JPH05137160A - Field converting circuit - Google Patents

Abstract

PURPOSE:To eliminate a centroid movement, and also, to eliminate deterioration of oblique resolution by detecting a separated luminance signal, executing a still picture processing, in the case of a still picture, and varying a mixing ratio in accordance with a motion signal and synthesizing it, in the case of a motion picture. CONSTITUTION:A luminance signal separated by a motion adaptive Y/C separating circuit is inputted to a motion detecting circuit 50. In the case it is decided to be a still picture by the circuit 50, a still image processing is executed by a luminance signal Y adaptive scanning line converting circuit 70, and in the case it is decided to be an animated picture, an animated picture processing is executed by the luminance signal Y adaptive scanning line converting circuit 70. In such a state, based on a control signal from a signal control circuit 100, from a first - a third taps of a delaying circuit 20 with a tap, signals B2V-C5V are outputted to an inputted video signal C1V. Also, a soft switch circuit 40 is set so as to become a motion mode by the circuit 50. As a result, outputs of the still picture and the animated picture from the converting circuit 70 are synthesized by varying a mixing ratio in accordance with the motion signal from the circuit 50. In such a way, a centroid movement is eliminated, and also, deterioration of oblique resolution can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to field conversion for producing field data of a new field number from field data of an arbitrary field number during variable speed reproduction of a magnetic recording / reproducing apparatus (hereinafter abbreviated as VTR). Regarding the circuit.

[0002]

2. Description of the Related Art When reproducing a video signal recorded on a VTR or the like, the screen is appropriately thinned out for adjustment of the reproduction time, or for slow reproduction, fast reproduction, still image reproduction, etc. which produce a special effect. , The same screen may be displayed repeatedly. At this time, the interlace condition of the video signal and the continuity condition of the color subcarrier should be satisfied, that is, NT.
In case of SC TV signal, 4 of 4 field sequence
In order to maintain the continuity of one field number, it is necessary to create a video signal having a field number different from the reproduced video signal. In order to realize this, it is often practiced to reduce the vertical resolution of the image during special reproduction by using an interpolation filter technique. Television Society Technical Report, Vo
l. 14, No. 47, pp. 13 to 18, "One Method of Playback Video Process in Composite Digital VTR", shows a processing technique when the above processing is performed in a digital VTR.

[0003]

As illustrated in the above-mentioned document, in these methods, the center of gravity of the pattern moves due to the field conversion. The movement of the center of gravity of the design gives a sense of visual instability and significantly deteriorates the image quality. Also, as described in the above document, if the band of the comb filter that separates the luminance signal and the carrier color signal is narrow, the carrier color signal remains in the luminance signal, and the phase of the carrier color signal accompanying field conversion is changed. Due to the inversion process, the band of the carrier color signal is changed to cause color flicker, which significantly deteriorates the image quality. If the band of the comb filter is widened in order to prevent this, the diagonal resolution of the luminance signal deteriorates, resulting in a so-called blurred picture. As described above, the prevention of the color flicker and the reduction of the deterioration of the diagonal resolution of the luminance signal are different conditions, and at the same time, both the conditions cannot be satisfied, which causes a problem that the image quality is deteriorated.

An object of the present invention is to eliminate the shift of the center of gravity associated with signal processing during variable speed reproduction described above, to eliminate color flicker,
Moreover, it is intended to improve the image quality during variable speed reproduction by eliminating the deterioration of the diagonal resolution of the luminance signal and the deterioration of the resolution of the color signal.

[0005]

In order to achieve the above object, the present invention utilizes the correlation of signals between frames in the still image portion, and utilizes the correlation of signals between lines in the moving image portion. Signal Y and carrier color signal C are separated (Y / C separation)
To do. Then, for each of the luminance signal and the carrier color signal,
In the still image portion, scanning line conversion is performed using signals between fields that interlace with each other. In the video part,
Scan line conversion is performed using a signal of a line to be converted into a scan line, a signal of a line adjacent to the line, and a signal of a different field number having an interlacing relationship with them. When the levels of the signals of different field numbers, which are in the interlaced relationship, fall between the signal levels of the lines adjacent to each other, scanning line conversion is performed using the signals of the fields. If not, scanning line conversion is performed using a signal between lines. The carrier color signal is adjusted in phase so as to maintain the continuity of the color subcarrier, and then added to the processed luminance signal and output.

[0006]

The reproduced composite video signal is separated into the luminance signal Y and the carrier color signal C by the frame Y / C separation circuit and the line Y / C separation circuit. Further, the composite video signal delayed by one field is also separated into a luminance signal and a chrominance signal by the frame Y / C separation circuit. Since the interlaced data is input in the scanning line conversion filter using the signal between fields in the still image portion, scanning line conversion can be performed without rattling of the luminance vertical edge portion. In the moving image part, when the signal levels of different fields fall between the signal levels of the adjacent lines, the line-to-field signals are used for scanning line conversion.
Scan line conversion can be performed without rattling of vertical edges.
Further, since the signal level of the scanning line after conversion becomes a value between adjacent lines, it does not become an abnormal signal and an afterimage does not occur. Further, when the signal levels of different fields do not fall within the signal levels of adjacent lines, scan line conversion is performed using only the signal between lines, so that an afterimage does not occur. Further, the separated carrier color signal C can maintain the continuity of the color subcarrier by controlling the presence / absence of phase inversion. By adding the luminance signal and the chrominance signal which have been subjected to these signal processing, it is possible to eliminate the afterimage and the rattling at the luminance edge, and it is possible to realize the field conversion maintaining the continuity of the color subcarrier. further,
In the frame Y / C separation circuit, since the comb filter can be configured over the entire band of the video signal without deterioration of resolution, there is no deterioration of resolution of the color signal, and the residual carrier color signal in the luminance signal can be eliminated. The color flicker can be eliminated.

[0007]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a diagram for explaining the operation of FIG. 1, shows the positions of the scanning lines of the signals of the respective parts, and has a time axis in the horizontal direction, and sequentially becomes a new field. The symbols A, B, C ... In FIG. 2 indicate the positions of the scanning lines, and the subscripts indicate the field numbers. When a composite video signal, a luminance signal, a carrier color signal, etc. are shown for the signal positions, A1, B2, ..., Symbols V, Y, C, etc. are added after each coordinate. The arrow indicates the phase of the color subcarrier in the case of an NTSC signal.

