JPH02180487A - Color motion detection circuit - Google Patents

Abstract

PURPOSE:To easily and exactly detect the motion of a color without being interfered by a luminance signal only with one frame by adding a circuit to detect the difference of luminance in an oblique direction by using two line memories. CONSTITUTION:Not only a chrominance signal but also the luminance signal around 3.58MHz are taken out from comb-line filters 13 and 14. Out of this luminance signal, the pattern of the luminance signal in lateral or longitudinal direction is removed by the comb-line filters 13 and 14. However, concerning the pattern in the oblique direction, the luminance signal is reversely emphasized and appears as the chrominance signal. In order to detect the generation of this signal, a line memory 18 is added to delay a line memory 131 of the comb- line filter 13 further for one more line. By passing both edges of these two lines through a subtracter 18, the differential of the luminance signal in the oblique direction is detected. Thus, it can be prohibited to generate the motion signal of the color in the pattern of a still picture in the oblique direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to digital TV receivers, digital VTRs, etc., and particularly to a motion detection circuit for a circuit that performs three-dimensional signal processing between frames or between fields.

[Conventional technology]

There is a system called high-quality TV (IOTV) that utilizes three-dimensional processing between frames and fields. This takes advantage of the fact that the color phase of the NTSC signal is inverted between frames, and adds the signals between frames.
By subtracting, a complete luminance-chrominance signal (hereinafter abbreviated as YC separation) is performed, and an extremely fine image is provided.

However, in moving signals, that is, moving images, a shift occurs in the signals between frames, making it impossible to perform three-dimensional processing. Therefore, for signals with movement, it is switched to in-field signal processing. A motion detection circuit performs this switching.

Conventionally, in this type of motion detection circuit, the color phase of the NTSC signal is inverted in the next first frame and becomes the same phase in the next second frame, and the difference between the two frames is taken to detect the brightness and color movement. signal can be detected. However, using two frames of memory is expensive in practice, and methods of detecting these motion signals using one frame have been studied. Although the movement of the 1Ⅲ degree signal can be easily detected by taking the difference between the signals between frames, it has been extremely difficult to detect the color movement signal.

FIG. 4 is a block diagram of the conventional color motion detection circuit described above.

The digitized input signal 401 is transmitted to the frame memory 40
2 causes a delay of one frame. Color signals are detected from the input signal 401 and a signal delayed by one frame by comb-shaped filters 403 and 404, each using a line memory.

This is converted into an absolute value by absolute value circuits 405 and 406, and a difference detection circuit 407 that detects the difference between these signals generates a motion signal 408 between color frames regardless of the luminance signal.
can be detected.

(T!!! Problem to be Solved by the Invention) The conventional color motion signal detection circuit described above can detect color motion in a signal with no change in the luminance signal, but If it has a component close to the carrier wave 3°579545HIIZ, this will be input as a color signal, which may cause a color motion signal to be generated by mistake even in a still image, especially for luminance signals in diagonal directions. If there is a line, the comb-shaped filter between the lines will process it as a color signal, generating beats with the original color signal, and the absolute values of these will differ between frames. Therefore, the difference detection circuit treats it as if a color movement has occurred, and the YC separation between frames that has been processed in 3D is also treated as 2 because a movement has occurred in this part of the picture.
There is a drawback that YC separation occurs within the dimensional field.

(Means for Solving the Problems) The color motion detection circuit of the present invention includes a frame memory that delays a digitized input video signal by one frame, and a first comb-shaped filter that extracts color components of the input video signal. , a second comb-shaped filter that extracts the color components of the input signal output from the frame memory, and first and second absolute value circuits that detect the absolute values of the output signals of the first and second comb-shaped filters, respectively. a fin memory that delays an input video signal by two lines; a subtraction circuit that takes the difference between signals at both ends of this line memory; a third absolute value circuit that detects the absolute value of this output signal; and a difference detection circuit that detects the difference between the outputs of the second absolute value circuit and controls not to output the difference when a signal is input from the third absolute value circuit.

[Effect]

By adding a circuit that detects differences in brightness in diagonal directions using a 2-line memory, color movement signals can be detected extremely easily and reliably in just one frame without being interfered with by brightness signals. can do.

[Embodiment P14] Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a color motion detection circuit according to the present invention.

The frame memory 12 delays the input signal 11, which is a video signal digitized by A/D conversion, by one frame.

The comb filter 13 (14) is the line memory 131
(141), a subtractor 132 (142), and a bandpass filter 133 (143), each of which extracts 3, 58HH7 components, which are the color subcarriers of the color signal, from the signal before extending one frame and the delayed signal. It is something that allows invasion to pass through. The absolute value circuit 1
5.16, it is converted to direct current, and the difference detection circuit 17
Accordingly, a detection output 21 which is the difference between the respective signals can be obtained.

