WO2005091648A1

WO2005091648A1 - Motion-adaptive 3d y/c separation system and image improving method

Info

Publication number: WO2005091648A1
Application number: PCT/JP2005/004027
Authority: WO
Inventors: Masaya Kobayashi
Original assignee: Sony Corporation
Priority date: 2004-03-23
Filing date: 2005-03-02
Publication date: 2005-09-29
Also published as: JP2005277562A

Abstract

A motion-adaptive 3D Y/C separation system includes: 2D Y/C separation means for performing Y/C separation for a moving picture for a composite video signal inputted; 3D Y/C separation means for performing Y/C separation for a still image for the composite video signal; motion detection means for detecting a video motion from the composite video signal; selection means (mixer 7) for selecting a luminance signal and a color signal corresponding to the detection result of the motion detection means, by using the processing result of the 2D Y/C separation means and the 3D Y/C separation means; and correction differentiation means for subjecting the luminance signal isolated by the 2D Y/C separation means to image correction and limiting the image correction for the luminance signal isolated by the 3D Y/C separation means. It is possible to suppress image deterioration caused by switching between a moving picture and a still image when separating the luminance signal and the color signal from the composite video signal by the motion-adaptive 3D Y/C separation.

Description

Specification

Motion adaptive 3D YZC separation system and image quality improvement method

The present invention relates to a system and method for suppressing deterioration of image quality when a luminance signal and a chrominance signal are separated from a composite video signal by a motion adaptive 3D YZC separation process. Background technology ''

A motion-adaptive 3D Y / C separation circuit exists as a circuit for separating the luminance signal and the chrominance signal from the composite video signal. The motion-adaptive 3D Y / C separation circuit performs 2D YZC separation (field 內 YZC separation) for moving images from the input composite video signal, and 3D Y / C separation for still images ( In addition to separating the luminance signal and the chrominance signal by processing, the motion of the video is detected from the input composite video signal and the luminance signal adapted to the motion detection result. And two-dimensional Y / C separation processing for color signals and a circuit for selecting using the result of the three-dimensional Y / C separation processing (for example, Japanese Patent Application Laid-Open No. (see paragraph numbers 0000-2 to 010, FIG. 4).

Also, video equipment equipped with a motion-adaptive 3D Y / C separation circuit (for example, a video display device or video recording device to which a composite video signal is input, such as a television receiver or DVD recorder) It is widely practiced to apply image quality correction processing such as contour correction to luminance signals separated by a motion-adaptive 3D Y / C separation circuit.

Figure 1 is a block diagram showing an example of the configuration of a conventional motion-adaptive 3D YZC separation system (a system in which a contour correction circuit is provided after the motion-adaptive 3D Y / C separation circuit). A / D converter not shown The composite video signal, which has been digitally converted by the converter, is converted into a two-dimensional Y / C separation circuit 101 in the motion-adaptive three-dimensional Y / C separation circuit 100, a three-dimensional Y / C separation circuit 102, and a motion detection circuit. Input to 103 and frame memory 104.

The two-dimensional Y / C separation circuit 101 performs YZc separation processing for moving images using a line-com filter or band-pass filter on the input composite video signal (Y / c separation processing in the field) The circuit that performs The luminance signal Y 2 D separated by the two-dimensional Y / C separation circuit 101 is input to the mixer 105. The color signal C 2 D separated by the two-dimensional Y / C separation circuit 101 is input to the mixer 106.

As the frame memory 104, a motion-adaptive 3D Ύ / C separation circuit for NTSC composite video signals uses a memory that delays the input signal by one frame, and a PAL In the motion adaptive 3D Y / C separation circuit for positive video signals, a memo V that delays the input signal by 2 frames is used. The composite video signal delayed by the frame memory 104 is three-dimensional.

It is sent to the Y / C separation circuit 102 and the motion detection circuit 103.

The three-dimensional Y / C separation circuit 102 is a circuit that performs YZC separation processing (Y / C separation processing between frames) for still images on the input composite video signal using a framecom filter. The luminance signal Y 3 D separated by the three-dimensional YZC separation circuit 102 is input to the mixer 105. The color signal C 3 D separated by the three-dimensional YZC separation circuit 102 is input to the mixer 106.

The motion detection circuit 103 applies a filter to both the input composite video signal and the composite video signal from the frame memory 104, generates temporary luminance signals and color signals, and calculates the difference between them. Video motion based on the detected motion This is a circuit that outputs as a coefficient (a coefficient whose value is '11 1 1, 'when the motion is maximum, and which is' 0 0 0 0' when it is stationary). This motion coefficient is sent as a control signal to mixers 105 and 106, respectively.

In the mixer 105, the mixing ratio of the luminance signal Y2D and the luminance signal Y3D is determined according to the value of the motion coefficient (the ratio of the luminance signal Y2D increases as the value of the motion coefficient increases). Is higher). In the mixer 106 as well, the mixture ratio of the color signal C 2 D and the color signal C 3 D is similarly selected according to the value of the motion coefficient.

