JPS6448987U

JPS6448987U -

Info

Publication number: JPS6448987U
Application number: JP14461787U
Authority: JP
Priority date: 1987-09-21
Filing date: 1987-09-21
Publication date: 1989-03-27

Description

[Brief explanation of drawings]

第１図はこの考案の一実施例によるＮＴＳＣ方
式画像相関対応輝度信号色信号分離フイルタを示
す概略ブロツク図、第２図はその画像相関判定回
路の一実施例を示すブロツク図、第３図及び第４
図はそれぞれ上記画像相関判定回路の第１、第２
の実施例を示す回路図、第５図は従来の輝度信号
色信号分離フイルタの一例を示す概略ブロツク図
、第６図はＮＴＳＣ方式の複合カラーテレビジヨ
ン信号を色副搬送波の４倍で同期標本化した信号
系列の画面上での配列を示す説明図である。図において、１……入力端子、２，３……出力
端子、４……Ａ／Ｄ変換器、５ａ〜５ｊ……遅延
回路、６ａ〜６ｋ……デイジタルフイルタ、７…
…画像相関判定回路、８……スイツチ回路、９ａ
〜９ｅ……減算回路、１０ａ〜１０ｅ……絶対値
回路、１１ａ〜１１ｅ……比較回路、１２ａ〜１
２ｅ……定数発生回路、１３ａ……垂直相関検出
回路、１３ｂ……水平相関検出回路、１４……判
定回路、１５……ＯＲ回路、１６ａ，１６ｂ……
ＮＯＴ回路、１７ａ〜１７ｃ……ＡＮＤ回路、１
８……排他的ＯＲ回路。なお、図中、同一符号は
同一、又は相当部分を示す。 FIG. 1 is a schematic block diagram showing an NTSC system image correlation compatible luminance signal/chrominance signal separation filter according to an embodiment of the invention, FIG. 2 is a block diagram showing an embodiment of the image correlation determination circuit, and FIGS. Fourth
The figure shows the first and second circuits of the image correlation determination circuit, respectively.
FIG. 5 is a schematic block diagram showing an example of a conventional luminance signal/chrominance signal separation filter. FIG. 6 is a synchronous sampling of an NTSC system composite color television signal using four times the color subcarrier. FIG. 2 is an explanatory diagram showing an arrangement of converted signal sequences on a screen. In the figure, 1...input terminal, 2, 3...output terminal, 4...A/D converter, 5a-5j...delay circuit, 6a-6k...digital filter, 7...
...Image correlation determination circuit, 8...Switch circuit, 9a
~9e...Subtraction circuit, 10a-10e...Absolute value circuit, 11a-11e...Comparison circuit, 12a-1
2e... Constant generation circuit, 13a... Vertical correlation detection circuit, 13b... Horizontal correlation detection circuit, 14... Judgment circuit, 15... OR circuit, 16a, 16b...
NOT circuit, 17a-17c...AND circuit, 1
8...Exclusive OR circuit. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims

