by the correction information receiving unit, the correction information receiving unit, the image correcting unit for correcting the image information, and the image information corrected by the image correcting unit to the projector An image transmission unit that transmits the image information, the image reception unit that receives the image information transmitted by the image transmission unit, and the image information that is received by the image reception unit. Zui and a correction information calculating unit that calculates the correction information, characterized by comprising a correction information transmitting unit for transmitting the correction information calculated by the correction information calculation unit in the imaging unit.

According to such a configuration, the imaging unit corrects the image information acquired by imaging the subject based on the correction information received by the correction information receiving unit, and transmits the corrected image information to the projector. Further, the projector calculates correction information for correcting the image information based on the image information transmitted by the imaging unit, and transmits the calculated correction information to the imaging unit.
Therefore, even when an inexpensive camera such as a web camera is employed as the imaging unit, the imaging unit can correct the image information based on the correction information calculated on the projector side. That is, the image display system can display an image with appropriate brightness without adjustment on the projector side.

  In the present invention, the projector includes a request transmission unit that transmits request information for requesting transmission of the image information to the imaging unit, and the image acquisition unit transmits the request transmitted by the request transmission unit. It is preferable to acquire the image information of one frame when the information is received.

  According to such a configuration, the image acquisition unit of the imaging unit acquires one frame of image information by transmitting the request information from the request transmission unit of the projector. Therefore, the imaging unit and the projector are synchronized with each other. Image information can be corrected. Therefore, the image display system can reliably display an image with appropriate brightness without adjustment on the projector side.

  In the present invention, the projector includes an average value calculating unit that calculates an average value of luminances of all pixels in one frame of image information received by the image receiving unit, and an average calculated by the average value calculating unit. A storage unit that stores a value for each frame, and the correction information calculation unit changes the average value calculated by the average value calculation unit and the average value of the previous frame stored in the storage unit. It is preferable to calculate the correction information when the amount is larger than a predetermined threshold.

Here, if the correction information for correcting the image information for each frame is calculated and the image information is corrected, the image displayed by the projector changes in appearance for each frame, so it is difficult to see. There is a problem.
According to the present invention, when the amount of change in image information between frames is small, the correction information calculation unit does not calculate correction information for correcting the image information, so that the image displayed on the projector is easy to see. be able to.

The imaging unit of the present invention captures an image of a subject to acquire image information, transmits the acquired image information, receives the image information transmitted by the imaging unit, and an image based on the received image information An image acquisition unit used in an image display system including a projector for displaying image information, the image acquisition unit acquiring the image information, and correction information for correcting the image information acquired by the image acquisition unit A correction information receiving unit that performs correction, an image correction unit that corrects the image information based on the correction information received by the correction information receiving unit, and image information that has been corrected by the image correction unit. And an image transmission unit.
According to such a configuration, the same operational effects as those of the image display system described above can be achieved.

The projector according to the present invention captures a subject to acquire image information, transmits the acquired image information, receives the image information transmitted by the imaging unit, and receives an image based on the received image information. A projector used in an image display system including a projector to display, based on an image receiving unit that receives image information transmitted by the imaging unit, and image information received by the image receiving unit, A correction information calculation unit that calculates the correction information, and a correction information transmission unit that transmits the correction information calculated by the correction information calculation unit to the imaging unit.
According to such a configuration, the same operational effects as those of the image display system described above can be achieved.

1 is a block diagram showing a schematic configuration of an image display system according to a first embodiment of the present invention. 3 is a flowchart showing control processing of the image display system in the embodiment. The block diagram which shows schematic structure of the image display system which concerns on 2nd Embodiment of this invention. 3 is a flowchart showing control processing of the image display system in the embodiment.

[First Embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
[Schematic configuration of image display system]
FIG. 1 is a block diagram showing a schematic configuration of an image display system 1 according to the first embodiment of the present invention.
As shown in FIG. 1, the image display system 1 captures a subject to acquire image information, receives a camera 2 as an imaging unit that transmits the acquired image information, and receives image information transmitted by the camera 2. The projector 3 displays an image based on the received image information on the screen Sc, the camera 2, and the transmission unit 4 such as a USB interface that connects the projector 3 and enables information transmission.