A description will be given below with reference to the drawings. In FIG. 1, 1 is an input terminal of a composite video signal, 2 is an output terminal of a composite video signal after field conversion, 3 is an input terminal of a signal indicating a field number of a reproduced video signal, and 4 is an output video after signal processing. A signal input terminal indicating the field number of the signal, an input terminal 5 for a mode signal indicating reverse reproduction,
Reference numeral 11 denotes a line C comb filter that outputs a carrier color signal,
Reference numeral 20 is a delay circuit with a tap for delaying a signal in a field unit, 30 to 32 are subtraction and averaging circuits that reduce the signal level to ½ after subtraction, 33 and 34 are subtraction circuits, 4
0 and 41 are soft switch circuits, 50 is a motion detection circuit,
Reference numerals 60 and 61 are line delay circuits, 70 is a Y-adaptive scanning line conversion circuit for converting a luminance signal into a line, 80 is a C adaptive scanning line conversion circuit for performing a line conversion of a carrier color signal, and 90 is an addition circuit.
A signal control circuit 100 controls the delay time of the tapped delay circuit 20, the signal processing of the Y adaptive control circuit 70, and the C adaptive control circuit 80.

Composite video signal A1V input from terminal 1
Is input to the line C comb filter 10 and the carrier color signal is separated and output. Here, as an example, a so-called three-line adaptive C-comb filter is used, in which signals of three adjacent lines are used to adaptively separate the patterns. Fig. 2 shows the composite video signal currently input from terminal 1.
Then, it is set to A1V. The carrier color signal C1C separated by the line C comb filter 10 is at a position delayed by one line with respect to the composite video signal A1V. The separated carrier color signal C1C is input to the soft switch circuit 40. Further, C1 shown in FIG. 2 having the same delay time as the carrier color signal C1C separated from the line C comb filter 10
The composite video signal C1V at the position is output. The composite video signal C1V is input to the delay circuit with tap 20 and the subtraction averaging circuit 30.

The composite video signal C1V input from the first tap of the delay circuit with taps 20 is delayed by one field from the composite video signal B2V at the position B2 in FIG.
Is output. The composite video signal B2V output from the first tap is input to the line C comb filter 11, and the carrier color signal D2 corresponding to the position D2 in FIG.
C is output. Then, it is input to the soft switch circuit 41. Further, the composite video signal D at the position D2 in FIG. 2 having the same delay time as the separated carrier color signal D2C.
2V is output and input to the subtraction averaging circuits 31 and 34.

2 from the second tap of the tapped delay circuit 20 to the input signal C1V of the tapped delay circuit 20.
The field-delayed composite video signal C3V at the position C3 shown in FIG. 2 is output. The composite video signal C3V is input to the subtraction averaging circuit 30 and is subtracted from the composite video signal C1V and averaged to form a frame C comb filter. The carrier color signal output from the subtraction averaging circuit 30 is input to the soft switch circuit 40.

The soft switch circuit 40 carries the carrier color signal C1C separated by the line C comb filter 10 and the carrier color signal C1C separated by the frame C comb filter composed of the delay circuit 20 with taps and the subtraction averaging circuit 30. A color signal is input. When there is no movement in the picture, the output signal of the frame C comb filter is selected, and when the movement is large, the output signal of the line C comb filter 10 is selected.
The selection of this signal is controlled by a control signal output from a motion detection circuit 50, which will be described later, and both signals are mixed and output at a predetermined mixing ratio according to the amount of motion. That is, assuming that the output signal of the line C comb filter is LC, the output signal of the frame C comb filter is FC, and the coefficient indicating the magnitude of the motion amount is a, the soft switch circuit 40
The output signal SC of is expressed by the following equation.

[0013]

## EQU1 ## SC = a.LC + (1-k) .FC However, the coefficient k indicating the magnitude of the motion amount is 0 when there is no motion, and 1 when the motion is large, depending on the motion amount. Takes a value of 0 to 1.

The output signal C1SC at the position C1 of the soft switch circuit 40 is input to the C adaptive scanning line conversion circuit 80, the line delay circuit 60, and the subtraction circuit 33. The line delay circuit 60 delays the signal for one horizontal scanning period,
Signal E1SC at the E1 position of C is applied to the C adaptive scan line conversion circuit 8
Input to 0. From the third tap of the tapped delay circuit 20, a composite video signal D4V corresponding to the position D4 of FIG. 2 delayed by 3 fields from the input signal C1V of the tapped delay circuit 20 is output, and is output to the subtraction averaging circuit 31. Is entered. The composite video signal D4V is subtracted from the composite video signal D2V input to the subtraction averaging circuit 31 and averaged to form a frame C comb filter.

The output signal of the subtraction averaging circuit 31 is input to the soft switch circuit 41. Soft switch circuit 41
Operates similarly to the soft switch circuit 40, the control signal from the motion detection circuit 50 is input, and the output signal D2C of the line C comb filter 11 and the output signal of the frame C comb filter are mixed and added according to the amount of motion. And output. The output signal D2SC corresponding to the position D2 of the soft switch circuit 41 is the C adaptive scan line conversion circuit 80, the subtraction circuit 3
Input to 4.

Further, the composite video signal C1V input to the tapped delay circuit 20 is input to the subtraction circuit 33.
Carrier color signal C1 output from the soft switch circuit 40
SC is also input to the subtraction circuit 33, and the composite video signal C1
Subtracted from V. From the subtraction circuit 33, the position C1 in FIG.
Is output to the line delay circuit 61 and the Y adaptive scanning line conversion circuit 70. In the line delay circuit 61, the luminance signal C1Y is delayed for one horizontal scanning period, and the luminance signal E1Y corresponding to the position E1 in FIG. 2 is output and input to the Y adaptive scanning line conversion circuit 70. Further, the subtraction circuit 34 receives the composite video signal D2V and the carrier color signal D2SC corresponding to the position D2 in FIG.
The luminance signal D2Y is output from the input terminal to the Y adaptive scanning line conversion circuit 70.