The motion-adaptive three-dimensional YZC separation circuit 100 outputs a luminance signal mixed by the mixer 105 and a color signal mixed by the mixer 106. Of these, the dancer signal from the mixer 105 is sequentially input to the subsequent vertical contour correction circuit 107 and horizontal contour correction circuit 108 to perform vertical and horizontal contour correction processing. Is done.

By the way, in the conventional motion-adaptive 3D YZC separation circuit as shown in Fig. 1, depending on the content of the displayed video, it changes from a stationary state to a moving state (or conversely, from a moving state to a stationary state). The video may look unnatural when transitioning. The reasons are as follows.

The line comb filter used in the two-dimensional Y / C separation circuit for moving images uses the phase relationship of the color subcarriers and the vertical correlation of the color signals (the color signal waveforms are approximated between adjacent horizontal lines). Is used to separate the color signals. That is, in the composite video signal of the NTSC system, as shown in Fig. 2 (a), the phase of the chrominance subcarrier is shifted by 180 ° in one horizontal line, so that there is no vertical correlation in the chrominance signal. The color signals can be separated: ^ by taking the difference between the matching horizontal lines.

Fig. 1 (b) shows a PAL composite video signal. As shown in the figure, the phase of the color subcarrier is shifted 180 ° between the two horizontal lines, so if there is a vertical correlation between the color signals, the color is obtained by taking the difference between the horizontal lines separated by two horizontal lines. Signals can be separated.However, when the color signals are directly correlated, for example, in an image containing horizontal or diagonal lines, the difference between these horizontal lines can be calculated. As a result, the chrominance signal component leaks into the luminance signal component, thereby deteriorating the signal band.

Here, if the color signals are separated by a horizontal band-pass filter that passes the carrier frequency of the color subcarrier instead of the line-com filter, degradation of the band in the image containing lines can be prevented. can do. However, even with such a horizontal non-pass filter, it is not possible to determine the diagonal component of the luminance signal, so that in the case of an image containing diagonal lines, the luminance signal component is also the color signal component. O The area will deteriorate due to leakage

In this way, the two-dimensional Y / C separation processing for moving images may cause band degradation, while the three-dimensional Y / C separation processing for still images may cause band deterioration. Invitation <YZC separation can be performed o

Therefore, when the video transitions from a moving state to a stationary state (or conversely, from a stationary state to a moving state), the output signal from the two-dimensional Y / C separation circuit and the three-dimensional Υ / The output signal from the C separation circuit is switched. (In the example of Fig. 2, both outputs from the mixer are

-f ± f- The mixing ratio of the input signal greatly changes) .Therefore, a difference in resolution occurs when displaying the image, and the image looks unnatural.

In particular, when a line comb filter is used in the two-dimensional Y / C separation circuit, the PAL method separates two horizontal lines as shown in Fig. 2 (b). Since the difference in the video data is used, the degree of bandwidth degradation is greater than in the NTSC system.o In recent years, with the price reduction of frame memory and line memory, consumer video equipment has become Also

Motion adaptive 3D Υ / for PAL composite signals. Since a separation circuit is often installed, the problem of image quality deterioration when switching between such a moving image and a still image becomes prominent.

In the motion-adaptive 3D Y / C separation circuit system shown in Fig. 1, the luminance signal separated by the motion-adaptive 3D YZC separation circuit is contour-corrected by a vertical contour correction circuit and a horizontal contour correction circuit. Ο However, contour correction is performed uniformly on both the luminance signal from the two-dimensional Y / C separation circuit and the luminance signal from the three-dimensional Y / C separation circuit. The problem of image quality degradation when switching between video and still images is not solved o

In view of the above points, the present invention provides a method of deteriorating image quality when switching between a moving image and a still image when a luminance signal and a color signal are separated from a composite video signal by motion adaptive 3D Y / C separation processing. Ο Disclosure of the invention

In order to solve this problem, a motion-adaptive three-dimensional Υ / C separation system according to the present invention includes two-dimensional Y / C separation means for separating a luminance signal and a chrominance signal from an input composite video signal; (G) three-dimensional Υ / C separation means for separating a luminance signal and a chrominance signal from a video signal, motion detection means for detecting video motion from the composite video signal ', and adaptation to the detection result of the motion detection means Selecting means for selecting a luminance signal and a color signal using the processing results of the two-dimensional Y / C separating means and the three-dimensional YZC separating means; and a luminance signal separated by the two-dimensional Y / C separating means. Image quality correction And a correction differentiating means for limiting the image quality correction processing for the luminance signal separated by the three-dimensional Y / C separating means.

In this motion-adaptive 3D Y / C separation system, as in a normal motion-adaptive 3D Y / C separation circuit, a 2D YZC separation process for moving images from an input composite video signal and a still image The three-dimensional Y / C separation process separates the luminance signal and the chrominance signal, and detects the motion of the video from the input composite video signal. Are selected using the results of 2D Y / C separation processing and 3D Y / C separation processing.

However, in this motion-adaptive cubic 7Ώ YC separation system, the luminance signal separated by the secondary Y / C separation unit by the correction differentiation unit is subjected to image quality correction processing. For the bright signal separated by the separating means, the image quality correction processing of is limited.

