KR19980040687A - Chromatic Keying Device Using Color Window - Google Patents

Abstract

A chromaticity keying device using a color window is disclosed. Color inputting a first color difference signal and a second color difference signal having an arbitrary digital video format and outputting a chromaticity signal that can be displayed on one screen according to one chromaticity state. A first interpolation means for interpolating to a 4: 4: 4 format defined in the protocol, a second interpolation means for interpolating a second color difference signal to a 4: 4: 4 format defined in the International Communication Protocol, and Selecting the first and second color difference signals in response to the first selection signal, and outputting the selected signal to the first multiplexer, the output of the first interpolation means and the output of the second interpolation means in response to the second selection signal. A second multiplexer for outputting the selected signal as a chroma signal and a signal output from the first multiplexer are mapped to a color window, the mapped background color is detected and output as a second selection signal, and the selection is performed. And chromaticity keying control means for generating a first selection signal corresponding to a specific color to be used, wherein the value of use is increased by the chromaticity keying function in processing a signal having inputs of two channels, and the characteristics of the digital video data are characterized. It is effective to simply implement various functions using.

Description

Chroma Keying Device with Color Window

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of chromatic signal processing in digital video signal processing, and more particularly, to a chromaticity keying apparatus using a color window for performing chromaticity keying using a color window.

As digital video signal processing has become more common, various functions have been required. Luma Keying and Chroma Keying are among the functions that are processed prior to video encoding to meet such needs.

The keying function is a function that allows two screens to overlap. First, luminance keying is an overlapping method using the characteristics of the luminance component, and chromaticity keying is an overlapping method using the chrominance components.

Hereinafter, a configuration and operation of a conventional chromaticity keying apparatus will be described with reference to the accompanying drawings.

1 is a block diagram of a conventional chroma keying device, wherein first and second key generators 10 and 16, a non-additive mix 12, a foreground suppersor 14 , Mixers 18, 22, and 24 and adder 20.

The apparatus shown in FIG. 1 processes the foreground and background images respectively before composing the foreground and background images. Rather than choosing between the foreground and the background, each processed is synthesized. The power key Kfg and background key Kbg signals output from the first key generation unit 10 and the second key generation unit 12, respectively, have a range of 0 to 1. A garbage matte key signal input via input terminal IN2 causes the mixer to output the foreground source in one of two ways. Here, mat is a word derived from the film industry.

One way is to decrease Kbg proportionally as Kfg increases. This has the advantage of minimizing the black edges around the inserted foreground. The second method is to make the background black at all non-zero values of the matte key and insert the foreground into the hole in the background. This is a problem that requires a cleaning function to remove the noise near the black level affecting the background screen due to the addition process.

The garbage matte signal input through the input terminal IN2 is added with the foreground key signal Kfg using the non-addition mixer 12. The non-additive mixer 12 causes a brighter of the two images to generate a key signal on a pixel basis. Matting is ideal for any source that generates its own key signal, but not for real circuits.

An object of the present invention is to provide a chromaticity keying apparatus using a color window that determines whether two input color difference components exist in a color range and superimposes two screens on one screen.

1 is a block diagram of a conventional chroma keying device.

2 is a block diagram of a chroma keying device according to the present invention.

3 is a view for explaining the concept of the chroma keying device according to the present invention shown in FIG.

In order to achieve the above object, using the color window according to the present invention to input a first color difference signal and a second color difference signal having an arbitrary digital video format and output a chromaticity signal that can be displayed on one screen according to one chromaticity state The chroma keying device includes: first interpolation means for inputting the first color difference signal to interpolate to a 4: 4: 4 format defined by an international communication protocol, and 4 specified by the international communication protocol by inputting the second color difference signal. Second interpolation means for interpolating to a 4: 4 format, a first multiplexer for selecting the first and second color difference signals input in response to a first selection signal, and outputting the selected signal; A second multiplexer and the first mulch configured to select an output of the first interpolation means and an output of the second interpolation means in response to a second selection signal, and output the selected signal as the chroma signal; And a chromaticity keying control means for mapping the signal output from the flexor to the color window, detecting the mapped background color and outputting it as the second selection signal, and generating the first selection signal corresponding to the specific color to be selected. desirable.