The Y adaptive scanning line conversion circuit 70 has been inputted with the luminance signals corresponding to the positions C1, D2 and E1 shown in FIG. In the Y-adaptive scanning line conversion circuit 70, if a still image is determined by the control signal from the motion detection circuit 50, scanning line conversion is performed using a signal between fields, and if it is determined to be a moving image, Scan line conversion is performed using both signals between fields and between lines. When performing field conversion from an odd field to an even field or vice versa, scanning line conversion is performed so as to obtain a signal between positions D2 and E1 in FIG. If the motion detection circuit 50 determines that the signal is Y3S when it is determined that there is no motion,

[0018]

## EQU2 ## Y3S = m.D2Y + (1-m) .E1Y. Here, m is a coefficient that determines the characteristics of the scanning line conversion filter, and takes a value of 0 to 1. Motion detection circuit 50
If it is determined that there is a large movement in the
Let M. The signal Y3M is represented by the formula of FIG. 10 described later.

If the coefficient indicating the magnitude of the motion amount is a and the signal thereof is Y3,

[0020]

## EQU3 ## Y3 = a.Y3M + (1-a) .Y3S.

When converting from an odd field to an odd field, or from an even field to an even field, scanning line conversion is performed so as to obtain a signal between positions C1 and D2 in FIG. If the motion detection circuit determines that there is no motion and the signal is Y1S,

[0022]

## EQU4 ## Y1S = m.C1Y + (1-m) .D2Y. When the motion detection circuit 50 determines that there is a large motion, the signal is set to Y1M. The signal Y1M is
It is represented by the formula of FIG. 10 described later.

If the coefficient indicating the magnitude of the motion amount is a and the signal is Y1, then

[0024]

## EQU5 ## Y1 = a.Y1M + (1-a) .Y1S.

The carrier color signals corresponding to the positions C1, D2 and E1 shown in FIG. 2 are input to the C adaptive scanning line conversion circuit 80. The control signal from the motion detection circuit 50 is input to the C-adaptive scanning line conversion circuit 80. In the case of a still image without motion, field conversion is performed using a signal between fields, and when there is motion, the field conversion is performed. Field conversion is performed using signals between lines and lines. The operation of the C adaptive scan line conversion circuit 80 is similar to that of the Y adaptive scan line conversion circuit 70. In the case of the NTSC signal, since the frequency of the color subcarrier is an odd multiple of half the horizontal scanning frequency, the phase of the color subcarrier is inverted at the position C1 and the positions D2 and E1. Therefore, with respect to the signal at the position C1, the positions D2 and E1 are
By inverting the phase of the signal of, the conversion can be performed by the same processing as the Y adaptive scanning line conversion circuit 70.

The C adaptive scan line conversion circuit 80 requires a phase inversion circuit and its control circuit after the scan line conversion. In the case of the NTSC signal, the frequency of the color subcarrier is selected to be an odd multiple of the horizontal scanning frequency, as described above, so that the phase of the carrier color signal is inverted between lines in the portion where the hue does not change. From this relationship, control is performed to invert the phase of the carrier color signal so as to match the phase of the color subcarrier of the converted field, or to stop the inversion. These controls are performed based on a control signal from the signal control circuit 100. The field number of the reproduced video signal input from the terminal 3 is compared with the field number of the output video signal input from the terminal 4, and the conversion control is performed based on the relationship between them. Table 1 summarizes the control.

[0027]

[Table 1]

In Table 1, 1/4 represents scan line conversion to the same scan line, and 3/4 represents conversion to different scan lines.

The luminance signal and the carrier color signal converted as described above are input to the adding circuit 90 and added to produce a field-converted composite video signal, which is output from the terminal 2.

The output of the subtraction averaging circuit 30 is input to the motion detection circuit 50. In the case of a signal having no motion, the carrier color signal has its phase inverted between frames, and the luminance signal has no change in amplitude, so the luminance signal is removed by subtraction, and only the carrier color signal is output. Therefore, the motion of the luminance signal can be detected by removing the carrier color signal component from the output of the frame C comb filter. Specifically, a motion signal of a luminance signal can be obtained by passing the output of the frame comb filter through a low pass filter.

Further, the composite video signal C1V is inputted to the subtraction averaging circuit 32. Fourth tap delay circuit 20
The composite video signal C5 corresponding to the position C5 in FIG. 2 delayed by 4 fields from the tap of the composite video signal C1V
V is output and input to the subtraction averaging circuit 32. Composite video signals C1V and C5V input to the subtraction averaging circuit 32
Difference signal is output from the subtraction averaging circuit 32 and input to the motion detection circuit 50. In a signal having no motion, the carrier color signal has the same phase between the two frames and the luminance signal has the same amplitude. Therefore, the difference between the two can detect the motion of the luminance signal and the carrier color signal. According to the present embodiment, since the field conversion processing is performed using the signal between fields in the still image portion, the conversion from the odd field to the even field and vice versa and the conversion from the odd field to the odd field are performed. The change of the center of gravity is eliminated in the case of the conversion to or the conversion from the even field to the even field, and the field conversion processing which is extremely stable visually can be performed.

Further, the level of the luminance signal having no motion does not change between frames, whereas the phase of the carrier color signal having no motion is inverted between frames, so the average difference between the signals between frames is calculated. By taking it, the carrier color signal can be separated. As a result, it is not necessary to limit the band having the comb filter characteristic, and thus the line Y /
It is possible to separate the luminance signal and the carrier color signal without deterioration of the diagonal resolution such as the C-separating comb filter. Further, since it is not necessary to limit the comb band in the frame comb filter, the luminance signal and the carrier color signal can be reliably separated even in the horizontal transient portion of the color signal, and the carrier color signal component remaining in the luminance signal is eliminated. Therefore, color flicker can be eliminated.

Details of the motion detection circuit 50, the Y adaptive conversion circuit 70, and the C adaptive conversion circuit 80 will be described below with reference to the drawings. FIG. 3 is a block diagram showing a configuration example of the motion detection circuit 50. In FIG. 3, 501 is an input terminal for inputting a signal from the subtraction averaging circuit 30, 5
Reference numeral 02 is an input terminal for inputting a signal from the subtraction averaging circuit 32, 503 is an input terminal for a control signal from the signal control circuit 100, 504 to 506 are output terminals for a signal indicating the presence or absence of movement and an amount, and 510 is an input terminal. A motion synthesis circuit for detecting motion from signals input from 501 and 502, 520 is a space-time filter, 530 is a control circuit, 540 is a low-pass filter, and 541 is a band-pass filter.

