JP2009077007A - Chroma-key composition processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chroma-key composition processing apparatus capable of performing a chroma-key composition processing, even when a chroma-key color is changed due to some sort of reason. <P>SOLUTION: The chroma-key composition processing apparatus is used, when performing the chroma-key composition processing of external videos, such as, television videos in the window of the application software of a personal computer, that is performing the chroma-key composition processing of external video signals and the video signals of the personal computer, and displaying them; and when the chroma-key color is not detected in an area where the chroma-key color should be outputted, the most frequent color is defined as the chroma-key color. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a chroma key composition processing apparatus that displays two video signals after performing chroma key composition processing.

  In recent years, multi-functionalization of personal computers has progressed, and as one of the functions, a personal computer equipped with a function for enabling viewing of a television is sold. In such a personal computer, television images are displayed in a window of TV application software.

  By the way, in the personal computer as described above, it is necessary to synthesize the TV video signal and the video signal of the personal computer. Chroma key synthesis has been conventionally used as a synthesis method. In the chroma key composition in such a case, the personal computer outputs the area in which the television image is to be displayed (combined) as a specific color (chroma key color), and the television image is displayed in this chroma key color area. In this way, the control is performed by the chroma key synthesis circuit.

  Patent Document 1 discloses a technique for performing chroma key composition processing on such a video signal of a personal computer and a television video signal.

JP-A-9-172573

  By the way, as described above, in order to synthesize a television video signal with a video signal of a personal computer, it is assumed that the above-described chroma key color is constant.

  However, for example, if an output image quality adjustment such as gamma correction is performed under the management of the OS so as to correspond to a display in a personal computer, the chroma key color also changes. Further, if the video signal including the chroma key color is deteriorated during transmission, the chroma key color is also changed. In such a case, there arises a problem that the above-described chroma key composition processing cannot be performed.

  Therefore, an object of the present invention is to provide a chroma key composition processing apparatus that can perform chroma key composition processing even when the chroma key color changes due to some cause.

  A first chroma key composition processing apparatus according to the present invention is a chroma key composition processing apparatus for performing chroma key composition processing on a first video signal and a second video signal including a chroma key color in a predetermined area. When the chroma key color is not detected from this area, the most frequent color of the predetermined area is the chroma key color.

  A second chroma key composition processing apparatus of the present invention is a chroma key composition processing apparatus for performing chroma key composition processing on a first video signal and a second video signal including a chroma key color in a predetermined area. Detecting means for detecting whether or not there is a chroma key color, measuring means for measuring the most frequent color of the predetermined area, and when the detecting means does not detect a chroma key color, the measuring means measures And changing means for changing the most frequent color to a chroma key color.

  According to the present invention, it is possible to provide a chroma key composition processing apparatus capable of performing chroma key composition processing even when the chroma key color changes for some reason.

  The best mode for carrying out the present invention will be described below with reference to the drawings. First, the outline of the present embodiment will be described. The chroma key composition processing apparatus of the present embodiment is a chroma key composition process in which an external image such as a television image is displayed in an application software window of an information processing apparatus represented by a personal computer. That is, it is used when displaying an external video signal and a video signal of a personal computer by performing a chroma key composition process, and when a chroma key color is not detected in an area where the chroma key color should be output, The color is a chroma key color. This will be described in detail below.

  FIG. 1 is a block diagram for explaining a chroma key composition processing apparatus according to an embodiment of the present invention. Referring to FIG. 1, a graphic video signal of a personal computer is input to a chroma key color detector 10, a comparator 30, and a chroma key synthesizer 40. On the other hand, an external video signal such as a TV video signal is input to the chroma key synthesizer 40.

  The chroma key color detector 10 is connected to a chroma key color detection result holder 20, the chroma key color detection result holder 20 is connected to a comparator 30, and the comparator 30 is connected to a chroma key combiner 40. Yes.

  Hereinafter, the operation of the chroma key composition processing apparatus of the present embodiment will be described.

  Referring to FIG. 2, the chroma key color detector 10 determines whether or not it is a display period (step S1). If it is not a display period, that is, if it is a vertical blanking period, a chroma key color update flag is not shown. It is detected whether or not the user is standing in the storage area (step S2).