[Claims for Utility Model Registration] (1) A composite video signal sampled at a predetermined frequency synchronized with the horizontal scanning frequency so that each sample point is arranged in a grid on the screen is input, and from this composite video signal In a luminance signal/chrominance signal separation filter that digitally separates luminance signal components and chrominance signal components, the composite video signal is delayed and the luminance signal and chrominance signal are to be separated from each other at a sample point of interest and on the screen. a delay means for simultaneously obtaining sample values of a plurality of reference sample points arranged in a straight line in the vertical direction with the sample point of interest; a vertical color signal extraction filter that extracts and outputs a frequency component corresponding to a component of a color subcarrier in the horizontal direction; a horizontal direction color signal extraction filter that extracts and outputs a horizontal color signal extraction filter; a horizontal/vertical color signal extraction filter that outputs a horizontal/vertical color signal extraction filter, which inputs the sample values of the sample point of interest and a predetermined reference sample point, and that the frequency component at the sample point of interest is a low frequency component in the vertical direction, and horizontal high-frequency luminance signal energy detection means for extracting a frequency component corresponding to one-half of the color subcarrier frequency in the horizontal direction and determining the absolute value thereof to detect horizontal high-frequency luminance signal energy; The sample values of the sample point of interest and a predetermined reference sample point are input, and the frequency component at the sample point of interest is a low frequency component in the horizontal direction, and is half the color subcarrier frequency in the vertical direction. vertical high frequency luminance signal energy detection means for extracting a corresponding frequency component and determining its absolute value to detect vertical high frequency luminance signal energy; The vertical high-frequency luminance signal energy is smaller than the first set value, and the vertical high-frequency luminance signal energy is subtracted from the horizontal high-frequency luminance signal energy. The magnitude of the value is compared with a second setting value given from the outside, and from the horizontal high-frequency luminance signal,
vertical correlation detection means for determining that there is a correlation in the vertical direction when the value obtained by subtracting the vertical high-frequency luminance signal energy is greater than the second set value; the horizontal high-frequency luminance signal energy is smaller than the third preset value, and the horizontal high-frequency luminance signal energy is subtracted from the vertical high-frequency luminance signal energy. The value obtained by subtracting the horizontal high-frequency luminance signal energy from the vertical high-frequency luminance signal energy is greater than the fourth preset value. horizontal correlation detection means that determines that there is a correlation in the horizontal direction; and a frequency component corresponding to a color subcarrier component, and detecting diagonally upward-rightward decorrelated energy by determining its absolute value; and The sample value of the reference sample point is input, and the DC component in the diagonally downward downward direction and the frequency component corresponding to the color subcarrier component are excluded from the frequency components at the sample point of interest, and their absolute values are calculated. a diagonally right-down direction uncorrelated energy detection means for detecting diagonally right-down direction uncorrelated energy; energy comparison detection means for both diagonal directions that determines whether the energy is larger or smaller than a given fifth set value; and the determination result of the vertical correlation detection means, the determination result of the horizontal correlation detection means, and the energy comparison detection for both diagonal directions. The determination result of the means is input, and according to the magnitude of the determination result of the energy comparison detection means in both diagonal directions and the determination result of the presence or absence of correlation in the horizontal and vertical directions,
a determining means for transmitting a control signal for selecting the output of the horizontal color signal extraction filter, the vertical color signal extraction filter, or the horizontal/vertical color signal extraction filter; An image correlation compatible luminance signal/chrominance signal comprising: a switch circuit that outputs a color signal component according to the image correlation; and a subtraction circuit that subtracts the output of the switch circuit from the composite video signal to output a luminance signal component. Separation filter. (2) The determination means outputs a horizontal color signal extraction filter when the result of the comparison detection of the energy in both diagonal directions by the energy comparison detection means in both diagonal directions is smaller than the fifth set value and there is a correlation in the horizontal direction. If the comparison detection result of both diagonal energies is smaller than the fifth set value and there is no correlation in the horizontal direction but correlation in the vertical direction, vertical color signal extraction is performed. Sending a control signal for selecting a filter output, and determining that the energy comparison detection result in both diagonal directions is smaller than the fifth set value and has no correlation in either the horizontal direction or the vertical direction, or the energy in both diagonal directions is Claim 1 of the utility model registration claim, characterized in that, when the comparative detection result is larger than the fifth set value, a control signal is sent to select the output of the horizontal/vertical color signal extraction filter. The image correlation compatible luminance signal chrominance signal separation filter described above. (3) The determination means determines when the result of the comparison detection of the energy in both diagonal directions by the energy comparison detection means in both diagonal directions is smaller than the fifth set value, and there is a correlation in the horizontal direction but no correlation in the vertical direction. ,
Sending a control signal for selecting a horizontal color signal extraction filter output, and determining that the two diagonal energy comparison detection results are smaller than the fifth set value, have no correlation in the horizontal direction, and have no correlation in the vertical direction. If so, send a control signal for selecting a vertical color signal extraction filter output, and determine that the energy comparison detection result in both diagonal directions is smaller than the fifth set value and that there is a correlation in both the horizontal and vertical directions. , or if there is no correlation, or if the energy comparison detection result in both diagonal directions is larger than the fifth set value, a control signal for selecting the output of the horizontal/vertical color signal extraction filter is sent out. An image correlation compatible luminance signal/chrominance signal separation filter according to claim 1, which is characterized by the utility model registration.