JPH0846929A - Encoding/decoding system/device for picture signal - Google Patents

Abstract

PURPOSE:To receive the picture of high quality by executing video-encoding obtained by combining motion compensation prediction encoding and orthogonal conversion encoding on a picture signal, transmitting and receiving the signal, executing the scanning conversion processing of motion compensation on the decoded picture signal, interlacing/ scanning and displaying the signal. CONSTITUTION:A motion vector detection part 2 extracts a motion vector MV matching the scanning conversion processing of motion compensation in a decoding part in accordance with picture information PI. Namely, the motion vectors V0, V1 and V2 are extracted in inter-frame encoding as shown in scanning line interpolation in the interlacing scanning of the picture signal. In the non-interlacing scanning of the picture signal, the motion vector shown in scanning line interpolation is extracted. VLC parts 7 and 14 execute a prescribed variable length encoding processing on a coefficient quantization signal series S5 and the motion vector MV, and generate an encoding picture data series S11 and an encoding motion vector series 512. Then, an encoding bit stream signal PCD is generated through the series S12, the encoding data series S13 and a buffer part 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal coding / decoding system and apparatus for highly efficiently coding and transmitting an image signal, and more particularly to a video combining motion compensation predictive coding and orthogonal transform coding. An image signal encoding / decoding system and apparatus suitable for receiving a high-quality image by performing scan conversion for motion compensation on a decoded image signal using an encoded motion vector.

[0002]

2. Description of the Related Art In the field of high-efficiency coding of image signals, various coding methods have been devised so far. this house,
The video coding method that combines motion-compensated predictive coding and orthogonal transform coding is a prediction error signal that is the difference signal between the predicted signal generated by motion-compensating the previous frame signal with the motion vector and the current frame signal. Then, by encoding a transform coefficient obtained by subjecting this prediction error signal to DCT transformation (discrete cosine transformation), encoding with high compression efficiency can be realized.
It is adopted for video coding of MPEG1 and MPEG2, which are international standards, and will be used in future digital broadcasting and CA.
Research and development targeting TVs and package media is underway. In digital broadcasting using this encoding method, a high-quality image equivalent to the original image can be received at a bit rate of about 20 mega. However, since most of the image signals are interlaced scans, there remains a problem that the image quality is deteriorated due to interlace interference such as line flicker and pairing.

On the other hand, as a technique for reducing interlace interference, there is known interlace-non-interlace conversion in which a signal of a scanning line which is skipped in interlace scanning is generated by interpolation processing and displayed as a signal of non-interlaced scanning. ing. However, in order to generate the compensation signal, it is necessary to perform motion-adaptive signal processing that changes the characteristics according to the movement of the image. However, since the motion information is detected by the interlaced scanning signal, there is a problem in that a missed detection or an erroneous detection occurs, resulting in image deterioration.

Therefore, even if the above-mentioned technique for reducing the interfering interference is applied to the decoded image of the digital broadcast, the effect of improving the image quality is small, and the feature of the high quality digital broadcast cannot be fully utilized. There is.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to encode / decode a video signal which can receive a high quality and high definition image with almost no interlace interference. To provide a method and device.

[0006]

In order to achieve the above object, in the present invention, a decoding unit employs motion-compensated scan conversion signal processing for interlaced to non-interlaced conversion. The motion detection required for this signal processing is performed based on the motion vector used in the motion compensation predictive coding.

In the motion compensation predictive coding of the coding unit, signal processing for extracting a motion vector of a form suitable for the scan conversion process of motion compensation, or the decoding unit performs motion compensation from the decoded motion vector. The signal processing that selects the motion vector of a form suitable for the scan conversion processing is adopted.

Further, adaptive processing is adopted in which the mixing ratio of the interpolation signal for motion compensation and the interpolation signal for moving image of the prior art is changed according to the magnitude of the absolute value of the inter-frame difference signal for motion compensation.

[0009]

The predictive coding for motion compensation and the scan conversion processing for motion compensation according to the present invention will be described with reference to the schematic operation diagrams of FIGS.

In FIG. 1, the video signal is interlaced scan,
It shows the movement when the movement is vertical.

In the interframe predictive coding shown in FIG. 1A, for example, a motion vector V (horizontal) in one frame period is applied to the signal sequence of the first field and the signal sequence of the second field of interlaced scanning. V _x , vertical V _y ) are extracted. It should be noted that the motion vector V is V _x = 2m, V _y = 2n (m =
0, ± 1, ± 2, ..., N = 0, ± 1, ± 2 ,. Then, the difference between the prediction signal generated by motion compensation with the motion vector V and the original signal is detected as a prediction error signal. For example, the motion vector V ₀
Then, the difference between the signals of the scanning lines a and 1, V ₁ and the scanning lines a and 2 and V ₂ is detected as the prediction error signal.