Hereinafter, the configuration and operation of a chromaticity keying apparatus using a color window according to the present invention will be described with reference to the accompanying drawings.

2 is a block diagram of a chroma keying apparatus according to the present invention, wherein the first and second interpolators 40 and 42, the first and second multiplexers (MUX1 and MUX2) 44 and 46, and the chroma keying controller are shown in FIG. It consists of 48.

The digital video component signal is generally composed of a luminance signal (Y) and color difference signals (Cr and Cb) as defined by the International Communication Protocol (CCIR), and the signal processing is performed independently by luminance signal processing and chromatic signal processing, respectively. many.

The first interpolator 40 illustrated in FIG. 2 inputs a first color difference signal Cr having an arbitrary digital format through channel 1 CH1 to perform CCIR 4: 4: 4 formatting. If the input signal is already in 4: 4: 4 format, the first interpolator 40 does not perform interpolation on the first color difference signal and outputs it as it is.

Similarly, the second interpolator 42 inputs a second color difference signal Cb having an arbitrary digital format through channel 2 CH2 to perform CCIR 4: 4: 4 formatting. If the input signal is already in 4: 4: 4 format, the second interpolator 42 does not interpolate the second color difference signal and outputs it as it is.

Meanwhile, the first MUX 44 inputs first and second color difference signals input through the channel 1 and the channel 2, respectively, and selectively outputs the chroma keying controller 48 in response to the first selection signal S1. ) Here, the first selection signal is a control signal generated corresponding to the specific color to be selected.

The chroma keying control unit 48 inputs a signal outputting a signal from the first MUX 44 and receives a second selection signal S2 for selecting the foreground or the background according to the color window input through the input terminal IN. Output to (46).

3 is a view for explaining the concept of the chroma keying device according to the present invention shown in FIG. 2, wherein the vertical axis represents the second color difference signal Cb and the horizontal axis represents the first color difference signal Cr.

Points A and B shown in FIG. 3 are coordinate points for detecting the color data range of the input to be keyed and are variable. That is, the chroma keying control unit 48 operates to map the color signal input from the first MUX 44 to a predetermined color window and detect the mapped background color.

As a result, the chromaticity keying apparatus according to the present invention selects only the color difference component from the two input digital video component signals and determines the output according to whether the input color difference component lies in a predetermined color range. In other words, the two inputs are divided into a foreground and a background, and display on the circle screen according to the state of one chromaticity.

As described above, the chroma keying apparatus using the window according to the present invention detects a region of the mapped color and performs chroma keying, so that the value of use by the chroma keying function in the signal processing with input of two channels is reduced. Increasingly, various functions can be easily implemented by using characteristics of digital video data.

Claims (1)

A chroma keying device using a color window for inputting a first color difference signal and a second color difference signal having an arbitrary digital video format and outputting a chromaticity signal that can be displayed on one screen according to one chromaticity state. First interpolation means for inputting the first color difference signal to interpolate to a 4: 4: 4 format defined by an international communication protocol; Second interpolation means for inputting said second color difference signal to interpolate to said 4: 4: 4 format defined by said international communication protocol; A first multiplexer which selects the input first and second color difference signals in response to a first selection signal and outputs the selected signal; A second multiplexer for selecting the output of the first interpolation means and the output of the second interpolation means in response to a second selection signal, and outputting the selected signal as the chroma signal; And And chromaticity keying control means for mapping the signal output from the first multiplexer to a color window, detecting the mapped background color and outputting the mapped background color as the second selection signal, and generating the first selection signal corresponding to a specific color to be selected. Chromaticity keying device using a window, characterized in that.