From the terminal 501, a signal obtained by averaging the differences between the signals before and after one frame is input. From this signal,
The motion of the luminance signal can be detected by removing the component in the carrier color signal band. The LPF 540 is a filter for removing the carrier color signal component, receives the signal from the terminal 501, and outputs a signal for detecting the movement of the luminance signal.
From the terminal 502, a signal obtained by averaging the differences between the signals before and after two frames is input. As described above, the motion of the luminance signal and the carrier color signal can be detected from this signal, but it is possible to detect the motion of only the carrier color signal component by limiting the band as necessary. The BPF 541 is a filter therefor. The outputs of the LPF 540 and BPF 541 are input to the motion synthesis circuit 510.

In the motion synthesizing circuit 510, the respective inputted signals are compared in level as necessary, and the larger value is taken as a motion signal. Further, in the case of thinning reproduction described later, when a control signal indicating that the field is thinned is input from the terminal 503, when there is no difference between the signals before and after one frame, there is no difference in the signals. It is assumed that the motion is detected only by the difference between the signals before and after the two frames, and when the difference between the signals before and after the two frames cannot be obtained, the motion is detected only by the difference between the signals before and after one frame. A gate signal for gated the output signal of is input. Further, the output of the motion synthesis circuit 510 is input to the spatiotemporal filter 520. The spatiotemporal filter expands the output from the motion synthesizing circuit in the adjacent space and in the time direction to dull the output, and deteriorates the image quality due to the abrupt change in the motion amount near the boundary between the still image and the moving image. Can be prevented. An example of such a spatiotemporal filter is disclosed in Japanese Patent Application No. 3-13790.

The output of the spatiotemporal filter 520 is input to the control circuit 530 and distributed, and at the same time, the terminal 50
A signal output to the soft switch circuits 40 and 41 is gated on the basis of the signal indicating the field thinning input from 3. The output of the control circuit 530 is the terminals 504 to 50.
6 is output as an output signal of the motion detection circuit 50. Next, the scanning line conversion process in the moving image portion used in the Y adaptive conversion circuit 70 will be described.

As described in FIG. 1, the motion detection circuit 50
The signal movement is detected by, and the scan line conversion processing is performed using the signal between fields in the apparent still image portion. However, the motion detection circuit 50 may determine a moving image regardless of a still image. For example, when a point of interest that is stationary moves nearby, the motion is spatially spread by the spatiotemporal filter shown in FIG. 3, so the point of interest is also detected as moving. The present invention can realize scanning line conversion even in this case without image quality deterioration.

FIG. 4 is a block diagram of the scanning line conversion processing circuit in the moving image portion of the Y adaptive conversion circuit 70. In FIG. 4, reference numeral 200 surrounded by a broken line is a moving image scanning line conversion circuit, 201 is an input terminal of data (E1 in FIG. 2) A of the previous line, 2
Reference numeral 02 is an input terminal for data B (corresponding to C1 in FIG. 2) of the current line, and 203 is data C (corresponding to D2 in FIG. 2) interlacing between data A and data B in the previous field.
, An input terminal of a signal for controlling field conversion from the signal control circuit 100, an output terminal of a luminance signal processed by the Y adaptive conversion circuit 70, and 212 to 21.
5 is a switching circuit, and 227 to 229 are coefficient units, 237 and 23.
8 is an adder, 234 and 235 is a subtractor, 240 is a comparison circuit that compares the magnitudes of the data A, B, and C, 241 is a comparison circuit that compares the input data and outputs the smaller data, 242 Reference numeral 250 is an inter-line signal processing circuit, 260 is an inter-field signal processing circuit, and 270 is a boundary signal processing block.

First, the signal processing when the level of the data C input from the terminal 203 is much higher or lower than the level of the data A and B input from the terminals 201 and 202 will be described. The motion detection circuit 50 shown in FIG. 1 determines that it is a moving image, and in such a state, it can be clearly determined that it is a moving image. In this case, the inter-line signal processing circuit 250 performs signal processing by an interpolation filter using the inter-line data so that an afterimage is not generated. FIG. 5 shows an example of the line signal processing circuit 250 of FIG. In FIG. 5, 201 is the input terminal of the previous line data (E1 in FIG. 2) A, 202 is the input terminal of the current line data (C1 in FIG. 2) B, and 203 is the previous field of data A and data B An input terminal for data C (corresponding to D2 in FIG. 2) interlaced between is a signal input terminal for controlling field conversion from the signal control circuit 100, 205 is an output terminal of the interline signal processing circuit 250, and 210 is Switching circuit, 220 to 223 are coefficient units,
230 and 231 are adders.

The data A input from the input terminal 201 is multiplied by a predetermined coefficient by the coefficient units 221, 222, and the data B input from the input terminal 202 is multiplied by a predetermined coefficient by the coefficient units 220, 223, respectively. The coefficient value is, for example, the coefficient unit 22.
0 and 222 are set to 1/4, and coefficient multipliers 221 and 224 are set to 3/4. After that, the outputs of the coefficient unit 220 and the coefficient unit 221 are added by the adder 230, and the outputs of the coefficient unit 222 and the coefficient unit 223 are added by the adder 231. Switching circuit 210
Are switched by a signal input from the terminal 204, which indicates whether the fields of the reproduced video signal and the output video signal are odd or even, or not. When the fields of the reproduced video signal and the output video signal are odd and even, the adder 230
Output is selected, and when the reproduced video signal and the odd and even fields of the output video signal match, the adder 2
31 outputs are selected. This interpolation filter passes through filters with the same frequency and amplitude characteristics regardless of whether the fields are odd or even, and does not match, so there is no flicker due to the difference in resolution, and a relatively good image with no afterimage can be obtained even in moving images. Be done.

Next, the signal processing when the level of the data C is between the data A and B will be described. In this case, even if the motion detection circuit 50 shown in FIG. 1 determines that there is motion, the possibility of a still image is actually high. In the above case, the inter-field signal processing circuit 260 performs signal processing using inter-field data. FIG. 6 shows an example of the inter-field signal processing circuit 260 shown in FIG. In FIG.
Reference numeral 201 denotes an input terminal for data of a previous line (corresponding to E1 in FIG. 2) A, 202 denotes an input terminal for data of the current line (corresponding to C1 in FIG. 2) B, and 203 denotes data for a previous field A.
And data C that interlace between data and data B (D in FIG.
2), 204 is an input terminal of a signal for controlling field conversion from the signal control circuit 100, 205
Is an output terminal of the line signal processing circuit 250, 211 is a switching circuit, 224 to 226 are coefficient units, 232 and 233 are adders.