On the other hand, in the scan conversion process for motion compensation, a signal of a scan line (interpolated scan line indicated by a black circle in the figure) that is missing in the interlaced scan is generated based on the motion vector V. For example, the interpolation scan line a (a ′) of the first (2) field
Is (α + α ′) / 2 from the scanning lines α and α ′ of the second (1) field in the motion vector V ₀ , the scanning lines β and β ′ in V ₁ , and the scanning lines γ and γ ′ in V _2. From (γ + γ ′)
Generate a 1/2 interpolation signal. And with this interpolation signal,
Interlace to non-interlace conversion is realized.

[0013] Incidentally, V _x = 2m relative motion vector V in the predictive coding, V _y = a case without the constraints of 2n is, V _x = 2m of the motion vector V in the scan conversion process of the motion compensation , V _y = 2n are selected. Then, the above-described interpolation signal is generated based on this motion vector.

In the inter-field predictive coding shown in FIG. 1B, a motion vector in a 1-field period is extracted from the signal sequence of the first (2) field, and motion compensation is performed using this motion vector. The difference between the predicted signal and the signal of the second (1) field is detected as a prediction error signal.

In the scan conversion process for motion compensation, a motion vector V whose components satisfy the conditions of V _x = m and V _y = n is selected. Then, based on the selected motion vector, a signal of a scanning line (interpolation scanning line indicated by a black circle in the figure) that is missing in the interlaced scanning is generated. For example, the interpolation scanning line a (a ′) in the first (2) field is the motion vector VV.
₀ 'In the second (1) Field of the scan line alpha, V _1', the scan boundary line beta, with V ₂ 'in the scan line alpha, generates an interpolation signal.

As described above, in the present invention, by using the motion vector suitable for the scan conversion processing of the motion compensation, the interpolation signal close to the ideal can be generated. On the other hand, when there is no motion vector that satisfies the condition of the scan conversion process of motion compensation, an interpolation signal is generated by the same motion adaptive signal process as the conventional technique.

In the scan conversion processing for motion compensation, the accuracy of interpolation depends on the motion vector. Therefore, if the accuracy of the motion vector is poor, the image is expected to deteriorate. However, in the area where the component of the motion compensation inter-frame difference signal is large, this kind of image quality deterioration can be avoided by changing to the motion adaptive signal processing as in the prior art. Further, according to the present invention, it is possible to achieve high-quality scan conversion in which interlace interference is extremely small and resolution is high as compared with the prior art.

Some video signals include those of non-interlaced scanning. For example, a cinema image or a commercial film can be regarded as a non-interlaced scanning serial signal of 24 frames or 30 frames per second. In order to avoid a large area flicker, a signal of this value is converted into a signal of 60 frames per second and displayed in the processing of converting the number of frames.

The second is a schematic diagram of the motion-compensating predictive coding and the motion-compensating scan conversion of the present invention for a video signal of this kind of non-interlaced scanning.

In predictive coding, a motion vector V between frames is extracted, and the difference between the signal of the previous frame and the signal of the current frame, which have been motion-compensated with this motion vector, is detected as a prediction error signal. For example, the scanning lines a and 1 for the motion vector V ₀ , the scanning lines a and 2 for V ₁ , and the scanning lines a and 3 for V _2.
The difference between and is detected as a prediction error signal.

On the other hand, in the scan conversion process of motion compensation, the signals of the interpolated scan lines indicated by black circles in the figure are generated by the motion vectors shown in FIG.
In 0 conversion and cinema mode, 24 to 60 conversion is realized.
That is, in the standard mode, the interpolated scan line a is (α + α ′) / 2, V ₂ from the scan lines α and α ′ in the motion vector V _0.
At ( ₄ and β '), (β and β') / 2 are generated, and at V ₄ , scanning lines γ and γ'are generated (γ + γ ') / 2 interpolation signals. On the other hand, in the cinema mode, interpolation scanning line a is 'from (alpha + alpha' and the scanning lines in the motion vector V ₀ α α) / 2,
At V ₃ , an interpolation signal of (β + β ′) / 2 is generated from the scanning lines β and β ′. The interpolation scanning line a ′ is an interpolation signal of (γ + γ ′) / 2 from the scanning lines γ and γ ′ in the motion vector V ₀ and (α ′ + α ″) / 2 from the scanning lines α ′ and α ″ in V _4. To generate. Then, with these motion vectors suitable for the scan conversion processing of motion compensation, an interpolation signal close to ideal is generated.

When there is no suitable motion vector for performing the scan conversion process of this motion compensation, the interpolation signal is calculated by the signal of the preceding frame or the average value of the signals of the preceding and succeeding frames as in the conventional case. To generate.