  The camera 2 receives the request information for requesting transmission of the image information, acquires an image information of one frame when the request information is received, and corrects the image information acquired by the image acquisition unit 21 The correction information receiving unit 22 that receives the correction information, the image correction unit 23 that corrects the image information based on the correction information received by the correction information receiving unit 22, and the image information that is corrected by the image correction unit 23 And an image transmission unit 24 that transmits the image to the projector 3 via the transmission unit 4. Note that the image information is acquired by the image acquisition unit 21 as 8-bit RGB (Red Green Blue) image information, and the request information and the correction information are transmitted from the projector 3 via the transmission unit 4.

The projector 3 includes an image projection unit 31 and a control unit 32.
The image projection means 31 changes the arrangement of liquid crystal molecules enclosed in a liquid crystal cell (not shown) based on a drive signal from the light source device 312 having the light source lamp 311 that emits light and the control means 32, A transmission type liquid crystal panel 313 that modulates the light emitted from the lamp 311 in accordance with image information to form an optical image and emits the light, and the optical image emitted from the liquid crystal panel 313 is displayed on the screen Sc. A projection optical device 314 that magnifies and projects toward the screen. Thereby, an image based on the image information is displayed on the screen Sc.

  Although not shown, the image projection unit 31 includes three liquid crystal panels 313 corresponding to three colors of RGB. The light source device 312 includes a color light separation optical system that separates light emitted from the light source lamp 311 into three colors of light. Further, the projection optical device 314 has a combining optical system that generates an optical image representing a color image by combining three color optical images. In addition, about the structure of such an optical system, the structure of the optical system of various general projectors can be utilized.

The control means 32 includes, for example, a CPU and controls the projector 3 as a whole. The control means 32 is a main memory 33 that stores programs, data, and the like, and request information for requesting transmission of image information. 2 through the transmission unit 4, the image reception unit 35 that receives and decodes the image information transmitted by the image transmission unit 24 through the transmission unit 4, and the image reception unit. The correction information transmission part 36 which transmits the correction information calculated based on the image information received in 35 to the camera 2 via the transmission means 4 and the image processing part 37 are provided.
These components 33 to 37 are connected by a bus (not shown) so that necessary information can be transmitted.

The image processing unit 37 includes, for example, a GPU (Graphics Processor Unit) and performs image processing, and includes a frame memory 371 and a correction information calculation unit 372.
The frame memory 371 stores image information received by the image receiving unit 35. The image reception unit 35 can receive image information transmitted from the camera 2 and can receive image information via an external input terminal such as a video input terminal, for example. Then, the image processing unit 37 generates a drive signal based on the image information stored in the frame memory 371 and outputs the generated drive signal to the image projection unit 31.
The correction information calculation unit 372 calculates correction information based on the image information stored in the frame memory 371, that is, the image information received by the image reception unit 35. Further, the correction information calculation unit 372 stores the calculated correction information in the main memory 33.

[Control processing of image display system]
Next, control processing of the image display system 1 will be described with reference to FIG.
FIG. 2 is a flowchart showing the control process of the image display system 1.
In FIG. 2, the camera 2 executes steps S21 to S24 in the left flowchart, and the projector 3 executes steps S31 to S33 in the right flowchart.

When the control process of the image display system 1 is executed, the request transmission unit 34 and the correction information transmission unit 36 of the projector 3 transmit the request information and the correction information stored in the main memory 33 to the camera 2 via the transmission unit 4. (S31: information transmission step). The initial value of the correction information is stored in the main memory 33 immediately after the control process of the image display system 1 is executed.
When the request information and the correction information are transmitted to the camera 2 in the information transmission step S31, the image acquisition unit 21 and the correction information reception unit 22 of the camera 2 receive the request information and the correction information transmitted from the projector 3. Receive (S21: information reception step).

When the request information and the correction information are received in the information reception step S21, the image acquisition unit 21 of the camera 2 acquires one frame of image information (S22: image information acquisition step).
When the image information is acquired in the image information acquisition step S22, the image correction unit 23 of the camera 2 corrects the image information based on the correction information received in the information reception step S21 (S23: Image information correction). Step).
When the image information is corrected in the image information correction step S23, the image transmission unit 24 of the camera 2 transmits the corrected image information to the projector 3 (S24: image transmission step).