By differentiating the image quality correction processing between the luminance signal separated by the two-dimensional Y / C separation processing and the luminance ifc separated by the three-dimensional YC separation processing, the color signal Can compensate for the degradation of the band in the 2D YZC separation process when the vertical correlation of the image is lost, and reduce the difference in the sense of resolution when switching between video and still images. Can be improved.

In the motion-adaptive three-dimensional YZC separation system, as an example, it is preferable that the correction differentiator is configured by an image quality correction circuit to which only the luminance signal separated by the two-dimensional YZC separator is supplied. is there. As a result, the existing motion-adaptive 3D Y /

With a small change to the C separation system, the difference in the sense of resolution when switching between moving images and still images can be reduced. Alternatively, in this motion-adaptive three-dimensional YZC separation system, the selection means is used to select the output signal of the two-dimensional Y_C separation means and the output signal of the three-dimensional Y / C separation means according to the detection result of the motion detection means. And a correction differentiating means for supplying the luminance signal mixed by the mixing circuit and the magnitude of the motion detected by the motion detecting means. It is also preferable to configure an image quality correction circuit that lowers the correction level of the image quality correction processing in accordance with the decrease in the image quality. In that case, too, with a slight change to the existing motion-adaptive 3D Y / C separation system as shown in Fig. 1, the sense of resolution when switching between video and still images can be obtained. The difference between the two can be reduced.

In this motion-adaptive three-dimensional Y / C separation system, as an example, the capture differentiating means may perform vertical contour correction processing and Z or horizontal contour correction processing as image quality correction processing. It is preferable to configure as follows. As a result, the vertical and horizontal edge portions of the luminance signal separated by the two-dimensional Y / C separation process are different from the vertical and horizontal edge portions of the luminance signal separated by the three-dimensional Y / C separation process. Is emphasized, so that the difference in the sense of resolution when switching between a moving image and a still image can be further eliminated.

Next, the image quality improving method according to the present invention comprises a two-dimensional Y / C separation means for separating a luminance signal and a color signal from an input composite video signal, and a luminance signal and a color signal from the composite video signal. Three-dimensional Y / C separation means for separating the image, a motion detection means for detecting the motion of the video from the composite video signal, and a luminance signal and a color signal adapted to the detection result of the motion detection means. The motion-adaptive three-dimensional Y / C separation circuit having the two-dimensional Y / C separation means and the selection means for selecting using the processing results of the three-dimensional YZC separation means performs processing for improving image quality. In the method of applying, this 2D YZ C separation means It is characterized in that image quality correction processing is performed on the luminance signal separated by, and the image quality correction processing is restricted on the luminance signal separated by the three-dimensional Y / C separation means.

According to this image quality improvement method, the luminance signal separated by the two-dimensional Y / C separation means in the motion-adaptive three-dimensional Y / C separation circuit is subjected to image quality correction processing. This image quality correction processing is restricted for the luminance signal separated by the three-dimensional Y / C separation means in the Y / C separation circuit.

In this way, by differentiating the image correction processing between the luminance signal separated by the two-dimensional Y / C separation processing and the luminance signal separated by the three-dimensional YZC separation processing, the vertical It is possible to compensate for the deterioration of the band in the 2D Y / C separation processing when the correlation is lost, and to reduce the difference in the sense of resolution when switching between video and still images. Can be improved. Brief Description of Drawings

Figure 1 is a block diagram showing a configuration example of a conventional motion-adaptive 3D Y / c separation system.

,,

FIG. 2 is a diagram showing the phase relationship of the mouth maker of the composite video signal.

FIG. 3 is a block diagram showing a configuration example of a motion adaptive 3D Y / C separation system using the present invention.

FIG. 4 is a block diagram illustrating a configuration example of the two-dimensional Ύ / C separation circuit in FIG.

Fig. 5 is a block diagram showing a configuration example of the 3D Y / C separation circuit in Fig. 3.

FIG. 6 is a block diagram showing a configuration example of the vertical contour correction circuit of FIG. FIG. 7 is a block diagram showing a configuration example of the horizontal contour correction circuit of FIG.

FIG. 8 is a block diagram showing another configuration example of the motion adaptive 3D Y / C separation system to which the present invention is applied.

FIG. 9 is a block diagram showing a configuration example of the vertical contour correction circuit of FIG.

FIG. 10 is a block diagram showing a configuration example of the horizontal contour correction circuit of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an example in which the present invention is applied to separate a luminance signal and a chrominance signal from a PAL composite video signal will be specifically described with reference to the drawings.

FIG. 3 is a block diagram showing a configuration example of a motion adaptive 3D Y / C separation system to which the present invention is applied. This motion-adaptive 3D Y / C separation system includes a 2D Y / C separation circuit 1, a 3D YZC separation circuit 2, a motion detection circuit 3, a frame memory 4, and a vertical contour correction circuit. 5, a horizontal contour correction circuit 6, a mixer 7, and a mixer 8.