Further, the scan conversion processing for motion compensation is performed on an area in which the component of the inter-frame difference signal for motion compensation is small. Then, the deterioration of the image quality due to the poor precision of the motion vector is avoided.

Therefore, according to the present invention, it is possible to achieve the scan conversion of the number of frames conversion having a higher resolution and less judder interference (interference that impairs the smoothness of motion) as compared with the prior art.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the overall block diagram shown in FIG. The present embodiment is suitable for performing coding by limiting the motion vector used in the motion compensation predictive coding of the coding unit to a form suitable for the scan conversion processing of motion compensation. In the present embodiment, a case of video coding in which motion compensation predictive coding between frames and orthogonal transform coding of DCT transform (discrete cosine transform) are combined will be described as an example.

In the encoding unit shown in FIG. 5A, the image signal VS
Is input to the preprocessing unit 1, digitized, and image information PI (information such as image format and encoding mode)
A predetermined image format conversion based on the above is performed to generate a coded image signal sequence S1. For example, MPEG
In video coding conforming to 1 and 2, S1 is a macroblock signal sequence composed of 6 blocks (4 luminance signal blocks and 2 color difference signal blocks, block size is 8 pixels × 8 lines). .

The coded image signal sequence S1 is in accordance with a predetermined coding mode, the intra-frame coded frame (abbreviated as I picture) is DCT transform coded, and the inter-frame coded frame (abbreviated as P picture) is motion compensated frame. Inter-prediction coding and DCT transform coding are performed. FIG. 4 is a schematic diagram of a coding mode for an image signal of interlaced scanning. In the independent coding of the even / odd fields shown in FIG.
A field signal and a second field signal respectively form a sequence of encoded frames and are encoded. Further, in the coding after the progressive scan conversion in FIG. 9B, the first field signal and the second field signal are combined to form a series of coded frames, and the coding is performed. On the other hand, in the inter-frame / inter-field adaptive predictive coding of FIG. 6C, a prediction error signal between the inter-frame and the inter-field is added to the encoded frame sequence including the signal of the first field and the signal of the second field. The smaller one is selected and encoded. In the following, the encoding operation will be described by taking the independent encoding of FIG.

The switches 4 and 11 are connected to the terminal a in the I-picture coding mode and to the terminal b in the P-picture coding mode to perform coding processing. That is, the switch 4 switches the encoded image signal sequence S of the original image when the I picture is used.
In the case of 1 and P pictures, the subtraction unit 3 converts the signal sequence S1 to MC.
The inter-frame prediction error signal sequence S2 obtained by subtracting the inter-frame motion compensation prediction signal sequence S10 generated by the signal generation unit 13 is output to the signal S3.

The DCT section 5 includes blocks (8) for the signal S3.
Pixel x 8 lines) signal, 8 rows x 8 columns DCT
A matrix operation with the transform matrix is performed, and the transform coefficient signal sequence S4
Generate The quantizer 6 quantizes the transform coefficient with a predetermined characteristic to generate a coefficient quantized signal sequence S5. The quantization characteristic is controlled according to the buffer retention amount of the buffer unit 16 to secure a predetermined transmission bit rate.

The inverse quantizing unit 8 decodes the transform coefficient signal sequence S6 by the inverse quantizing process, and the IDCT unit 9 decodes D of 8 rows × 8 columns.
A matrix operation with a CT transformation inverse matrix is performed, and a signal S7 of an encoded image signal sequence for an I picture and an inter-frame prediction error signal sequence for a P picture are decoded. Then, the addition unit 10
Adds the inter-frame motion compensation prediction signal sequence S10 to decode the coded image signal sequence for P picture. The switch 11 is connected to the terminal a for an I picture and to the terminal b for a P picture, and the decoded encoded image signal sequence S is decoded.
8 is output. The frame memory unit 12 generates the signal S9 delayed by one frame period.

The motion vector detection unit 2 extracts a motion vector MV that matches the scan conversion processing of motion compensation in the decoding unit, according to the image information PI. That is, as shown in the scanning line interpolation of FIG. 1 in the case where the image signal is interlaced scanning, the motion vectors V ₀ , V ₁ and V ₂ are used in the inter-frame coding.
Extract (V _x = 2 m, V _y = 2 n). When the image signal is non-interlaced, the motion vector shown in the scanning line interpolation in FIG. 2 is extracted. The motion vector is extracted by a block matching method or the like. Then, the MC signal generation unit 13 performs motion compensation processing on the signal S9 with the motion vector MV, and the inter-frame motion compensation prediction signal sequence S10.
Generate

The VLC units 7 and 14 perform a predetermined variable length coding process on the coefficient quantized signal sequence S5 and the motion vector MV to generate a coded image data sequence S11 and a coded motion vector sequence S12. Then, the multiplexing unit 15 performs a process of time-divisionally multiplexing various data such as the coding parameter of the image information PI, the coded image data series S11, and the coded motion vector series S12 to generate the coded data series. Input S13 to the buffer unit 16.