In FIG. 6, data A, data B, and data C are input to the coefficient multipliers 224, 226, and 225, respectively, and multiplied by a predetermined coefficient. The coefficient value is determined so that the frequency-amplitude characteristic of the interpolation filter used for the signal processing between lines and the shift of the center of gravity of the image do not occur. In the present embodiment, as an example, the coefficients of the coefficient multipliers 224, 225, 226 are all halved. Coefficient multiplier 224 and coefficient multiplier 2 in adder 232.
The output of No. 25 is the coefficient unit 225 and the coefficient unit 2 at the adder 233.
The 26 outputs are added together. Similar to the switching circuit 210 described above, the switching circuit 211 is switched by a signal which is inputted from the terminal 204 and indicates whether the fields of the reproduced video signal and the output video signal are the same or not. Odd number of fields of playback video signal and output video signal,
When the even numbers do not match, the output of the adder 232 that performs the operation of (A + C) / 2 is selected, and when the odd and even numbers of the fields of the reproduced video signal and the output video signal match,
The output of the (B + C) / 2 adder 233 is selected.

FIG. 7 is a diagram showing a state of inter-field signal processing at a luminance edge. FIG. 7 (a) shows a reproduced signal,
FIG. 5B shows the case where the odd and even fields of the reproduced signal field and the output signal match, and FIG. 7C shows the case where the odd and even fields of the reproduced signal field and the output signal do not match. It is the figure shown. In the case of the inter-field processing, the position of the luminance edge is as shown in FIG. 7 when the odd and even fields of the reproduced signal and the output signal are the same.
When the positions indicated by broken lines in (b) and the odd and even numbers of fields do not match, the positions are indicated by broken lines in FIG. 5C, and the positions of both luminance edges are the same. Therefore, it is possible to obtain an image in which there is no vertical play in the luminance edge portion.

FIG. 8 is a diagram showing the principle of the signal processing between the lines and between the fields described above. FIG. 8A shows the signal processing between the lines and FIG. 8B shows the signal processing between the fields. There is. In line signal processing, data A and data B
In the calculation using, the center of gravity of the image is moved to the 1/4 and 3/4 points between the lines due to the match and mismatch of the odd and even fields of the reproduction signal and the output signal. on the other hand,
In the inter-field signal processing, the data B is transmitted depending on whether the fields of the reproduction signal and the output signal match or do not match.
And the calculation result of the data C and the calculation result of the data A and the data C are output. In this case as well, the center of gravity of the image becomes 1/4 and 3/4 points between the lines due to odd and even coincidences and non-coincidences of the fields of the reproduction signal and the output signal, respectively. The center of gravity of the image does not deviate due to the difference in signal processing.

As described above, whether the scan line conversion is performed by using the data between fields or the scan line conversion is performed by using the data between lines is performed. The data C (data interlaced between the data A and the data B) are compared with each other. If the value of the data C is between the value of the data B and the value of the data A, it can be considered as a still image, and if the value of the data C is not between the value of the data B and the value of data A, it is clearly a moving image. Can be regarded as

FIG. 9 shows the line signal processing circuit 250.
The inter-field signal processing circuit 260 and the comparison circuit 240.
It is the result of operation according to the control signal from. As an example, in the case of (A> B), the value of the data A of the previous line is 1 and the value of the data B of the current line is 0, which are normalized and displayed. The horizontal axis shows the normalized value of the data C in the previous field, and the vertical axis shows the normalized data value after the field conversion processing. Also, the solid line shows the case where the odd and even fields of the reproduced signal and the output signal match, and the broken line shows the case where the odd and even fields of the reproduced signal and the output signal do not match. In the comparison circuit 240, if the value of the data C is 0 or more and 1 or less, it is determined to be a still image, and otherwise, it is determined to be a moving image. Since the above-mentioned inter-field processing is performed in the still image portion, calculation is performed using data C and data A or data C and data B. Therefore, as shown in FIG. 9, the value of the output data changes depending on the value of the data C.
On the other hand, when it is determined to be a moving image, the value of the output data is irrelevant to the value of the data C because the inter-line processing is performed and only the data A and the data B are calculated. Figure 9
As shown in (a), at the boundary between the moving image and the still image,
The value of the output data changes discontinuously, and the image appears rough in the vertical edge portion.

Therefore, in order to reduce the roughness of the image at the boundary between the inter-line signal processing and the inter-field signal processing, switching of the signal processing is smoothly connected as shown in FIG. 9B, that is, a moving image and a still image. At the border of
Make the switch with a certain width (shown with diagonal lines). FIG. 10 is a diagram collectively showing an example of the signal processing that realizes the operation shown in FIG. 9B. By changing the value of the coefficient k of the arithmetic expression shown in FIG. )
It is possible to change the width of the boundary part shown by the broken line in the inside. The signal processing shown in FIG. 10 can be implemented by the boundary signal processing block 270 of FIG.

In the boundary signal processing block 270 of FIG. 4, the switching circuit 212 is switched and matched by a signal input from the terminal 204 and indicating whether the fields of the reproduction signal and the output signal are the same or not. In the case, the data B is output to the output 1 and the data A is output to the output 2, and when they do not match, the data A is output to the output 1 and the data B is output to the output 2. The output 1 of the switching circuit 212 is subtracted from the previous field data C by the subtractor 234, multiplied by k in the coefficient unit 227, and added to the output 1 of the switching circuit 212 in the adder 237. This output corresponds to the equation D1 shown in FIG. On the other hand, the output 2 of the switching circuit 212 is subjected to subtraction by the subtractor 235 with the data C of the previous field, then multiplied by k in the coefficient unit 228 and sent to the adder 238. At the same time, the output 1 and the output 2 of the switching circuit 212 are added by the adder 236, then multiplied by ½ by the coefficient unit 229, and added by the adder 238 with the output of the coefficient unit 228. This output corresponds to the equation D3 shown in FIG. The output D1 of the adder 237 and the output D3 of the adder 238 are input to the switching circuit 213. The switching circuit 213 switches according to the output signal from the comparison circuit 240. In the case of (A> B), the switching circuit 213 switches to output D1 to the output 1 and D3 to the output 2 of the switching circuit 213, and (A <B). Switches to output D3 to the output 1 and D1 to the output 2 of the switching circuit 213. The comparison circuit 241 includes a switching circuit 21.
Output 1 of 3 and the result of the above-described inter-line signal processing circuit 250 are input, and the smaller one of them is output. Further, the output 2 of the switching circuit 213 and the result of the above-described line signal processing circuit 250 are input to the comparison circuit 242,
The larger of them is output. This comparison circuit 24
1 and 242, a certain width can be provided by the coefficient k at the switching point between the inter-line signal processing (moving image portion) and the inter-field signal processing (still image). Comparison circuit 24
The outputs of 1 and 242 are input to the switching circuit 214, and
As shown in 0, the data A, B, and C are appropriately switched depending on the magnitude relationship. By the boundary signal processing block 270 shown in FIG. 4 described above, it is possible to gradually switch between the inter-line signal processing and the inter-field signal processing at the boundary between the moving image and the still image.

