JP2006086728A - Image output apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image output apparatus correcting a plurality of image signals per image signal. <P>SOLUTION: The apparatus has: a plurality of input terminals 101-104 for inputting images with individual image signals corresponding to a plurality of image signals, respectively; a plurality of correcting circuits 111, 112 for correcting images with a plurality of image signals; an image selection switch 110 provided between the plurality of input terminals and the plurality of correcting circuits for outputting each image with the image signal to a correcting circuit corresponding to the image signal, respectively; and a controller 56 for making each input terminal corresponding to a selected image signal in response to the image select switch corresponding to each corresponding correcting circuit upon the input of an instruction for selecting the image signal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image output device such as a CRT (Cathode-ray Tube), a liquid crystal display, and a projector.

  There is an image output device that can input a plurality of different image signals for each type of image and display a plurality of images based on the plurality of image signals on one screen (for example, Patent Document 1). This image output apparatus synthesizes and displays images based on a plurality of image signals input from devices such as a personal computer (hereinafter referred to as a personal computer), video and television.

  Formats for outputting a plurality of images in the display area of the image output apparatus include those called picture-in-picture (PIP) and picture-out-picture (POP). In PIP, one image is displayed on a main screen having the entire display area as a screen, a sub-screen smaller than the main screen is superimposed on a part of the main screen, and another image is displayed on the sub-screen. In POP, a main screen that is smaller than the entire display area is provided to display one image, and a sub-screen is arranged in the remaining display area so as not to overlap the main screen, and another image is displayed on the sub-screen. Let

  In general, the standard of a color space, which is a reference for expressing the color of an image with a numerical value, varies depending on the device. The standard used for personal computers is mainly sRGB, and the standard used for video and general television is NTSC. In addition, the standard used in HDTV (High Definition Television) called high-definition television is different from that of general television. Thus, when the color space standards are different, the color gamut, which is the range of colors that can be generated by the image output apparatus, is also different. The image output apparatus may receive an image having a color gamut different from the color gamut of the apparatus itself.

  An image output apparatus capable of executing PIP and POP output formats is configured to convert a plurality of images based on a plurality of image signals into one standard color gamut when a plurality of image signals of images having different color spaces are input. Color matrix conversion is performed uniquely, and a plurality of images in different color spaces are displayed in the same type of color space. This will be described in the case where two images are displayed in the display area.

  FIG. 3 is a diagram showing an example of image display by the image output apparatus, and shows a case where the output format of the image is PIP. As shown in FIG. 3, a main screen 201 is provided in the entire display area, and a sub screen 202 is arranged so as to overlap a quarter of the main screen 201. Assume that an image displayed on the main screen 201 is based on an NTSC standard image signal from a television, and a sub image displayed on the sub screen 202 is based on an sRGB standard image signal from a personal computer.

When correcting the colors of the images on the main screen 201 and the sub screen 202 shown in FIG. 3, the image output apparatus uses either of the NTSC profiles as a color space profile for converting the color gamut into the original standard. It is also used for signal correction. Since the image on the main screen 201 is corrected with the color space profile corresponding to the original input image, the image is the optimum image for color adjustment.
JP-A-10-333656

  When corrected as described above, the sub-screen image is corrected using the NTSC profile even though the color space of the original input image is the sRGB standard. Therefore, the sub-screen image is corrected in a different color space from the input image, and the saturation, hue, and the like are different from the original image.

  Further, when the screen is divided into a plurality of images such as four or nine images in the POP output format, all the images are corrected using the color space profile of any one of the image signals. Are corrected in the same color space. Therefore, optimal correction is performed for an image in the same color space as the profile used for correction, but saturation, hue, and the like are different from the original image in an image in a different color space.

  Although there is an image output device that can correct contrast and brightness for each image, it has no function for correcting the color space for each image.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide an image output apparatus capable of correcting a color space of a plurality of image signals for each image signal. And

In order to achieve the above object, an image output apparatus of the present invention comprises:
Corresponding to a plurality of image signals, a plurality of input terminals to which an image by each image signal is input,
A plurality of color space correction circuits for respectively correcting images by the plurality of image signals;
An image selection switch provided between the plurality of input terminals and the plurality of color space correction circuits, for outputting an image of each image signal to each color space correction circuit provided corresponding to each image signal;
When an instruction to select the image signal is input, a control unit that associates an input terminal corresponding to the selected image signal with respect to the image selection switch and a color space correction circuit;
It is the structure which has.