A signal is read from the buffer section 16 at a constant bit rate to generate a coded bit stream signal PCD. Although not shown in the drawing, this signal PCD is a predetermined channel coding such as a code error countermeasure or digital modulation depending on the transmission medium (for example, digital modulation such as multilevel QAM or multilevel VSB in digital broadcasting). ) And transmit.

In the decoding section shown in FIG. 3B, the decoded bit stream signal PCD decoded by channel decoding is
Input to the buffer unit 17. Then, the encoded data sequence S13 read from the buffer unit is the DMPX unit 18
Then, the encoded image data series S11, the encoded motion vector series S12, and various data such as the encoding parameters of the image information PI are separated.

The IVLC units 19 and 20 perform a variable length code decoding process to decode the coefficient quantized signal sequence S5 and the motion vector MV.

The inverse quantizing unit 8 decodes the transform coefficient signal sequence S4 by the inverse quantizing process, and the IDCT unit 9 performs matrix calculation with the DCT transform inverse matrix of 8 rows × 8 columns. Then, the signal S3 corresponding to the coded image signal sequence is decoded for the I picture, and the signal S3 corresponding to the inter-frame prediction error signal sequence is decoded for the P picture. The addition unit 21 adds the inter-frame motion compensation prediction signal sequence S10 generated by the MC signal generation unit 24, and decodes the coded image signal sequence S14 for P picture. The switch 22 is connected to the terminal a for the I picture and to the terminal b for the P picture, and obtains the decoded coded image signal sequence S15 at its output.

The frame memory section 23 generates the signal S9 delayed by one frame period, and the MC signal generation section 24.
Performs motion compensation processing on this signal using the motion vector MV to obtain an inter-frame motion compensation prediction signal sequence S1.
Generates 0.

The MC interpolator 25 calculates the motion vector MV,
Based on the image information PI and the inter-frame prediction error signal series of the signal S3, the scan conversion processing of motion compensation as shown in FIG. 1'or FIG. 2 is performed, and the main signal series S16 and the interpolation signal series S17 are obtained. To generate. The details of this operation will be described later.

The post-processing unit 26 performs image format conversion processing, interlace-non-interlace scanning conversion or frame number conversion processing, and conversion into an analog signal to decode the non-interlaced scanning image signal VSD. To do. This signal is presented on a non-interlaced scanning image display unit (not shown in the drawing) to receive a high quality and high definition image.

The description of the overall block configuration is completed above, and then the MC interpolator 25 will be described with reference to the embodiments shown in FIGS.

FIG. 5 is a diagram of the first configuration example, which is suitable when the precision of the motion vector used in the scan conversion process of motion compensation is extremely high.

The decoded coded image signal sequence S15 is input to the field memory unit 27-1 and the MCIP unit 29. The field memory unit delays the signal for one field period. Then, the main signal sequence S16 is generated by this output signal. Further, this signal is delayed by one field period in the field memory unit 27-2 to generate a signal S9 delayed by one frame period with respect to the signal S15. The portion surrounded by the dotted line in the figure corresponds to the frame memory unit 23 shown in FIG. Therefore, this portion can be configured to be shared as a frame memory.

The interpolation MV generating unit 28 determines whether the scan conversion for motion compensation is interlace / non-interlace scan conversion or frame number conversion in the image information PI.
Then, as shown in FIG. 1 for the former case and as shown in FIG. 2 for the latter case, the interpolated motion vector IMV necessary for generating the interpolated signal for motion compensation is generated based on the motion vector MV. For example, in FIG. 1A, when the motion vector MV is V ₀ , the scanning line α of the signal S9 and the scanning line α ′ of the signal S15.
Of the signal S1 and the signal S1 in the case of V ₁
Interpolation motion vector I for specifying the signal of scanning line β ′
Generate MV.

The MCIP unit 29 takes out the signal of the scanning line designated by the interpolated motion vector IMV from the signals S9 and S15, creates an interpolated signal for motion compensation by the average value of both signals, and interpolated signal series S17. To generate.

Next, FIGS. 6 and 7 show this second configuration example. This is suitable even when the accuracy of the motion vector is slightly poor.

In the configuration example shown in FIG. 6, the field memory units 27-1 and 27-2 form a frame memory, and like the first configuration example, the signal of the main signal sequence S16 and the motion compensation signal are used. The signal S15 used for the scan conversion processing,
And, a signal S9 delayed by one frame period with respect to this signal is generated. The portion surrounded by the dotted line in the figure corresponds to the frame memory unit 23 shown in FIG.
In this embodiment, this portion can be shared.