When the image information is transmitted in the image transmission step S24, the camera 2 executes the information reception step S21 again. The image receiving unit 35 of the projector 3 receives the transmitted image information (S32: image receiving step).
When the image information is received in the image receiving step S32, the correction information calculation unit 372 calculates correction information based on the received image information, and stores the calculated correction information in the main memory 33 (S33: Correction information calculation step).
When the correction information is calculated in the correction information calculation step S33, the projector 3 executes the information transmission step S31 again.

  Here, the correction information calculation unit 372 acquires a predetermined feature amount in the image information, and calculates correction information based on the acquired feature amount. For example, the correction information calculation unit 372 can calculate the correction information using the following formulas (1) and (2) using the lowest luminance and the highest luminance in the image information as the feature amount.

In the equations (1) and (2), the offset (Offset) and the gain (Gain) of the correction information are calculated with the lowest luminance in the image information as BP and the highest luminance as WP. Further, since the image information is acquired by the image acquisition unit 21 as 8-bit RGB (Red Green Blue) image information, the numerator is 255 in the expression (2).
Furthermore, the luminance in the image information for calculating BP and WP can be calculated by any one of the following formulas (3-1) to (3-3).

Note that V in Formula (3-1) is the luminance in the HSV color system, Yc in Formula (3-2) is the luminance in the YCbCr color system, and Yp in Formula (3-3) is This is the luminance in the YPbPr color system. Max is a function that returns the maximum value.
Then, the image correction unit 23 corrects the image information by applying the offset and gain calculated by the above formulas (1) and (2) to the formulas (4-1) to (4-3). be able to.

  R ′, G ′, and B ′ are RGB values after correction, and mid is a function that returns a median value.

The image display system 1 according to the present embodiment has the following effects.
(1) The camera 2 can correct the image information based on the correction information calculated on the projector 3 side. Therefore, even when an inexpensive camera such as a web camera is adopted as the camera 2, the image display system 1 can display an image with appropriate brightness without adjustment on the projector 3 side.
(2) Since the image acquisition unit 21 of the camera 2 acquires one frame of image information when the request information is transmitted by the request transmission unit 34 of the projector 3, the camera 2 and the projector 3 are synchronized with each other. Information can be corrected. Therefore, the image display system 1 can reliably display an image with appropriate brightness without performing adjustment on the projector 3 side.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 3 is a block diagram showing a schematic configuration of an image display system 1A according to the second embodiment of the present invention.
In the following description, parts that have already been described are assigned the same reference numerals and description thereof is omitted.
In the first embodiment, the image display system 1 includes the correction information calculation unit 372, and the correction information calculation unit 372 calculates correction information for each frame. In contrast, in the present embodiment, the image display system 1A includes a main memory 33A, a correction information calculation unit 372A, and an average value calculation unit 373, as shown in FIG. The difference is that correction information is not calculated when the amount of change in image information between frames is small.

The average value calculation unit 373 calculates the average value of the luminance of all the pixels in one frame of image information received by the image reception unit 35.
The main memory 33A as a storage unit stores the average value calculated by the average value calculation unit 373 for each frame.
The correction information calculation unit 372A calculates correction information when the average value calculated by the average value calculation unit 373 and the amount of change in the average value of the previous frame stored in the main memory 33A are larger than a predetermined threshold. To do.

Next, control processing of the image display system 1A will be described with reference to FIG.
FIG. 4 is a flowchart showing a control process of the image display system 1A.
In FIG. 4, the camera 2 executes steps S21 to S24 in the left flowchart, and the projector 3 executes steps S31 to S33 in the right flowchart.

When the image information is received in the image reception step S32, the average value calculation unit 373 calculates the average value of the luminance of all the pixels in the image information (S321: average value calculation step).
When the average value is calculated in the average value calculation step S321, the correction information calculation unit 372A calculates the average value calculated by the average value calculation unit 373 and the average value of the previous frame stored in the main memory 33A. It is determined whether or not the amount of change is larger than a predetermined threshold (S322: determination step). Thereafter, the projector 3 stores the calculated average value in the main memory 33A for each frame.
Then, when it is determined in the determination step S322 that the change amount of the average value is equal to or less than the predetermined threshold value, the projector 3 executes the information transmission step S31 again.

In addition, when it is determined in the determination step S322 that the change amount of the average value is larger than the predetermined threshold, the correction information calculation unit 372A calculates the correction information based on the image information received in the image reception step S32. The calculated correction information is stored in the main memory 33A (S33: correction information calculation step).
When the correction information is calculated in the correction information calculation step S33, the projector 3 executes the information transmission step S31 again.