The outputs of the inter-field signal processing circuit 260 and the boundary signal processing block 270 described above are input to the switching circuit 215 and switched by the output of the comparison circuit 240. The output of the signal processing circuit 260, and when it is determined to be a moving image, the output of the boundary signal processing block 270 (the output obtained by connecting the line signal processing and the boundary signal processing) is selected and output.

In the Y-adaptive conversion circuit 70 shown in FIG. 1, the inter-field signal processing in the portion judged to be a still image by the motion detection circuit 50 is carried out by the inter-field signal processing circuit 260 when m = 0.5. In this case, the output of the inter-field signal processing circuit 260 may be used.

The C adaptive conversion circuit 80 is the same as the process of the Y adaptive circuit 70 except that the phase inversion processing is performed in consideration of the phase of the color subcarrier as described above.
The same applies to the video signal processing circuit included in the C adaptive conversion circuit 80. The luminance signal and the chrominance signal, which have been field-converted by the Y adaptive conversion circuit 70 and the C adaptive conversion circuit 80 described above, are added by the adder 90 and output from the output terminal 2 as a composite signal.

Next, signal processing in the case of thinning out the screen of one field for every several fields in order to shorten the reproduction time will be described. FIG. 12 is a diagram showing the positions of signals for explaining the operation in that case.

In FIG. 11, the field number currently being reproduced is 1. It is assumed that the field 2 is skipped and reproduced in order to shorten the reproduction time. At least the preceding 3, 4, and 5 fields are assumed to be continuously reproduced. In this case, since field 2 is skipped and reproduced, Y / C separation processing cannot be performed by the frame comb filter using 2 fields and 4 fields. In this case, the Y / C separation processing between lines is performed using only the signals of 4 fields. Similarly, motion detection using 2 fields and 4 fields cannot be performed. In this case, signal processing is performed assuming that there is no movement between the 2nd and 4th fields. Alternatively, the motion signal of the previous field is multiplied by a coefficient and processed as a motion signal of this field.

Specifically, the following signal processing is performed. From the first tap of the delay circuit with taps 20 in FIG. 1, two fields are delayed with respect to the input video signal C1V (corresponding to a substantial three field delay because field 2 is originally skipped and reproduced). The composite video signal B4V at the position B4 in FIG. 12 for racing is output. Similar to the case of FIG. 2, the second, third, and fourth taps output the composite video signal C3V at the position C3, the composite video signal D4V at the position D4, and the composite video signal C5V at the position C5. By doing so, the carrier color signal D4C at the position D4 is output from the line C comb filter 11. In the signal control circuit 100, input from the terminal 3,
The continuity of the reproduction field numbers is checked, and in the field immediately after the field jump, the motion detection circuit 50 controls the soft switch circuit 41 to forcibly enter the motion mode.

FIG. 12 is a diagram showing the signal processing in the case of one field after the field shown in FIG.
This means that the signal two fields before the current field was skipped and reproduced. In this case, since there is no 3-field signal, it is not possible to perform signal processing using the 1-field and 3-field signals. Y / C separation is
Y / C separation processing between lines is performed using only one field signal. The motion detection uses the signals of the 1st and 5th fields to detect the motion. Signal processing is performed assuming that there is no movement between the 1st and 3rd fields.

Specifically, the following signal processing is performed. From the first, third, and fourth taps of the tapped delay circuit 20 of FIG. 1, signals B2V, D4V, and C5V are respectively output to the input video signal C1V. Based on the control signal from the signal control circuit 100, the motion detection circuit 5
At 0, the soft switch circuit 40 is controlled to be forced into the motion mode. The output signal of the subtraction averaging circuit 30 is forcibly controlled by the motion detection circuit 50 to be 0.

FIG. 13 is a diagram showing signal processing in the case of one field after the field shown in FIG. This means that the signal three fields before the current field was skipped and reproduced. In this case, since there is no 4-field signal, it is not possible to perform signal processing using the 2-field and 4-field signals. Y / C separation uses only the signals of 2 fields to perform Y / C between lines.
Perform separation processing.

Specifically, the following signal processing is performed. From the first, second, and fourth taps of the tapped delay circuit 20 of FIG. 1, signals B2V, C3V, and C5V are respectively output to the input video signal C1V. Based on the control signal from the signal control circuit 100, the motion detection circuit 5
At 0, the soft switch circuit 41 is forcibly set to the motion mode.

FIG. 14 is a diagram showing the signal processing in the case of one field after the field shown in FIG. This means that the signal four fields before the current field was skipped and reproduced. In this case, since there is no signal of 5 fields, the signal processing performed using the signals of 1 field and 5 fields cannot be performed. Signal processing is performed assuming that there is no movement between two frames.

Specifically, the following signal processing is performed. From the first, second, and third taps of the tapped delay line 20 of FIG. 1, signals B2V, C3V, and D4V are output to the input video signal C1V, respectively. Based on the control signal from the signal control circuit 100, the subtraction averaging circuit 3
The output signal 2 is forcibly controlled by the motion detection circuit 50 to be 0.

If the next field is continuously reproduced, the normal state shown in FIG. 2 is restored. When the next field is thinned out, the state shown in FIG. 11 is entered, and the above signal processing is repeated. The above-mentioned signal processing can be performed if the thinning-out of the fields is performed once for every five fields.

Table 2 is a table summarizing the above signal processing.

[0063]

[Table 2]

Table 3 is a table showing the output signal of each tap of the delay line with taps.

[0065]

[Table 3]

Next, the signal processing when the same field is repeated in the slow reproduction will be described.
FIG. 15 is a diagram for explaining this, and is a diagram when one field is repeatedly reproduced.