The MC interpolation controller 30 controls the motion vector MV.
, The image information PI, and the inter-frame difference signal component for motion compensation obtained by the signal S3, the interpolated motion vector IMV necessary for generating the interpolated signal for motion compensation, and the motion adaptation coefficient k.
Generate m, 1-km. The image information PI determines whether the scan conversion for motion compensation is interlace-non-interlace scan conversion or frame number conversion. And
In the former case, as shown in FIG. 1 and in the latter case, as shown in FIG. 2, an interpolating motion vector IMV necessary for generating an interpolating signal for motion compensation is generated. However, unlike the first configuration example, this interpolation motion vector IMV is generated with the characteristic shown in FIG.
For each block (8 pixels × 8 lines), the prediction error signal of the signal S3, that is, the sum of absolute values Σ | S3 | of the motion compensation inter-frame difference signal components is measured. Then, when this is less than the threshold Th, it is determined that the accuracy of the motion vector is high,
Similar to the first configuration example, the interpolation motion vector IMV is generated based on the motion vector MV. On the other hand, when Σ | S3 | is equal to or greater than the threshold Th, it is determined that the accuracy of the motion vector is poor, and 0 is generated as the interpolation motion vector. Further, as shown in FIG. 7B, the motion adaptive coefficient km generates a coefficient value of a characteristic that changes from 0 to 1 according to the value of Σ | S3 |.

The MCIP unit 29 takes out the signal of the scanning line designated by the interpolation motion vector from the signals S9 and S15, and calculates the motion compensation interpolation signal S by the average value of both signals.
18 is generated. Since IMV = 0 when the accuracy of the motion vector is poor, the signal S18 is equivalent to the interpolation signal in the still mode of the conventional technique.

The intra-field interpolating unit 31 performs intra-field arithmetic processing based on the signal S16, and generates the interpolating signal S19 of a moving image similar to that in the moving image mode of the prior art with the same field signal.

The coefficient weighting unit 32-1 weights the signal S18 with the motion adaptation coefficient 1-km, and the coefficient adding unit 32-2 weights the signal S19 with the motion adaptation coefficient km. Then, the addition unit 33 adds the both signals to generate an interpolated signal sequence S17.

Next, FIG. 8 shows this third configuration example.
This is suitable even when the accuracy of the motion vector is considerably poor.

In the configuration diagram of FIG. 9A, the field memory units 27-1 and 27-2 form a frame memory, and the main signal sequence S16 is used as in the first and second configuration examples.
Signal and the signal S1 used for the scan conversion process of motion compensation
5 and a signal S9 obtained by delaying this signal by one frame period are generated. Since the portion surrounded by the dotted line in the figure corresponds to the frame memory unit 23 shown in FIG. 3, the portion shown in FIG. 3 can be configured to be shared.

The subtractor 34 subtracts the signals S15 and S9 to generate an inter-frame difference signal S20.

The MC interpolation control unit 35 uses the motion vector MV.
, The image information PI, the inter-frame difference signal component of the motion compensation of the signal S3, and the inter-frame difference signal S20, the interpolated motion vector IMV and the motion adaptation coefficients km and 1-km.
Generate The image information PI determines whether the scan conversion for motion compensation is interlace-non-interlace scan conversion or frame number conversion. Then, in the former case, the interpolating motion vector necessary for generating the interpolating signal for motion compensation shown in FIG. 1 and in the latter case is generated with the characteristic shown in FIG. That is, IMV = 0 is generated for the interpolation motion vector in the I picture. On the other hand, the P picture is generated by the magnitude of the inter-frame difference signal component for motion compensation. That is, the signal S3 is set in block (8 pixels × 8 lines) units.
The absolute value sum Σ | S3 | Then, when this is less than the threshold Th, it is determined that the accuracy of the motion vector is high,
A corresponding interpolated motion vector is generated based on the motion vector MV. On the other hand, when the threshold value is equal to or higher than Th, it is determined that the accuracy of the motion vector is poor, and IMV = 0 is generated as the interpolated motion vector. Also, the motion adaptation coefficient km is Σ for P pictures.
The magnitude of | S3 |, and the magnitude of the absolute value | S20 | of the difference signal between frames for an I picture, generate a coefficient value that varies in the range of 0 to 1.

The MCIP unit 29 takes out the signal of the scanning line designated by the interpolation motion vector from the signals S9 and S15, and calculates the motion compensation interpolation signal S by the average value of the two signals.
18 is generated. If the motion vector of the I picture and P picture has poor accuracy, IMV = 0, and thus the signal S18 is equivalent to the conventional still mode interpolation signal.