  In the present invention, a plurality of input terminals to which a plurality of image signals are input are provided, and when an image signal is selected, a color space correction circuit is associated with each image signal by the image selection switch.

  The image output apparatus of the present invention can correct the color space for each image based on the image signal when displaying a plurality of images in the display area based on the plurality of input image signals. Can be displayed as an image.

  The image output apparatus of the present invention is characterized in that a color space correction circuit for correcting the color space of the image corresponding to the image signal of the image to be combined is provided.

  The image output apparatus of the present invention will be described. In this embodiment, the image output apparatus is a projector. Assume that a composite image obtained by combining two images is displayed on the screen as in the main screen 201 and the sub screen 202 shown in FIG.

  FIG. 1 is a block diagram showing a configuration example of an image output apparatus according to the present invention.

  As shown in FIG. 1, the image output apparatus includes an input unit 50, a signal conversion unit 52, an image selection switch 110, correction circuits 111 and 112, and an image synthesis circuit for synthesizing two images into one. 117, a format conversion unit 118, a storage unit 54, a control unit 56, an operation unit 119 for a user to input an instruction, and a projection unit 60 that projects an image on a screen.

  The input unit 50 includes input terminals 101 to 104 for inputting an image signal from the outside corresponding to the image signal, and an input terminal selection switch 105 for selecting an input image signal. The input terminals 101 to 104 have a video terminal 101 for inputting a composite video signal, and an S video for inputting an S video signal obtained by separating the composite video signal into a Y (luminance) signal and a C (color) signal. There are a terminal 102 and analog RGB terminals 103 and 104 for inputting sRGB analog signals.

  The signal converter 52 includes video decoders 106 and 107 that convert video signals into digital RGB signals that are RGB digital signals, and A / D converters 108 and 109 that convert analog RGB signals into digital RGB signals. The video decoder 106 converts the composite video signal into a digital RGB signal. The video decoder 107 converts the S video signal into a digital RGB signal.

  The image selection switch 110 selects from the video decoders 106 and 107 and the A / D converters 108 and 109 a signal to be sent to the correction circuits 111 and 112 corresponding to the image signal selected by the input terminal selection switch 105.

  The storage unit 54 includes a FLASH ROM 121 for storing switch correspondence information, color space information, correction information, and screen setting information, and an SDRAM 122 for synchronizing projected images. The switch correspondence information is information in which each of the input terminals 101 to 104 is associated with each of the video decoders 106 and 107 and the A / D converters 108 and 109. The color space information is various color space profiles such as an NTSC profile, an sRGB profile, an HDTV profile, and a projector profile. The projector profile is a color space profile that matches the color gamut that the projector can display. Information on these color space profiles is stored in association with information on the input terminals 101 to 104. The color gamut of the projector is determined by the characteristics of the optical system (lens, light source, RGB filter, etc.) in the projection means 60, and is different from that of sRGB or NTSC. Therefore, in order to reproduce the color on the screen, it is necessary to convert it to a color gamut that can be displayed by the projector. The correction information includes saturation, hue, brightness, and contrast set values, and γ data 1 to 3 used for γ correction. The screen setting information includes information on the size and position of the sub screen. In the present embodiment, the size of the sub-screen is set to 1/2 times the vertical and horizontal sizes of the main screen that is the entire display area. Further, the position of the sub-screen is the address of the lower right quarter portion of the main screen, as in FIG.

  The correction circuit 111 includes a color space correction circuit 113 and an image correction circuit 114. The correction circuit 112 includes a color space correction circuit 115 and an image correction circuit 116. Since the correction circuit 111 and the correction circuit 112 have the same configuration, the configuration of the correction circuit 111 will be described.

  FIG. 2 is a block diagram showing an example of the configuration of the correction circuit 111.