In this embodiment as well, the same actions and effects as in the first embodiment can be obtained, and the following actions and effects can be obtained.
(3) Since the correction information calculation unit 372A does not calculate the correction information when the change amount of the image information between frames is small, the image displayed on the projector 3 can be easily viewed.

[Modification of Embodiment]
Note that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope in which the object of the present invention can be achieved are included in the present invention.
For example, in each of the embodiments described above, the projector 3 includes the request transmission unit 34, and the camera 2 and the projector 3 correct the image information synchronously. However, the correction may be performed asynchronously. In short, it is sufficient that the imaging unit can correct the image information based on the correction information calculated on the projector side.
In each of the embodiments described above, the correction information calculation units 372 and 372A calculate the correction information using the lowest luminance and the highest luminance in the image information as the feature amount, but calculate the correction information based on other feature amounts. May be.

In each of the embodiments, the projector 3 includes the three liquid crystal panels 313. However, the projector 3 may be configured as a projector including two liquid crystal panels or a projector including four or more liquid crystal panels.
In each of the above embodiments, the transmissive liquid crystal panel 313 is employed. However, the present invention is not limited to this, and a reflective liquid crystal panel may be employed, or a digital micromirror device (DMD) may be employed. Good. DMD is a trademark of Texas Instruments Incorporated.

  The present invention can be suitably used for an image display system, an imaging unit, and a projector.

  DESCRIPTION OF SYMBOLS 1,1A ... Image display system, 2 ... Camera (imaging means), 3 ... Projector, 21 ... Image acquisition part, 22 ... Correction information receiving part, 23 ... Image correction part, 24 ... Image transmission part, 33A ... Main memory ( Storage unit), 34 ... request transmission unit, 35 ... image reception unit, 36 ... correction information transmission unit, 372, 372A ... correction information calculation unit, 373 ... average value calculation unit.

Claims (5)

An imaging unit that images a subject to acquire image information, transmits the acquired image information, and a projector that receives the image information transmitted by the imaging unit and displays an image based on the received image information. An image display system,
The imaging means includes
An image acquisition unit for acquiring the image information;
A correction information receiving unit that receives correction information for correcting the image information acquired by the image acquisition unit;
An image correcting unit for correcting the image information based on the correction information received by the correction information receiving unit;
An image transmission unit that transmits image information corrected by the image correction unit to the projector;
The projector is
An image receiving unit for receiving the image information transmitted by the image transmitting unit;
A correction information calculation unit that calculates the correction information based on image information received by the image reception unit;
An image display system, comprising: a correction information transmission unit that transmits the correction information calculated by the correction information calculation unit to the imaging unit. The image display system according to claim 1,
The projector is
A request transmission unit that transmits request information for requesting transmission of the image information to the imaging unit;
The image acquisition unit acquires one frame of the image information when the request information transmitted by the request transmission unit is received. The image display system according to claim 2,
The projector is
An average value calculating unit for calculating an average value of luminance of all pixels in one frame of image information received by the image receiving unit;
A storage unit that stores the average value calculated by the average value calculation unit for each frame;
The correction information calculation unit calculates the correction information when the average value calculated by the average value calculation unit and the amount of change in the average value of the previous frame stored in the storage unit are larger than a predetermined threshold. An image display system characterized by calculating. An imaging unit that images a subject to acquire image information, transmits the acquired image information, and a projector that receives the image information transmitted by the imaging unit and displays an image based on the received image information. An imaging means used in an image display system,
An image acquisition unit for acquiring the image information;
A correction information receiving unit that receives correction information for correcting the image information acquired by the image acquisition unit;
An image correcting unit for correcting the image information based on the correction information received by the correction information receiving unit;
An image pickup means comprising: an image transmission unit that transmits image information corrected by the image correction unit to the projector. An imaging unit that images a subject to acquire image information, transmits the acquired image information, and a projector that receives the image information transmitted by the imaging unit and displays an image based on the received image information. A projector used in an image display system,
An image receiving unit for receiving image information transmitted by the imaging means;
A correction information calculation unit that calculates the correction information based on image information received by the image reception unit;
A projector comprising: a correction information transmission unit that transmits correction information calculated by the correction information calculation unit to the imaging unit.

Images