A composite video signal digitally converted by an AZD converter (not shown) is input to a two-dimensional Y / C separation circuit 1, a three-dimensional Y / C separation circuit 2, a motion detection circuit 3, and a frame memory 4.

Frame memory 4 is a memory for delaying an input signal by two frames. The composite video signal delayed by the frame memory 4 is sent to a three-dimensional Y / C separation circuit 2 and a motion detection circuit 3.

The two-dimensional Y / C separation circuit 1 is a circuit that performs YZc separation processing for moving images (YZc separation processing in a field) on an input composite video signal. Figure 4 shows a configuration example of this two-dimensional Y / C separation circuit 1. Indicates. The input composite video signal (represented as signal S0 in Figure 4) is delayed by two horizontal lines in line memory 11 and then further delayed by two horizontal lines in line memory 12. You. Then, the signal SO, the output signal SI of the line memory 11 (composite video signal two horizontal lines away from the input composite video signal), and the output signal S 2 of the line memory 12 (input composite video signal (Composite video signal four horizontal lines away from the composite video signal), the BPF (band pass filter) 13, 14, and 15 remove the frequency components of the color subcarrier other than near the carrier frequency.

The output signal of BPF 13 is input to subtractor 16. The output signal of BPF 14 is input to subtractor 16, subtracter 18 and BPF 22. The output signal of BPF 15 is input to subtracter 18. The subtractor 16 subtracts the output signal of the BPF 13 (the component near the carrier frequency of the signal SO) from the output signal of the BPF 14 (the component near the carrier frequency of the signal S 1). . The output signal of the subtracter 16 is adjusted to half the gain by the gain controller 17 so that the color signal (the input composite video signal S0 and the output signal S1 of the line memory 11) is output. “Upper two line color signal”) is required.

In the subtracter 18, the output signal of BPF 15 (the component near the carrier frequency of the signal S 2) is subtracted from the output signal of BPF 14. Then, the output signal of the subtracter 16 is adjusted to half the gain by the gain controller 17 so that the color signal (the output signal S 1 of the line memory 11 and the output signal of the line memory 12) is obtained. The “lower two-line color signal” from signal S2 is required.

The output signal of the gain controller 17 and the output signal of the gain controller 19 are added by the adder 20. Then, the output signal of the adder 20 is adjusted to half the gain by the gain controller 21. As a result, a color signal (“3 line color signal” from input composite video signal S 0, output signal S 1 of line memory 11 and output signal S 2 of line memory 12) is obtained. Can be

The BPF 22 removes the frequency components other than the carrier frequency of the chrominance subcarrier from the output signal of the BPF 14 (the high-frequency component of the signal S1). Filter by "B

PS color signal ”) is required.

These four color signals output from the gain controller 17, the gain controller 19, the gain controller 21, and the BPF 22 force can be switched by a 4-input / 1-output switch. Entered in 2 3. The output signal of the gain controller 21 is supplied to the vertical contour detection circuit 5 (see FIG.

3, 6) are also sent as the vertical contour emphasis signal AP.

The output signals of BPF 13, BPF 14 and BPF 15 are also input to the chroma correlation detector 24. The chroma correlation detection unit 24 detects the vertical correlation of the color signals, and in accordance with the detection result, causes the switching switch 23 to select one of the four types of color signals described above. Circuit o

The output signal of BPF 13 and the BPF

The output signal of 14 is added by the adder 25. And the adder

The output signal of 25 is converted into an absolute value by an absolute value circuit 26, smoothed by an LPF (open-path filter) 27, and then input to a comparison circuit 31 and a comparison circuit 32.

Further, the output signal of BPF 14 and the output signal of BPF 15 are added by adder 28. Then, the output signal of the addition 28 is converted into an absolute value by the absolute value circuit 29, smoothed by the LPF 30, and then input to the comparison circuit 32 and the comparison circuit 33.

The comparison circuit 31 compares the level A of the input signal from the LP

Compare the level B of the input signal from F30 with the vertical phase of the color signal Seki is determined. In this determination method, for example, C = BZ (A + B) is calculated, and when 1/2, A and B are almost equal, so that 3 lines (input composite video signal SO, line memory 1 1 It is determined that all of the output signals S 1 of the line memory 12 and the output signal S 2 of the line memory 12 have a vertical correlation of the color signals. On the other hand, in the case of C 1, the upper two lines (input composite G), it is determined that only the video signal S 0 and the output signal S 1) of the line memory 11 have a vertical correlation of the color signals. 2 line (line note) 1 1 output signal S 1 and line memory 1

There is a method of determining that only the output signal S 2) of FIG.

Then, the comparison circuit 31 sends a signal for controlling the selection by the switching switch 23 to the switching control section 35 in accordance with the result of this determination.

The comparison circuit 32 compares the level A of the input signal from the LPF 27 with a predetermined reference level R ef, and sends a signal indicating the comparison result to the switching circuit 34.

The comparison circuit 33 compares the level B of the input signal from the LPF 30 with the reference level R ef, and switches the signal indicating the comparison result to the switching circuit.

Send to 3-4.