  As shown in FIG. 2, the color space correction circuit 113 includes an RGB → XYZ conversion circuit 303, a saturation / hue conversion circuit 305, and an XYZ → RGB conversion circuit 306. When the RGB → XYZ conversion circuit 303 receives information of the color space profile 304 corresponding to the selected image signal and receives a digital RGB signal from the signal conversion unit 52, the RGB color system data is converted into the XYZ color system. In order to convert the digital RGB signal, the digital RGB signal is converted into an XYZ signal with reference to the color space profile 304. By converting RGB signals into XYZ signals, the saturation and hue settings can be changed. The saturation / hue conversion circuit 305 corrects the XYZ signal to the input saturation and hue setting values. When the XYZ → RGB conversion circuit 306 receives information of the projector profile 307 and receives the XYZ signal from the saturation / hue conversion circuit 305, the XYZ → RGB conversion circuit 306 returns the XYZ color system data to the RGB color system data. An XYZ signal is converted into a digital RGB signal with reference to the projector profile 307.

  In this way, the color space correction circuit 113 corrects the saturation and hue after changing from the RGB color system to the XYZ color system that is the tristimulus value, and subsequently, from the XYZ color system to the RGB color system. Returning to the system, the data is sent to the image correction circuit 114. The conversion method between the RGB color system and the XYZ color system is formulated by the CIE (Commission International d'Eclairage) and is the same as the conventional one. Omitted.

  The image correction circuit 114 includes a γ correction circuit 308 and a brightness / contrast correction circuit 310. When γ data 309 is input, the γ correction circuit 308 sets a γ value in the γ data 309. When the brightness / contrast correction circuit 310 is input with the set values of brightness and contrast, the brightness / contrast correction circuit 310 sets the brightness and contrast to the input set values.

  The control unit 56 includes a CPU 120 that executes predetermined processing according to a program, and a program memory 126 that stores the program. In this embodiment, the correction items are six items of color space profile, saturation, hue, γ, brightness, and contrast. Information on each correction item is stored in advance in the FLASH / ROM 121, but when the user operates the operation unit 119 to input these items, the control unit 56 stores information on each item stored in the FLASH / ROM 121. Update.

  When the user operates the operation unit 119 to select an image signal, selects an input terminal, and subsequently sets the screen type of the main screen or the sub-screen, the control unit 56 supports the FLASH / ROM 121 switch. With reference to the information, the input terminal selection switch 105 and the image selection switch 110 are switched according to the selected input terminal. Then, the screen type information indicating the type of the screen corresponding to the correction circuit 111 and the correction circuit 112 and the screen setting information stored in the FLASH / ROM 121 are transmitted to the image composition circuit 117. Further, the color space profile corresponding to the image signal input to the selected input terminal is read from the FLASH ROM 121 and transmitted to the RGB → XYZ conversion circuit 303. Also, the set values of saturation and hue are read from the FLASH ROM 121 and transmitted to the saturation / hue conversion circuit 305. Further, the projector profile 307 is transmitted to the XYZ → RGB conversion circuit 306. Also, the γ data 309 is read from the FLASH ROM 121 and transmitted to the γ correction circuit 308. Further, the brightness and contrast setting values are read from the FLASH ROM 121 and transmitted to the brightness / contrast correction circuit 310.

  When the image composition circuit 117 receives the image signals from the correction circuit 111 and the correction circuit 112, the image composition circuit 117 sets the images based on the two image signals to the main screen and the sub screen, respectively, according to the screen type information and the screen setting information. Then, according to the information on the size and position of the sub screen, the main screen 201 and the sub screen 202 are combined into one image as shown in FIG. Since the technique for combining and displaying two images is the same as that used in a conventional television or the like, a detailed description of the algorithm of the process itself is omitted.

  When the format conversion circuit 118 receives the composite image from the image composition circuit 117, the format conversion circuit 118 matches the output frequency of the apparatus itself and the RGB output timing, and transmits the composite image to the projection unit 60.

  Next, the operation procedure of the image output apparatus of this embodiment will be described. Here, it is assumed that a video image input to the video terminal 101 is displayed on the main screen, and an image from a personal computer input to the analog RGB terminal 103 is displayed on the sub-screen.