The intra-field interpolating unit 31 performs intra-field arithmetic processing based on the signal S16, and generates the interpolating signal S19 of the moving image corresponding to the moving image mode with the signal of the same field as in the prior art.

In the coefficient weighting units 32-1 and 32-2, the motion adaptive coefficients 1-km and km are added to the signals S18 and S19, respectively.
The coefficient values of 1 are weighted, and both signals are added by the adder 33 to generate an interpolated signal sequence S17.

It should be noted that the motion adaptive coefficient km in the second and third configuration examples is preferably realized by the characteristic that the coefficient value changes stepwise as shown in the figure, but depending on the case, 0 or 1 of 2 is used. It can also be realized by value characteristics.

Next, a configuration example of the post-processing section 26 will be described with reference to FIG. The main signal sequence S16 and the interpolation signal sequence S17 are the image format conversion units 36-1 and 36-2.
And performs image format conversion processing from the encoded image signal series to the original scanning format image signal format, and an image series V including a luminance signal and two color difference signals
Decrypt MS and VIP. The horizontal time compression unit 37-1,
37-2 is a signal process for compressing the time axis in the horizontal direction by half in interlaced to non-interlaced scanning conversion according to the image information PI, and in frame number conversion, for example, 30 to 60 conversion in the standard mode is performed in the time direction. Signal processing is performed to compress the time axis in half. Then, the time division multiplexing unit 38 time-divisionally multiplexes both signals to generate an image sequence VP in the form of non-interlaced scanning. RGB converter 39
Performs the predetermined matrix calculation processing and the three primary colors RG
It is converted into the B series image series VR. Then, the DA converter 4
At 0, conversion into an analog signal is performed and the non-interlaced scanning image signal VSD is decoded.

The other block parts in FIG. 3 may be configured in the same manner as the coding part and the decoding part of the conventional MPEG1 and 2 video coding, and the description thereof will be omitted.

As described above, according to this embodiment, there is no interlace interference or judder interference, and high quality
An image signal encoding / decoding device for receiving a high-definition image can be realized, and a remarkable effect in image quality improvement can be achieved.

Next, regarding the second embodiment of the present invention,
This will be described with reference to the overall block diagram shown in FIG. In the present embodiment, the decoding unit selects one of the motion vectors that is suitable for the scan conversion processing for motion compensation, and the one suitable for decoding the image signal of the non-interlaced scanning using the selected motion vector. Is. In the present embodiment, the case of video coding conforming to MPEG1 and MPEG2 in which motion compensation predictive coding between frames and DCT orthogonal transform coding are combined will be described as an example.

In the encoding unit shown in FIG. 9A, the image signal VS
Is digitized by the preprocessing unit 1 and subjected to predetermined image format conversion to generate an encoded image signal sequence S1. That is, a signal sequence of a macro block composed of 6 blocks (4 luminance signal blocks and 2 color difference signal blocks, block size is 8 pixels × 8 lines) is generated.

The switches 4 and 11 switch the DCT in the frame.
If the encoding mode for encoding is I picture, the terminal a,
In the P picture, the coding mode for performing the motion compensation interframe predictive coding and the DCT coding is connected to the terminal b. Then, to the DCT unit 5, the encoded image signal sequence S1 of the original image for an I picture and the inter-frame prediction error signal sequence S2 for a P picture are input as a signal S3, respectively. The subtraction unit 3 generates an inter-frame prediction error signal sequence S2 by subtracting the inter-frame motion compensation prediction signal sequence S10 and the encoded image signal sequence S1 generated by the MC signal generation unit 13.

The DCT section 5 includes each block (8
Matrix operation with a DCT transform matrix of 8 rows × 8 columns is performed in units of (pixel × 8 lines) to generate a transform coefficient signal sequence S4. The quantizer 6 quantizes the transform coefficient to generate a coefficient quantized signal sequence S5. In order to secure a predetermined transmission bit rate, the quantization processing is performed by changing the characteristics according to the buffer retention amount of the buffer unit 16.

The inverse quantization unit 8 decodes the transform coefficient signal sequence S6 by the inverse quantization process, and the IDCT unit 9 performs matrix operation with the DCT transform inverse matrix of 8 rows × 8 columns. Then, the signal S7 of the encoded image signal sequence at the time of e-picture and the inter-frame prediction error signal sequence at the time of P-picture are decoded. Adder 1
0 performs addition processing with the inter-frame motion compensation prediction signal sequence S10 to decode the coded image signal sequence for P picture. The switch 11 is connected to the terminal a for an e-picture and to the terminal b for a P-picture, and the decoded coded image signal sequence S8 of its output is input to the frame memory unit 12 and its output is delayed by one frame period. Obtain S9.