Based on the comparison results of the comparison circuit 32 and the comparison circuit 33, the switching circuit 34 is used when both the level A and the level B are lower than the reference level Ref (that is, when the luminance signal is near the carrier frequency). If the high-frequency component is not included), a command to select the BPF color signal ignoring the control signal from the comparison circuit 31 is sent to the switching control section 35. On the other hand, if at least one of the level A or the level B is equal to or higher than the reference level Ref, a command for transferring the control signal from the comparison circuit 31 to the switching switch 23 as it is is Switching control unit 3

Send to 5. The switching control unit 35 sends either a control signal for selecting a BPF color signal or a control signal from the comparison circuit 31 to the switching switch 23 according to the command from the switching circuit 34.

The switching switch 23 selects one of the four types of input color signals according to the control signal from the switching control section 35. The color signal selected by the switch 23 is output from the two-dimensional separation circuit 1 as a color signal C 2 D separated from the input composite video signal, and is also output by a subtractor 36. Is subtracted from the output signal S 1 of the line memory 11. The output signal of the subtractor 36 is output from the two-dimensional separation circuit 1 as a luminance signal Y 2 D separated from the input composite video signal. As shown in FIG. 3, the luminance signal Y 2 D separated by the two-dimensional separation circuit 1 is input to the vertical contour correction circuit 5. The color signals C 2 D separated by the two-dimensional separation circuit 1 are input to the mixer 8.

The three-dimensional Y / C separation circuit 2 is a circuit that performs Y / C separation processing for still images (Y / C separation processing between frames) using a framecom filter. FIG. 5 shows a configuration example of the three-dimensional Y / C separation circuit 2. The input composite video signal is delayed by two horizontal lines in the line memory 42 to adjust the delay with the luminance signal Y 2 D and the color signal C 2 D from the two-dimensional YZC separation circuit 1 (Fig. 4), and is input to the subtractor 4 3. The composite video signal from the frame memory 4 in FIG. 3 is also input to the subtracter 43 after the same delay adjustment is performed in the line memory 42. The subtractor 43 subtracts the output signal of the line memory 41 from the output signal of the line memory 42. Then, the output signal of the subtractor 43 is adjusted by a gain controller 44 so that the gain is halved, whereby the color signal C 3D is separated. The color signal C 3 D is subtracted from the output signal of the line memory 42 by the subtractor 45. Separates the luminance signal Y3D. As shown in FIG. 3, the luminance signal Y 3 D separated by the three-dimensional separation circuit 2 is input to the mixer 7. The color signals C 3 D separated by the three-dimensional separation circuit 1 are input to the mixer 8.

The motion detection circuit 3 is a circuit that detects video motion based on the difference between the input composite video signal and the composite video signal from the frame memory 4, and uses the existing motion-adaptive 3D YZC separation. It has the same configuration as the motion detection circuit provided in the circuit. The motion detection circuit 3 outputs the detection result as a 4-bit motion coefficient (the value is' 1 1 1 1 'when the motion is maximum, and the value is S' 0 0 0 0, Is output. The motion coefficients are sent to mixers 7 and 8 as control signals.

The vertical contour correction circuit 5 is a circuit that performs a vertical contour correction process on the luminance signal. FIG. 6 shows a configuration example of the vertical contour correction circuit 5. The vertical contour emphasis signal AP (the output signal of the gain controller 21 in FIG. 4) from the two-dimensional separation circuit 1 is limited in the horizontal band by the LPF 51, and is cored by the limiter 52. Processing (processing to remove parts where the absolute value of the amplitude level is less than a certain value to prevent emphasis on minute noise components) and Limiter processing (processing to limit the upper limit of the absolute value of the amplitude level) After that, the gain is adjusted by the gain controller 53.

Then, the output signal of the gain controller 53 is added to the luminance signal Y 2 D from the two-dimensional separation circuit 1 by the adder 55, so that the vertical edge portion of the luminance signal Y 2 D Be emphasized. As shown in FIG. 3, the luminance signal subjected to the vertical contour correction processing in the vertical contour correction circuit 5 is input to the horizontal contour correction circuit 6.

The horizontal contour correction circuit 6 is a circuit that performs a horizontal contour correction process on the luminance signal. FIG. 7 shows a configuration example of the horizontal contour correction circuit 6. High-frequency components in the horizontal direction are extracted from the input luminance signal by HPF (high-pass filter) 61. The high-frequency component in the horizontal direction can be extracted by using a BPF instead of the HPF.

The output signal of the HPF 61 is subjected to coring processing and limiter processing by the limiter 62, and then the gain is adjusted by the gain controller 63. The adder 64 adds the output signal of the gain control port 63 to the input luminance signal, so that the horizontal edge portion of the input luminance signal is emphasized. As shown in FIG. 3, the luminance signal subjected to the horizontal contour correction processing by the horizontal contour correction circuit 6 is input to the mixer 7.