  When the user operates the operation unit 119 to select the video terminal 101 for the main screen and input an instruction to select the analog RGB terminal 103 for the sub screen, the control unit 56 refers to the switch correspondence information, The video terminal 101 is connected to the video decoder 106 with respect to the input terminal selection switch 105, and the analog RGB terminal 103 is connected to the A / D converter 108. Further, the output of the video decoder 106 is connected to the correction circuit 111 with respect to the image selection switch 110, and the output of the A / D converter 108 is connected to the correction circuit 112.

  Then, the control unit 56 reads the NTSC profile from the FLASH / ROM 121 and transmits it to the color space correction circuit 113, and reads the sRGB profile from the FLASH / ROM 121 and transmits it to the color space correction circuit 115. Further, the projector profile is read from the FLASH ROM 121 and transmitted to the color space correction circuits 113 and 115. Also, the γ data 309 is read from the FLASH ROM 121 and transmitted to the γ correction circuit 308, and the brightness and contrast setting values are read from the FLASH ROM 121 and transmitted to the brightness / contrast correction circuit 310. Further, the screen type information and the screen setting information read from the FLASH / ROM 121 are transmitted to the image composition circuit 117.

  When the video decoder 106 receives a video signal from the video terminal 101 via the input terminal selection switch 105, the video decoder 106 converts the video signal into a digital RGB signal. Then, the converted digital RGB signal is transmitted to the correction circuit 111 via the image selection switch 110. When the analog RGB signal is received from the analog RGB terminal 103 via the input terminal selection switch 105, the A / D converter 108 converts the analog RGB signal into a digital RGB signal. Then, the converted digital RGB signal is transmitted to the correction circuit 112 via the image selection switch 110.

  In the correction circuit 111, when the color space correction circuit 113 receives the digital RGB signal, the RGB → XYZ conversion circuit 303 converts the digital RGB signal into an XYZ signal using the sRGB profile, and the saturation / hue conversion circuit 305. Send to. When the saturation / hue conversion circuit 305 receives the XYZ signal from the RGB → XYZ conversion circuit 303, the saturation / hue conversion circuit 305 converts the saturation / hue setting values received via the control unit 56. Then, the converted XYZ signal is transmitted to the XYZ → RGB conversion circuit 306. The XYZ → RGB conversion circuit 306 converts the XYZ signal received from the saturation / hue conversion circuit 305 into a digital RGB signal using the projector profile 307. Subsequently, the converted digital RGB signal is transmitted to the image correction circuit 114.

  When receiving the digital RGB signal from the color space correction circuit 113, the γ correction circuit 308 of the image correction circuit 114 changes the γ value to the γ data 309 received via the control unit 56. Then, the digital RGB signal after γ correction is transmitted to the brightness / contrast correction circuit 310. When the brightness / contrast correction circuit 310 receives the digital RGB signal from the γ correction circuit 308, the brightness / contrast correction circuit 310 corrects the digital RGB signal to the brightness and contrast setting values received via the control unit 56, and the corrected digital RGB signal is corrected. It transmits to the image composition circuit 117.

  On the other hand, when the correction circuit 112 receives the digital RGB signal from the A / D converter 108 via the image selection switch 110, the correction circuit 112 performs color space correction and image correction on the data indicated by the signal in the same manner as the correction circuit 111 and performs correction. The digital RGB signal is transmitted to the image composition circuit 117.

  When the image synthesis circuit 117 receives the digital RGB signal as the main screen image signal from the correction circuit 111 and receives the digital RGB signal as the sub screen image signal from the correction circuit 112, the image synthesis circuit 117 converts the sub screen image into the vertical / Change to 1/2 times the horizontal size. Subsequently, in order to embed in the lower right of the main screen image, the reproduction image data is overwritten on the address of the lower right quarter of the data of the main screen image to create one composite image. In this way, the image composition circuit 117 makes the main screen and the sub screen one composite image. Then, the single composite image is transmitted to the format conversion circuit 118.

  When the format conversion circuit 118 receives the composite image from the image composition circuit 117, the format conversion circuit 118 transmits the composite image to the projection unit 60 by matching the output frequency and the RGB output timing. The projection unit 60 projects the composite image received from the format conversion circuit 118 on the screen.