In FIG. 15, signals A1 and A1 ', C1
And C1 'and E1 and E1' are signals on the same line in the same field. In this case, the signals B2V, C3V, D4V, and C5V are output from the first, second, third, and fourth taps of the delay circuit with tap 20 of FIG.
At this time, the signal A1 'of the field currently reproduced is not written in the delay circuit with tap 20, and the already written signals (signals of 1 to 5 fields) are held as they are.

When the signal of the same field is reproduced again after one field, the signal processing is performed in the same manner as in FIG. The same signal processing is performed as long as the same field is repeated. That is, even in the case of freeze signal processing, signal processing can be similarly performed. When the next field is reproduced, the same signal processing as shown in FIG. 2 is performed, and normal signal processing is performed. That is, the slow reproduction can be realized. In particular, in the case of slow reproduction, signals of two fields that are interlaced are used to create a signal of a new field, so that not only the center of gravity does not fluctuate, but also the vertical resolution does not deteriorate. For example, the diagonal lines are not jagged, and the image quality can be significantly improved.

Next, the case of reverse reproduction will be described.
In the case of reverse reproduction, the phase of the color subcarrier of the carrier color signal differs from that in normal reproduction. In FIG. 1, the phase of the color subcarrier of the signal D2SC output from the soft switch 41 is inverted.
In FIG. 1, a mode signal from a system controller or the like is fetched from a terminal 5 and a signal D2SC is supplied during reverse playback.
The signal processing is performed by inverting the phase of. The signal processing other than the phase inversion of the signal D2SC is the same as the normal reproduction.

FIG. 16 is a block diagram showing an example of the delay circuit 20 with a tap. 16, the same parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. 110 is a video signal input terminal of the delay circuit with a tap 20, 111-1
Reference numeral 14 is an output terminal from each of the first to fourth taps of the delay circuit 20 with taps, 120 to 124 are field memories, 131 to 134 are switching circuits, and 140 to 144 are timings for writing signals to the field memories 120 to 124, respectively. Input terminal of write control signal for controlling
154 are input terminals for reading control signals for reading control, and 161 to 164 are switching circuits 131 to 134, respectively.
A switching control signal input terminal for switching control is indicated by 170, and a control signal input terminal 170 is for controlling writing of the video signal in the field memories 120 to 124.

The continuity of the field numbers of the reproduced video signal input from the terminal 3 is checked, and when the field numbers are discontinuous, delay control is performed so that the signals shown in Table 3 are output from each tap. Output a signal.
The control signal is used as a write control signal for the terminals 140 to 14
4, the read control signal is input to the terminals 150 to 154, and the switching control signal is input to the terminals 161 to 164.

The field memory has a memory capacity of about 1 field. For example, in the case shown in FIG. 11, the video signal B4V delayed by 2 fields output from the first tap 111 is output from the field memory 121 by the switching circuit 131.
It is possible to obtain the signal from the first tap 111 by selecting the signal input to the switch circuit and outputting the selected signal.

Similarly, the video signals shown in Table 3 can be output from the respective taps by controlling the switching circuits 131 to 134.

Next, a case will be described in which one field in a continuous video signal is repeatedly reproduced at least twice or more in order to adjust the reproduction time or perform slow reproduction. When the field 1 is reproduced twice in succession, the signal control circuit 100 shown in FIG.
It is identified from the reproduction field number input by the input that the same field has been input twice in succession. The control signal from the signal control circuit 100 is input to the delay circuit with tap 20 and input to the terminal 170 shown in FIG. 16 to stop the writing of the signal to the field memories 120 to 124. At this time, the switching circuits 131 to 134 are respectively arranged in FIG.
As described with reference to the signals B2V, C3V, D4
V and C5V are selected and output. 2 identical fields
This is also the case when the data is reproduced over more than one field, and while the same field continues, the field memory 12
Signal processing can be performed by stopping the writing to 0 to 124.

Although the embodiment shown in FIG. 1 shows the case where the composite video signal is reproduced, when the component signals such as the luminance signal and the color difference signal are reproduced,
It is not necessary to separate the luminance signal and the carrier color signal. Moreover,
As the output, it is sufficient to output the luminance signal and the color difference signal,
The adder circuit 90 is also unnecessary. Even in this case, it is obvious that the scanning line conversion circuit according to the present invention can be used.

[0076]

According to the present invention, since the field conversion processing between fields is performed for the still picture portion of the reproduced video signal, when the field thinned portion or the same field is continuously reproduced. Also, it is possible to eliminate the movement of the center of gravity due to the field conversion processing. Furthermore, since the Y / C separation processing between frames can be performed on the still image portion of the reproduced video signal, deterioration of the diagonal resolution of the luminance signal can be eliminated by the field conversion processing. Further, since the Y / C separation between frames does not need to limit the separation band of the luminance signal and the carrier color signal, the carrier color signal does not remain in the luminance signal, and the conventional color signal in the luminance signal prevents the carrier color signal from remaining. It is possible to eliminate the generated color flicker. On the other hand, in the moving image portion, the Y / C separation processing is the same as the conventional one, but the scanning line conversion processing is performed when the signal levels of different fields fall between the signal levels of adjacent lines and when they do not fall. And the case is different. When the signal levels of different fields fall between the signal levels of the adjacent lines, the signal between the fields is used to perform the scan line conversion.
Scan line conversion can be performed without rattling of vertical edges.
Further, since the signal level of the scanning line after conversion becomes a value between adjacent lines, it does not become an abnormal signal and an afterimage does not occur. Further, when the signal levels of different fields do not fall within the signal levels of adjacent lines, scan line conversion is performed using only the signal between lines, so that an afterimage does not occur. With the above effects, the image quality during special reproduction can be significantly improved.

[Brief description of drawings]

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

FIG. 2 is an operation explanatory diagram of the present invention.

FIG. 3 is a block diagram showing details of a motion detection circuit.

FIG. 4 is a block diagram showing details of scanning line conversion processing in a moving image portion of a Y adaptive conversion circuit 70.

FIG. 5 is a block diagram showing details of an inter-line signal processing circuit.

FIG. 6 is a block diagram showing details of an inter-field signal processing circuit.

FIG. 7 is a signal processing diagram for explaining inter-field signal processing.

FIG. 8 is an explanatory diagram of the principle of inter-line signal processing and inter-field signal processing.

FIG. 9 is a diagram illustrating the principle of boundary signal processing.

