JPH011390A - Color-luminance separation circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color-luminance separation circuit that separates a composite signal of a color television into a luminance signal and a color signal.

[Prior Art] Conventionally, as a YC separation method for separating a color television composite signal into a luminance signal Y and a color signal C, a fourth method has been proposed.
As shown in the figure, a trap filter 101 or a low pass filter (LPF) and a band pass filter (BF
P) 102, as shown in FIG. 5, a comb filter that uses a delay line (1) IDL) 103 for one horizontal scanning period and adders 104 and 105, or as shown in FIG. As shown, there is a method in which YC is separated from interfield or interframe signals which are added by adders 104 and 105 using memory 106.

[Problems to be Solved by the Invention] However, the conventional YC separation method using the trap 101 and bandpass filter 102 shown in FIG. 4 generates interference waves called cross color and dot crawl, and also The resolution of the signal also decreases and deteriorates.

In addition, another example of the daily day line 103 shown in FIG.
, the YC separation method using a comb filter using adders 104 and 105, etc. takes the average between two vertically adjacent lines (scanning lines), which degrades the vertical resolution and further increases the If there is no correlation between two signals, a false signal is generated. Furthermore, in the method of YC separation between fields (or frames) using the field (or frame) memory 106 according to another example shown in FIG. 6, a false signal is generated for a moving image, and the circuit configuration becomes complicated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a color/luminance separation circuit that eliminates the drawbacks of the conventional example described above and is capable of separating a luminance signal and a color signal with good quality.

[Means for solving the problem] In order to achieve such an object, the present invention creates a composite signal "y+c" and a composite signal "Y-" in which only the phase of the subcarrier of the color signal C is inverted by 180 degrees. C'', respectively, and color and luminance separation is performed using these two systems of composite signals.

That is, in a color-luminance separation circuit that separates a composite signal consisting of a luminance signal and a subcarrier chrominance signal of a color television video signal into color and luminance, a signal obtained by inverting the phase of the luminance signal and the subcarrier chrominance signal is used. The present invention is characterized by comprising means for forming a sub-composite signal, addition means for adding the composite signal and the sub-composite signal, and subtraction means for subtracting the sub-composite signal from the composite signal.

[Function] According to the present invention, calculation can be performed using two completely correlated composite signals Y+C and Y-C, and the complete original luminance signal Y and color signal C can be separated and extracted. can.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

In FIG. 1, 100 and 200 are video equipment. 1 is a composite signal (Y+C) forming circuit according to the color television standard system of the video equipment 10G, 2 is a composite (sub) signal (y-c) forming circuit in which the phase of the chroma signal C of the video equipment 100 is inverted, and 3 is a Composite signal (Y+C) input terminal of video equipment 200, 4
is the sub signal (y-c) input terminal of the video equipment 200, 5
and 6 are adders.

The adder 5 adds the composite signal (Y+C) and the sub-signal (y-c) to generate the luminance signal Y.
is obtained, and adder 6 generates a composite signal (Y+[;)
A chroma signal C is obtained by taking the difference between

FIGS. 2A, 2B, 2C, and 2D are waveform diagrams showing the operation of each component shown in FIG. 1.

FIG. 2(A) shows the output waveform of the composite signal (Y+C), and FIG. 2(B) shows the output waveform of the sub-signal (Y-C). FIG. 2(C) shows the output waveform of the luminance signal Y obtained by adding the composite signal (y+c) and the sub-signal (Y-C) by the adder 5. FIG. 2(D) shows the output waveform of the color signal C obtained from the adder 5 as the difference between the composite signal (y-c) and the sub-signal (y-c).

FIG. 3 is a block diagram showing the configuration of another embodiment of the present invention.

In FIG. 3, the same parts as in FIG. 1 are given the same reference numerals and their explanations will be omitted. 7 is 1) IDL.

In the embodiment shown in FIG. 3, in order to maintain compatibility with conventional equipment, 1) signals from the IDL7 (or frame memory) and sub-! '3- (
Y-C)
It is equipped with a WI.

As can be seen from the above embodiments, it is not only applicable to composite signals according to the color television standard system, but also
NTSC system in the US, and PA in Europe
It can also be applied to L and SECAM systems.

[Effects of the Invention] As is clear from the above, according to the present invention, the luminance signal Y and the color signal C are often separated and processed separately in video equipment. This allows very easy and good signal processing. In addition, compatibility with conventional equipment can be easily achieved, and the number of parts required to implement the present invention is small, which is advantageous from a cost perspective.
High image quality can be easily achieved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention, FIGS. 2(A) to (D) are waveform diagrams showing the operation of each part of the configuration shown in FIG. 1, and FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention. FIG. 4 is a block diagram showing the 11 components of the conventional example, FIG. 5 is a block diagram showing the configuration of another conventional example, and FIG. 6 is another conventional example. FIG. 2 is a block diagram showing the configuration of an example. l...Composite signal forming circuit, 2...Sub signal forming circuit, 3...Composite signal input terminal, 4...Sub signal input terminal, 5.6, 104, 105...Adder, 7 .103...
・1) IDL. 100.200...Video equipment, 101...Trap filter, 102...Band pass filter (BPF), 106.
...Frame memory. Fig. 1 A signal diagram for Eli in the operation theory of each dark machine Fig. 2 A block diagram showing the configuration of I1 of the present invention of the present invention Fig. 3 A conventional example Figure 77 is a block diagram showing the configuration of other conventional I1s.

Claims (1)

[Claims] Color-luminance separation of a composite signal consisting of a luminance signal and a subcarrier color signal of a color television video signal.
In the luminance separation circuit, means for forming a subcomposite signal consisting of the luminance signal and a signal obtained by inverting the phase of the subcarrier chrominance signal; addition means for adding the composite signal and the subcomposite signal; A color-luminance separation circuit comprising: subtraction means for subtracting the sub-composite signal from the composite signal.