  Thereafter, when the user operates the operation unit 119 to change the correction information, the control unit 56 transmits correction information corresponding to the changed content to the correction circuits 111 and 112. The correction circuits 111 and 112 correct the image in the same manner as described above corresponding to the correction information received from the control unit 56. Further, the control unit 56 updates the correction information stored in the FLASH / ROM 121 in accordance with the changed contents.

  As described above, the image output apparatus of the present invention includes a plurality of input terminals through which a plurality of image signals can be input, and when an image signal is selected, a color space correction circuit is associated with each image signal. Therefore, when a plurality of images are displayed in the display area based on a plurality of input image signals, the color space can be corrected for each image based on the image signals, and any image can be displayed as an optimum image.

  In addition, by performing color matrix conversion corresponding to the standard of the input image signal, each image signal is corrected in the color gamut of the original standard, so the color that matches the color space for the displayed image Correction can be performed. Therefore, each of the plurality of displayed images is a more optimal image.

  In this embodiment, the image output apparatus is a projector, but it may be a CRT or a liquid crystal display.

  When the RGB color system data is converted into XYZ color system data in the color space correction circuits 113 and 115, the digital RGB signal is first converted into the XYZ signal using the projector profile, and then the XYZ signal is converted. The signal may be converted to the original image standard such as NTSC or sRGB.

  Further, the signal input to the input unit 50 may be a digital signal. In this case, the signal output from the input terminal selection switch 105 is input to the image selection switch 110 as it is without passing through the signal converter 52.

  Furthermore, although the case where two correction circuits are provided has been described, there may be three or more according to the number of image signals to be combined.

It is a block diagram which shows the example of 1 structure of the image output device of this invention. It is a block diagram which shows one structural example of the correction circuit of a present Example. It is a figure which shows the example of a display of an image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 50 Input part 105 Input terminal selection switch 52 Signal conversion part 110 Image selection switch 111,112 Correction circuit 113,115 Color space correction circuit 114,116 Image correction circuit 117 Image composition circuit 118 Format conversion circuit 119 Operation part 120 Control part 54 Memory | storage 60 Projector 303 RGB → XYZ conversion circuit 305 Saturation / hue conversion circuit 306 XYZ → RGB conversion circuit 308 γ correction circuit 310 Brightness / contrast correction circuit

Claims (5)

Corresponding to a plurality of image signals, a plurality of input terminals to which an image by each image signal is input,
A plurality of color space correction circuits for respectively correcting images by the plurality of image signals;
An image selection switch provided between the plurality of input terminals and the plurality of color space correction circuits, for outputting an image of each image signal to each color space correction circuit provided corresponding to each image signal;
When an instruction to select the image signal is input, a control unit that associates an input terminal corresponding to the selected image signal with respect to the image selection switch and a color space correction circuit;
An image output apparatus. A color gamut standard is different for each image signal, and a storage unit that stores a color space profile that is information for converting to a color gamut corresponding to the standard for each image signal,
The control unit reads the color space profile corresponding to the image signal by the input of the instruction from the storage unit and transmits the profile to the color space correction circuit.
The image output apparatus according to claim 1, wherein the color space correction circuit converts the image signal into a standard color gamut of the image signal using the color space profile. A storage unit storing a device profile that is information for conversion to a displayable color gamut of the device itself;
The control unit reads the device profile from the storage unit in response to the input of the instruction, transmits the device profile to the color space correction circuit,
The image output apparatus according to claim 1, wherein the color space correction circuit converts the image signal into a color gamut of the apparatus using the apparatus profile. The image signal is an RGB signal of RGB color system data,
When correction information indicating color correction content is input, the control unit transmits the correction information to the color space correction circuit.
The color space correction circuit converts the RGB signal into an XYZ signal of XYZ color system data, corrects the XYZ signal according to the correction information, and then converts the corrected XYZ signal into the RGB signal. 4. The image output device according to any one of items 1 to 3. An input terminal selection switch to which the plurality of input terminals are connected;
5. The signal conversion unit according to claim 1, further comprising: a signal conversion unit that is connected between the input terminal selection switch and the image selection switch and aligns an image signal input to each input terminal with a digital signal. Image output device.

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