  In step S2, if the chroma key color detector 10 detects that the chroma key color update flag is not set, the chroma key color detector 10 determines whether or not there is a chroma key color in the region where the chroma key color is to be detected. Is detected (step S3). In step S3, the chroma key color to be detected is initially an initial value (in this case, it is necessary to give the initial value to the detection result holder 20), but thereafter, the chroma key color is changed as described later. Chroma key color. Note that the chroma key color to be detected is held in the chroma key color detection result holder 20 and is referred to by the chroma key color detector 10.

  In step S3, if the chroma key color detector 10 does not detect the chroma key color, the chroma key color is changed (step S4). Here, the changed chroma key color is the most frequent color detected as described later in the previous display period, and the chroma key color detection result holder 20 together with the chroma key color to be detected by the chroma key color detector 10 in step S3. Is held in.

  After step S4 and when the detector 10 detects a chroma key color in step S3, the chroma key color detector 10 sets a chroma key color update flag (step S5).

  Next, when the chroma key color detector 10 determines in step S1 that it is not in the display period, that is, the vertical blanking period, the chroma key color detector 10 detects the color existing in the region where the chroma key color is to be detected. In order to obtain the most frequent color, a color histogram (frequency distribution) is measured (step S6). In step S6, the most frequent color detected by the chroma key color detector 10 is held in the chroma key color detection result holder 20 by the chroma key color detector 10. Then, the chroma key color held in the chroma key color detection result holder 20 is used when the chroma key color is changed in step S4 described above. Note that the changed chroma key color is the chroma key color that the chroma key color detector 10 should detect in step S3.

  When the most frequent color is obtained by the chroma key color detector 10 in step S6, the chroma key color detector 10 clears the chroma key color update flag (step S7).

  Next, the chroma key composition process will be described.

  The chroma key color to be detected by the chroma key color detector 10 in the above-described step S3 is input from the chroma key color detection result holding unit 20 to the comparator 30 and the graphic signal of the personal computer and the chroma key color are input. As a result of the comparison, a signal for instructing that an external video signal such as a TV video signal is output from the chroma key synthesizer 40 is output to the chroma key synthesizer 40 in the matching region.

  On the other hand, as a result of the comparison between the graphic video signal of the personal computer and the chroma key color, in the non-matching area, the signal for instructing the graphic video signal of the personal computer to be output from the chroma key synthesizer 40 is the chroma key. It is output to the combiner 40. Then, the chroma key synthesizer 40 performs chroma key composition processing on both video signals and outputs them.

  In the present embodiment described above, in short, a color histogram (frequency distribution) in a region where a chroma key color is to be detected is monitored, and when a change is detected, the chroma key color is adapted to the change. It has changed.

  Therefore, as described above, even if the chroma key color is changed by performing gamma correction or the like, the color after the gamma correction is the chroma key color, so that the chroma key composition display can be performed correctly.

It is a block diagram for demonstrating the structure of embodiment of this invention. It is a flowchart for demonstrating operation | movement of embodiment of this invention.

Explanation of symbols

10 Chroma Key Color Detector 20 Chroma Key Color Detection Result Holder 30 Comparator 40 Chroma Key Synthesizer

Claims (5)

  A chroma key composition processing device that performs chroma key composition processing on a first video signal and a second video signal including a chroma key color in a predetermined area, and when a chroma key color is not detected from the predetermined area, A chroma key composition processing apparatus, wherein the most frequent color of the predetermined area is a chroma key color. A chroma key composition processing device that performs chroma key composition processing on a first image signal and a second image signal including a chroma key color in a predetermined area,
Detecting means for detecting whether or not there is a chroma key color in the predetermined area;
Measuring means for measuring the most frequent color of the predetermined area;
A chroma key composition processing apparatus, comprising: a changing unit that changes the most frequent color measured by the measuring unit to a chroma key color when the detecting unit does not detect a chroma key color.   3. The chroma key composition processing apparatus according to claim 2, wherein the detecting means detects whether or not a chroma key color exists in the predetermined area during a vertical blanking period of the second video.   4. The chroma key composition processing apparatus according to claim 2, wherein the changing unit sets the most frequent color measured by the measuring unit to a chroma key color during a vertical blanking period of the second video. The chroma key composition processing apparatus, wherein the chroma key color changed in the vertical blanking period of the second video by the changing means is the most frequent color measured by the measuring means in the immediately preceding display period.

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