The motion vector detecting unit 41 uses the block matching method or the like to calculate the motion vector MV for one frame period.
To extract. Note that, unlike the first embodiment, the scan conversion process of motion compensation in the decoding unit also includes an inconvenient motion vector. The MC signal generation unit 13 performs motion compensation processing on the signal S9 using the motion vector MV to generate an inter-frame motion compensation prediction signal sequence S10.

The VLC units 7 and 14 perform a predetermined variable length coding process on the coefficient quantized signal sequence S5 and the motion vector MV to generate a coded image data sequence S11 and a coded motion vector sequence S12. To do. The multiplexing unit 15 performs a process of multiplexing the signal sequences S11 and S12 and various data such as the encoding parameter of the image information PI in a predetermined time series, and outputs the encoded data sequence S13 to the buffer unit 16. input. Then, the coded bit stream signal PCD is generated by reading from the buffer unit 16 at a constant bit rate. Although not shown in the drawing, the signal PCD is transmitted after performing a predetermined channel coding such as a code error countermeasure or digital modulation according to the transmission medium.

In the decoding section shown in FIG. 9B, the coded bit stream signal PCD decoded by channel decoding is
Input to the buffer unit 17. Then, the encoded data sequence S13 read from the buffer unit is the DMP × unit 18
Then, the coded image data series S11, the coded motion vector series S12, and various data of the image information PI are separated.

The IVLC units 19 and 20 perform a variable length code decoding process to decode the coefficient quantized signal sequence S5 and the motion vector MV, respectively.

The inverse quantizing unit 8 decodes the transform coefficient signal sequence S4 by the inverse quantizing process, and the IDCT unit performs matrix operation with the DCT transform inverse matrix of 8 rows × 8 columns. Then, the signal S3 corresponding to the coded image signal sequence at the time of e-picture and the inter-frame prediction error signal sequence at the time of P-picture, respectively.
To decrypt. In addition, the addition unit 21 includes the MC signal generation unit 24.
The inter-frame motion-compensated prediction signal sequence S10 generated in step S12 is added, and the encoded image signal sequence S for P picture is added to the output.
14 is generated. The switch 22 is connected to the terminal a for e-picture and the terminal b for P-picture, and obtains the decoded coded image signal sequence S15 at its output.

The frame memory unit 23 delays the input signal by one frame period to generate a signal S9. And M
The C signal generation unit 24 outputs this signal S9 to the motion vector MV.
Then, motion compensation processing is performed to generate an inter-frame motion compensation prediction signal sequence S10.

The MV selector 42 responds to the image information PI.
Of the motion vector MV.
The process of selecting the one that matches the reason is performed. That is,
When the image signal is interlaced scan, scan line interpolation in FIG.
Motion vector V as shown in ₀, V₁, V₂The non-in
In the tare scan, the motion vector as shown in the scan line interpolation in FIG.
The area where the cutout is selected is H, and the area where it is not selected is L.
A signal selection region signal MCM is generated.

The MC interpolating unit 43 uses the selection motion vector M.
V ', the selection area signal MCM, the image information PI, and the inter-frame prediction error signal sequence of the signal S3 are subjected to the scan conversion processing of motion compensation shown in FIGS. 1 and 2, and the main signal sequence S16 and the interpolation signal. And the sequence S17. The configuration and operation will be described later in detail.

The post-processing unit 26 performs image format conversion processing, interlaced to non-interlaced scanning conversion by the main signal series S16 and the interpolation signal series S17, frame number conversion processing, and conversion into analog signals. , The non-interlaced scanning image signal VSD is decoded. Then, this signal is displayed on a non-interlaced scanning image display unit (not shown in the drawing) to receive a high quality and high definition image.

FIG. 11 is a diagram showing an example of the configuration of the MC interpolation unit 43. The field memory units 27-1 and 27-2 delay the signal for one field period, and the portion surrounded by the dotted line in the figure corresponds to the frame memory. For the main signal sequence S16 and the scan conversion processing for motion compensation. Signal S1 to be used
5, and a signal S obtained by delaying this signal for one frame period
9 and.

The motion detector 44 extracts the difference component between frames by the subtraction processing of the signals S15 and S9, and generates the motion information MI between frames (0 when stationary) based on this difference component.