In the mixer 7, the mixing ratio between the luminance signal from the horizontal contour correction circuit 6 and the luminance signal Y3D from the three-dimensional separation circuit 2 is determined according to the value of the motion coefficient (the value of the motion coefficient is' 1 1 1 When the value is 1 ', only the luminance signal from the horizontal contour correction circuit 6 becomes available, and as the value of the motion coefficient decreases, the proportion of the luminance signal Y3D increases, and the value of the motion coefficient becomes Is selected so that only the luminance signal Y3D is present). In the mixer 8 as well, the mixing ratio between the color signal C 2 D from the two-dimensional separation circuit 1 and the color signal C 3 D from the three-dimensional separation circuit 2 is similarly selected according to the value of the motion coefficient.

From the motion-adaptive three-dimensional YZC separation system in FIG. 3, a luminance signal mixed by the mixer 7 and a color signal mixed by the mixer 8 are output to the outside.

According to the motion-adaptive three-dimensional YZC separation system configured as described above, the luminance signal Y 2 D separated by the two-dimensional separation circuit 1 and the luminance signal Y 3 D separated by the three-dimensional separation circuit 2 Only the luminance signal Y 2 D is supplied to the vertical contour correction circuit 5 and the horizontal contour correction circuit 6 to perform vertical and horizontal contour correction processing.

Thus, the luminance signals Y 2 D and 3 By differentiating the contour correction processing for the luminance signal Y 3 D by the dimension Y / C separation processing (here, no contour correction processing is performed for the luminance signal Y 3 D), two-dimensional The vertical and horizontal edge portions of the luminance signal Y 2 D by the YZC separation process are emphasized more than the vertical and horizontal edge portions of the luminance signal Y 3 D by the three-dimensional Y / C separation process.

As a result, when the vertical correlation of the color signals is impaired, the band is degraded in the two-dimensional YZC separation processing (particularly, as in the case of an image including oblique lines, the BPF 22 in FIG. (Degradation of band that occurs even if color signals are separated) Compensation can be performed to eliminate the difference in resolution when switching between moving images and still images, thus improving image quality. Can be done.

Also, slight changes are made to the existing motion-adaptive 3D Y / C separation system shown in Fig. 1 (here, a mixer that mixes luminance signals, a vertical contour correction circuit and a horizontal contour correction circuit). By simply switching the arrangement between the two, it is possible to eliminate the difference in the sense of resolution when switching between moving images and still images.

Next, FIG. 8 is a block diagram showing another configuration example of the motion adaptive 3D Y / C separation system to which the present invention is applied. Of the motion-adaptive 3D Y / C separation system, those parts common to the motion-adaptive 3D Y / C separation system shown in Fig. 3 are denoted by the same reference numerals as in Fig. 3. This motion-adaptive 3D Y / C separation system includes a 2D Y / C separation circuit 1, a 3D YZC separation circuit 2, a motion detection circuit 3, a frame memory 4, a mixer 7, It comprises a mixer 8, a vertical contour correction circuit 9, and a horizontal contour correction circuit 10.

A composite video signal digitally converted by an AZD converter (not shown) is input to a two-dimensional Y / C separation circuit 1, a three-dimensional YZC separation circuit 2, a motion detection circuit 3, and a frame memory 4. Frame memory 4 is a memory for delaying an input signal by two frames. The composite video signal delayed by the frame memory 4 is sent to the three-dimensional Y / C separation circuit 2 and the motion detection circuit 3.

The two-dimensional YZC separation circuit 1 is a circuit that performs Y / C separation processing (field 內 YZC separation processing) for a moving image on an input composite video signal, and has a configuration as shown in FIG. The luminance signal Y 2 D separated by the two-dimensional separation circuit 1 is input to the mixer 7. The color signals C 2 D separated by the two-dimensional separation circuit 1 are

Entered in 8.

The three-dimensional Y / C separation circuit 2 is a circuit that performs Y / C separation processing for still images (Y / c separation processing between frames) using a frame-commutator, as shown in FIG. Make up the structure. The luminance signal Y 3 D separated by the three-dimensional separation circuit 2 is input to the mixer 17. The color signals C 3 D separated by the three-dimensional separation circuit 1 are input to the mixer 8.

The motion detection circuit 3 detects the motion of the image based on the difference between the input composite video signal and the composite video signal of the frame memory 4 and the like, and uses the detection result as a 4-bit motion coefficient ( The value is '1 1 1 1' when the movement is maximum, and the value is

'0 0 0 0'). This motion coefficient is sent as a control signal to each of the mixer 7, the mixer 8, the vertical contour correction circuit 9, and the horizontal contour correction circuit 10.

In the mixer 7, the mixing ratio of the luminance signal from the horizontal contour correction circuit 6 and the luminance signal Y3D from the three-dimensional separation circuit 2 is determined according to the value of the motion coefficient (the value of the motion coefficient is' 1 1 When 1 1 ′, only the luminance signal from the horizontal contour correction circuit 6 is provided. As the value of the motion coefficient decreases, the ratio of the luminance signal Y 3 D increases, and the value of the motion coefficient becomes 0 0 0

It is selected so that only the luminance signal Y3D is obtained at 0 and. Miki In the circuit 8, the mixing ratio of the color signal C 2 D from the two-dimensional separation circuit 1 and the color signal C 3 D from the three-dimensional separation circuit 2 is similarly selected according to the value of the motion coefficient. .