FIG. 10 is a diagram summarizing signal processing operations of boundary signal processing.

FIG. 11 is an explanatory diagram of the operation of the present invention.

FIG. 12 is an operation explanatory diagram of the present invention.

FIG. 13 is an explanatory diagram of the operation of the present invention.

FIG. 14 is an operation explanatory diagram of the present invention.

FIG. 15 is an operation explanatory diagram of the present invention.

FIG. 16 is a block diagram showing details of a tapped delay circuit according to the present invention.

[Explanation of symbols]

 10, 11 ... Line C comb filter 20 ... Delay circuit with taps 30-32 ... Subtraction averaging circuit 33, 34 ... Subtraction circuit 40, 41 ... Soft switch circuit 50 ... Motion detection circuit 60, 61 ... Line delay circuit 70 ... Y adaptive conversion circuit 80 ... C adaptive conversion circuit 90 ... Addition circuit 100 ... Signal control circuit 120-124 ... Field memories 161-164 ... Switching circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Yoshizawa 292 Yoshida-cho, Totsuka-ku, Yokohama City Hitachi Media Imaging Laboratory (72) Inventor Toshiaki Takahashi 4th Kanda Surugadai, Chiyoda-ku, Tokyo Stock company Within Hitachi

Claims (4)

[Claims] 1. A field conversion circuit for converting a video signal of an arbitrary field number into an input signal and converting the video signal of the arbitrary field number to output so as to match a standard television signal. A first motion adaptive Y / C separation circuit for separating a luminance signal and a carrier color signal, and a luminance signal and a carrier color signal of different fields interlacing the separated luminance signal and carrier color signal. A second motion adaptive Y / C separation circuit; a motion detection circuit for detecting the presence or absence of motion of the input video signal; a luminance signal separated by the first motion adaptive Y / C separation circuit; A still image scanning line conversion circuit for a luminance signal, which receives the luminance signal separated by the second motion adaptive Y / C separation circuit and performs still image processing when the motion detection circuit determines that the image is a still image. Motion detection is performed on the luminance signal moving image scanning line conversion circuit, which performs moving image processing when the motion detection circuit determines that the image is a moving image, the still image scanning line conversion circuit output, and the moving image scanning line conversion circuit output. A luminance signal adaptive conversion circuit having: a synthesizing circuit for appropriately synthesizing by changing a mixing ratio according to a motion signal from the circuit; and a carrier color signal separated by the first motion adaptive Y / C separation circuit. And a carrier color signal separated by the second motion adaptive Y / C separation circuit as an input, and still image processing is performed when the motion detection circuit determines that the image is a still image. A line conversion circuit, a moving image scanning line conversion circuit for carrier color signals, which performs moving image processing when it is determined to be a moving image by the motion detection circuit, an output of the still image scanning line conversion circuit, and the moving image scanning line conversion circuit. Output from the motion detection circuit A carrier color signal adaptive conversion circuit having a combining circuit that appropriately changes the mixing ratio according to the signal, and an output signal of the luminance signal adaptive conversion circuit and an output signal of the carrier color signal adaptive conversion circuit. And an adder circuit for adding and, and the output of the adder circuit is an output video signal after conversion. 2. The moving picture scanning line conversion circuit receives an arbitrary data B in a field to be subjected to field conversion, data A 1H before data B, and data C 263H before data B, An inter-line signal processing circuit for performing line conversion using a signal within a field, an inter-field signal processing circuit for performing line conversion using a signal between fields, and a comparison circuit for comparing the levels of data A, B and C, A boundary signal processing circuit that performs signal processing to smoothly connect the output of the inter-line signal processing circuit and the output of the inter-field signal processing circuit at the boundary portion between the moving image and the still image, using the output of the comparison circuit as a control signal, A switching circuit for switching and outputting the output of the inter-field signal processing circuit and the output of the boundary signal processing circuit according to the output of the comparison circuit; Claim the output signal after converting the output of the switching circuit 1
Field conversion circuit described in. 3. The boundary signal processing circuit receives an arbitrary data B in a field to be subjected to field conversion and data A 1H before the data B as input, and odd and even field numbers of reproduced signals and output signals. For a first switching circuit that outputs two outputs X and Y, and two input data Y and Z, D1 = Y + k. (Y-
Z) for the first arithmetic circuit, and for three input data X, Y, Z, D3 = (X + Y)
A second arithmetic circuit that calculates / 2 + k · (X−Z), a second switching circuit that receives the outputs of the first and second arithmetic circuits as input, and switches between X and Y in magnitude relation; A first comparison circuit that outputs the smaller of the input data, a second comparison circuit that outputs the larger of the two input data, and a signal that indicates the magnitude relationship of the three input data. And a third comparison circuit for outputting X, Y, and
A third switching circuit that switches according to the output signal of the third comparison circuit indicating the magnitude relationship of Z, and the first switching circuit is configured so that the odd number and the even number of the field numbers of the reproduction signal and the output signal match. If they do not match, X = data A and Y = data B are output, and if they do not match, X is output.
= Data B, Y = data A is switched to output, Z = data C is operated by the first and second operation circuits, and the first and second operation results D1 and D3 are switched by the second operation. The second switching circuit outputs the first calculation result D1 to the first comparison circuit and the second calculation result D3 to the second comparison circuit when X> Y. X <Y
In the case of, the second operation result D3 is given to the first comparison circuit,
The first operation result D1 is switched so as to be output to the second comparison circuit. In the first and second comparison circuits, the output of the line-to-line signal processing and the first operation result D are performed.
The first and second operation results D3 are compared, the smaller data is output from the first comparison circuit, and the larger data is output from the second comparison circuit, and is input to the third switching circuit. The third switching circuit, when X>Y> Z, or Y
>X> Z, the output of the first comparison circuit is set to Z>X> Y.
2. The field conversion circuit according to claim 1, wherein the field conversion circuit is configured to select and output the output of the second comparison circuit in the case of, or in the case of Z>Y> X. 4. A jump detection circuit for detecting a field jump of the input video signal, and motion information of the first and second motion adaptive Y / C separation circuits is controlled based on a detection signal of the jump detection circuit. Means for detecting the field jump, the first or second
2. The Y / C separation signal processing using the signal in the field is forcibly carried out when the motion adaptive Y / C separation circuit of FIG. 7 cannot perform the Y / C separation processing by the frame comb filter. Field conversion circuit described in.