Not only color signals but also 3
．． Luminance signals around 58 H1lz are also extracted. Of these, the horizontal and vertical brightness signals of the picture are removed by the comb-shaped filters 13 and 14, but for the diagonal picture, the luminance signal is emphasized and appears as a color signal. In order to detect the occurrence of this signal, a line memory 18 is added which delays the line memory 131 of the comb filter 13 by one more line. By passing both ends of these two lines through a subtracter 19, the difference between the luminance signals in the diagonal direction is detected.

This takes advantage of the fact that the hue of the color signal is inverted line by line, and two lines have the same phase. At this time, if the luminance signals between the two lines are different, this can be reliably detected. The output of this subtracter 19 is converted to the absolute value circuit 2.
0 to convert it into a direct current, and input it to the difference detection circuit 17. When the difference detection circuit 17 receives the signal from the absolute value circuit 20, it performs control in a direction in which the detection output 21 is not output.

As a result, it is possible to prohibit the generation of color motion signals in the diagonal still image pattern.

Note that a low-pass filter may be inserted after each absolute value circuit 15, 16, and 20 in order to remove fine edges. Further, the present diagonal direction detection circuit may be attached not only to the input signal side but also to the comb-shaped noilter 14 after the frame memory 12.

FIG. 2 is a block diagram of a second embodiment of the color motion detection circuit of the present invention.

This embodiment has a configuration similar to that of the first embodiment, and the input signal 2
01, frame memory 202, comb filter 203 (
(line memory 231, subtractor 232, bandpass filter 233), comb filter 204, (line memory 241, subtracter 242, bandpass filter 243),
Absolute value circuit 205.206.211, line memory 20
8, subtracter 209, adder 210. Difference detection circuit 207
, a detection output 212.

In this embodiment, since the difference between the luminance signals in the diagonal direction is detected for each line, it is possible to detect a signal that is shifted by one line.

FIG. 3 shows a combination of the color motion detection circuit of the present invention and the Oilff motion detection circuit, which makes it possible to detect all motion. Color motion signal detection circuit 302
is the color motion detection circuit of the present invention, and the frame memory 30
3. Comb-shaped filter 304, 305, 2. Consists of an inter-line difference detection circuit 308, absolute value circuits 306, 307, 309, and a difference detection circuit 310, and color motion signals can be detected here. By passing this signal through an absolute value circuit 311 and a low-pass filter 312, a color movement signal output 318 can be extracted. Difference detection circuit 313
is a circuit that detects the difference, which is the movement of the E11 signal, by taking the difference between the input signal 301 and the output of the frame memory 303.The low-pass filter 314 removes the color signal component, and the absolute value circuit 315 removes the brightness Kl component. ] and take out the signal 317. Both motion outputs 317 and 318 are added by an adder circuit 316 to form a complete motion signal (detection signal 319).

(Effects of the Invention) As explained above, the present invention extracts color signals from signals at both ends of a frame memory using a comb-shaped filter using a line memory, passes this signal through an absolute value circuit, and calculates the difference between each. Add another line of memory to the detection circuit, take the difference between the signals at both ends of these two lines of memory,
By passing the diagonal component of the luminance signal through an absolute value circuit, the diagonal component of the luminance signal is detected, and when this signal is detected, the output of the difference detection circuit is not output. This has the effect of allowing you to extract the detected object as a still image.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a first embodiment of the color movement detection circuit of the present invention, FIG. 2 is a block diagram of a second embodiment of the color movement detection circuit of the present invention, and FIG. 3 is a block diagram of a second embodiment of the color movement detection circuit of the present invention. A block diagram of a third embodiment of the color motion detection circuit, and FIG. 4 is a block diagram of a conventional example. 11.201.301...input signal, 12.202.
303...Frame memory, 13.14,203,2
04,304.305...Comb-shaped filter, 15.16,20,205,206,211°306.
307,309,311.315...Absolute value circuit, 17.207,310.313...Difference detection circuit, 2
1.212,319...detection output, 131,141.
18,231,208.241...Line memory, 132.142.19,209,232.242...
Subtractor, 133.143,233,243...Band pass filter, 210...Adder, 302...Color movement detection circuit, 312.314...Low pass filter, 316...
Addition circuit, 308... Two-line difference detection circuit, 317... Luminance movement signal output, 318... Color movement signal output.

Claims (1)

[Claims] 1. A frame memory that delays the digitized input video signal by one frame, a first comb-shaped filter that extracts the color components of the input video signal, and a second comb-shaped filter that extracts the color components of the input signal output from the frame memory. a comb-shaped filter, first and second absolute value circuits that detect the absolute values of the output signals of the first and second comb-shaped filters, respectively, a line memory that delays the input video signal by two lines, and a line memory that delays the input video signal by two lines; a subtraction circuit that takes the difference between signals at both ends of the memory, a third absolute value circuit that detects the absolute value of this output signal, and a first
, a difference detection circuit that detects a difference between the outputs of the second absolute value circuit and controls the difference not to be output when a signal is input from the third absolute value circuit.