The luminance signal mixed by the mixer 7 is input to the vertical contour correction circuit 9. The vertical contour correction circuit 9 is a circuit that performs a vertical contour correction process on the luminance signal. FIG. 9 shows an example of the configuration of the vertical contour correction circuit 9, and portions common to the vertical contour correction circuit 5 shown in FIG. 6 are denoted by the same reference numerals. The vertical contour emphasis signal AP (the output signal of the gain controller 21 in Fig. 4) from the two-dimensional separation circuit 1 is limited in the horizontal band by the LPF 51, and is cored by the limiter 52. After the limiter processing, the gain is adjusted by the gain controller 53.

The output signal of the gain controller 53 is added to the multiplier 56 by a coefficient X obtained by shifting down the motion coefficient from the motion detection circuit 3 by 4 bits (the value becomes 1 when the motion is maximum. When stationary, a coefficient whose value is 0) is multiplied.

Then, the output signal of the multiplier 56 is added to the luminance signal from the mixer 7 by the adder 55, whereby the vertical edge portion of the luminance signal is emphasized. As shown in FIG. 8, the luminance signal that has been subjected to the vertical contour correction processing by the vertical contour correction circuit 9 is input to the horizontal contour correction circuit 10.

The horizontal contour correction circuit 10 is a circuit that performs a horizontal contour correction process on a luminance signal. FIG. 10 shows an example of the configuration of the horizontal contour correction circuit 6, and the same reference numerals are given to portions common to the horizontal contour correction circuit 6 shown in FIG. From the input luminance signal, a high frequency component in the horizontal direction is extracted by the HPF 61. The output signal of HPF 61 is subjected to core ring processing and limiter processing by limiter 62, and then the gain is adjusted by gain controller 63. The output signal of the gain controller 63 is multiplied by the multiplier 65 by the same coefficient X as that of the multiplier 56 in the vertical contour correction circuit 9. Then, the output signal of the multiplier 65 is added to the input luminance signal by the adder 64, so that the horizontal edge portion of the input luminance signal is strongly reduced.

The luminance signal output from the horizontal contour correction circuit 10 and the color signal mixed by the mixer 8 are output to the outside in the motion adaptive 3D YZC separation system shown in FIG.

According to the motion-adaptive three-dimensional YZC separation system configured as described above, the luminance signal Y 2 D separated by the two-dimensional separation circuit 1 and the luminance signal Y 3 D separated by the three-dimensional separation circuit 2 ,, mixed with Kisa 7 dripping! ^ Provided to the contour correction circuit 9 and the horizontal contour correction circuit 10, but detected by the motion detector 3 and the positive level detector of the contour correction processing by the vertical contour correction circuit 9 and the horizontal contour correction circuit 10. (The coefficient of motion is' 0 when stationary.

Since the coefficient X of the multiplier 56 in the vertical contour correction circuit 9 and the multiplier 65 in the horizontal contour correction circuit 10 becomes 0, the positive level force is obtained. S becomes zero).

In this way, by differentiating the contour correction processing between the luminance signal Y 2 D by the two-dimensional Y / C separation processing and the luminance signal YD 3 by the three-dimensional Y / C separation processing, the two-dimensional The vertical and horizontal edge portions of the luminance signal Y 2 D obtained by the YZC separation process are emphasized more than the vertical and horizontal edge portions of the luminance signal Y 3 D obtained by the three-dimensional Y / C separation process.

As a result, when the vertical correlation of the color signals is impaired (particularly in the case of images containing oblique lines), the deterioration of the band in the two-dimensional Y / C separation processing is compensated for, and video and still images can be compensated. Since the difference in the sense of resolution at the time of switching can be eliminated, the image quality can be improved.

In addition, the existing motion-adaptive 3D Y / C separation system shown in Fig. 1 Only a small change to the video (in this case, a multiplier is added to the vertical contour correction circuit and the horizontal contour correction circuit) to eliminate the difference in the sense of resolution when switching between video and still images. can do.

In the configuration example of the vertical contour correction circuit 9 and the horizontal contour correction circuit 10 shown in FIGS. 8 and 9, the output signal of the gain controller 63 is multiplied by a coefficient X corresponding to the motion coefficient. It has become. However, as another example, the gain itself to be adjusted by the gain controller 63 is changed by a motion coefficient (when the motion coefficient is' 0000, the gain is set to 0). It may be.

Also, the configuration of the two-dimensional YZC separation circuit 1 shown in FIG. 4 and the configuration of the three-dimensional Y / C separation circuit 2 shown in FIG. 5 are merely examples, and two-dimensional Y / C Of course, the present invention can be applied to a case where a C separation circuit or a three-dimensional Y / C separation circuit is used.

As a method for differentiating the contour correction processing between the luminance signal Y 2 D obtained by the two-dimensional YZC separation processing and the luminance signal Y 3 D obtained by the three-dimensional Y / C separation processing, each of the above examples is used. A method other than that shown (for example, when the luminance signal Y 2 D and the luminance signal Y 3 D are subjected to contour correction processing using separate contour correction circuits, and the correction level of the luminance signal Y 2 D is increased, May be used.

Further, in the above example, the deterioration of the band in the two-dimensional YZC separation processing is compensated by the vertical contour correction and the horizontal contour correction. However, the present invention is not limited to this, and the degradation of the band in the two-dimensional Y / C separation processing can be compensated only by the vertical contour correction, compensated only by the horizontal contour correction, and image quality other than the contour correction. Compensation may be performed by normal processing (for example, DRC: dynamic resolution conversion processing).

Further, in the above example, the present invention is applied to separate the luminance signal and the chrominance signal from the PAL composite video signal. However, the luminance signal and the chrominance signal are separated from the NTSC composite video signal. The present invention may be applied to separate a signal from a signal.

As described above, according to the present invention, when the luminance signal and the chrominance signal are separated from the composite video signal by the motion adaptive 3D YZC separation processing, the case where the vertical correlation of the chrominance signal is impaired is considered. Compensation for the degradation of the band in the 2D YZC separation processing can reduce the difference in the sense of resolution when switching between moving images and still images, so that image quality can be improved. The effect is obtained.

In addition, simply changing the existing motion-adaptive 3D Y / C separation system (combination of motion-adaptive 3D YZC separation circuit and image quality correction circuit) can be used when switching between video and still images. This also has the effect of reducing the difference in the sense of resolution. In addition, the vertical and horizontal edge portions of the luminance signal separated by the two-dimensional Y / C separation processing are different from the vertical and horizontal edge parts of the luminance signal separated by the three-dimensional Y / C separation processing. By emphasizing, it is also possible to obtain the effect that the difference in the sense of resolution at the time of switching between a moving image and a still image can be more effectively eliminated.

Claims

The scope of the claims

1. Second order Y / C separation means for separating the degree signal and the color signal from the input composite video signal,

3 three-dimensional Y / C separation means for separating a luminance signal and a chrominance signal from a self-video video signal;

A motion detecting means for detecting a motion of the video from the composite video signal strength;

Selecting means for selecting a luminance signal and a color signal adapted to the detection result of the motion detecting means using the processing results of the two-dimensional .Y / C separating means and the three-dimensional YZC separating means;

An image quality correction process is performed on the luminance signal separated by the two-dimensional Y / C separation unit, and a correction that limits the image quality correction process on the luminance signal separated by the three-dimensional Y / C separation unit A motion-adaptive three-dimensional YZC separation system characterized by having differentiating means.

2. The movement according to claim 1, wherein said correction and differentiation means comprises an image quality correction circuit to which only the luminance signal separated by said two-dimensional YZC separation means is supplied. Adaptive 3D YZC separation system.

3. The selecting means selects a mixing ratio between the output signal of the two-dimensional Y / C separating means and the output signal of the three-dimensional Y / C separating means based on the detection result of the motion detecting means. Consisting of a mixing circuit,

The correction and differentiation unit is configured to supply the luminance signal mixed by the mixing circuit and supply the luminance signal mixed by the mixing circuit, and in response to a decrease in the magnitude of the motion detected by the motion detection unit, perform the image quality correction processing. A motion-adaptive three-dimensional YZC separation system according to item 1, which is characterized by comprising a quality correction circuit for reducing slime.

4. The correction differentiating means performs a vertical contour correction process and / or a horizontal ring correction process as the image quality correction process. 3. The motion adaptive 3D YZC separation system according to claim 1.

5. Two-dimensional Y / C separation means for separating the luminance signal and the chrominance signal from the input composite video signal,

Three-dimensional YZC separating means for separating a luminance signal and a chrominance signal from the composite video signal;

Motion detection means for detecting video motion from the composite video signal;

m Selection of selecting a luminance signal and a color signal corresponding to the detection result of the detecting means using the processing results of the two-dimensional Y / C separating means and the three-dimensional Y / C separating means. Means and

In the method of performing processing for improving image quality on a motion adaptive 3D Y / C separation circuit having

The luminance signal separated by the two-dimensional Y / C separation means

Performs image quality correction processing on the signal, and limits the image quality correction processing on the luminance signal separated by the three-dimensional YZC separation means.

An image quality improvement method characterized by this.

6. The image quality improvement method according to claim 5, wherein the image quality correction processing is performed only on the luminance signal separated by the two-dimensional YZC separation unit.

7 • The selection method is a hand movement detection hand em.

刖 d according to the detection result of

A mixing circuit for selecting a mixing ratio between the output signal of the two-dimensional Y / C separating means and the output signal of the three-dimensional YZC separating means,

The image quality correction processing is performed on the luminance signal mixed by the mixing circuit, and the correction level of the image quality correction processing is adjusted according to a decrease in the magnitude of the motion detected by the motion detection means. 6. The image quality improving method according to claim 5, wherein the image quality is reduced.

8 • Description of image quality according to claim 5, characterized in that vertical contour correction processing and Z or horizontal contour correction processing are performed as the image quality correction processing. fZ

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