The MC interpolation control unit 45 generates the interpolation motion vector IMV and the motion adaptive coefficients km and 1-km required for generating the interpolation signal for motion compensation. This operation schematic is shown in FIG.
It is shown in FIG. In the first characteristic of FIG. 10A, when the selection area signal MCM is H, the interpolation motion vector is based on the selection motion vector MV ′, and in the interlaced to non-interlaced scan conversion, the interpolation motion vector shown in FIG. In the conversion, the IMV necessary for generating the interpolation signal for motion compensation shown in FIG. 2 is generated. On the other hand, when the selection area signal MCM is L, 0 is generated in the interpolation motion vector. Further, the motion adaptive coefficient km generates a coefficient value of a characteristic that changes from 0 to 1 according to the level of the motion information MI between frames when the selection area signal MCM is H, and when km = 0. Therefore, according to this characteristic, an interpolation signal is generated by the motion-compensating scan conversion process in the H region of the selection region signal MCM and by the motion adaptation process similar to the conventional technique in the L region.

On the other hand, in the second characteristic of FIG. 9B, the interpolation motion vector is such that the selection area signal MCM is H and the signal S3 is
Prediction error signal, that is, when the sum of absolute values Σ | S ₃ | (for example, a block unit of 8 pixels × 8 lines) of inter-frame difference signal components of motion compensation is less than a threshold Th, a selection motion vector MV ′ is also included. And generate. In other cases, 0 is generated in the interpolation motion vector. Further, the motion adaptive coefficient km is Σ | S _{3 in} the area where the selection area signal is H.
The coefficient value of the characteristic that changes from 0 to 1 corresponding to the value of |
In the area where the selection area signal is L, the motion information M between frames is
A coefficient value of a characteristic that changes from 0 to 1 corresponding to I is generated.

Returning to FIG. 11, the MCIP unit 29 takes out the signals of the scanning lines of the signal S9 and the signal S15 designated by the interpolation motion vector IMV, and generates the motion compensation interpolation signal S18 by the average value of both signals. . IMV = 0
In this case, the signal S18 will generate an interpolation signal equivalent to that in the stationary mode in the prior art.

The intra-field interpolating unit 31 performs intra-field arithmetic processing based on the signal S16, and generates a moving image interpolating signal S19 similar to that in the moving image mode of the prior art, using the same field signal.

The coefficient weighting unit 32-1 weights the signal S18 with the motion adaptation coefficient 1-km, and the coefficient weighting unit 32-2 weights the signal S19 with the motion adaptation coefficient km. Then, the both signals are added by the adder 33 to generate the interpolated signal sequence S17.

The portion surrounded by the dotted line in the figure is shown in FIG.
Of the frame memory unit 23. Therefore, FIG.
In this embodiment, this part can be shared.

As described above, according to this embodiment, an image signal encoding / decoding device capable of receiving a high-quality and high-definition image without interlace interference or judder interference can be provided, and the image quality can be improved. A remarkable effect can be obtained. Further, the configuration of the decoding unit shown in this embodiment can also be used as the decoding unit in the first embodiment.

In the present invention, the configuration of the decoding section can be realized in various forms other than the first and second embodiments.

FIG. 13 is an overall block diagram of the third embodiment of the decoding unit.

The channel-decoded coded bit stream signal PCD is input to the buffer unit 17. And
The encoded data sequence S13 read from the buffer unit is
It is input to the video decoding unit 46. The video decoding unit corresponds to the portion surrounded by the dotted line in FIGS. 3 and 10, performs the above-described video decoding processing, and decodes the encoded image signal sequence S15, the motion vector MV, and the P picture of the signal S3. The inter-frame prediction error signal sequence at time and the image information PI are output.

The image format conversion section 47 performs image format conversion processing on the coded image signal series to generate an image signal series VFC in the original scanning form.

The MC interpolator 48 is shown in FIG. 1 for interlaced to non-interlaced scan conversion and is shown in FIG. 2 for frame number conversion.
The motion conversion scan conversion processing shown in (1) is performed to generate a main signal series S16 and an interpolation signal series S17. That is, the interpolation motion vector IMV generated based on the motion vector MV and the signal S with the same configuration as in FIGS.
An interpolating signal sequence S17 is created using the motion adaptive coefficients km and 1-km generated by the motion compensation inter-frame difference signal detected from 3.

According to the image information PI, the non-interlaced sequence conversion unit 49, in the case of interlaced to non-interlaced scan conversion, the main signal sequence S16 and the interpolation signal sequence S1.
7, the time axis is horizontally compressed to 1/2, and in the case of the frame number conversion, for example, 30 to 60 conversion in the standard mode, the time axis is vertically compressed to 1/2. Then, both compressed signals are time-sequentially multiplexed to generate a non-interlaced scanning signal, RGB primary color RGB conversion and analog conversion are performed, and a non-interlaced scanning image signal V is generated.
Restore SD.

The present embodiment is suitable for video encoding with a motion vector in a form suitable for scan conversion processing of motion compensation in the motion compensation predictive encoding in the encoding unit.
It is possible to realize a decoding device which receives a high-quality and high-definition image without interlace interference or judder interference.

FIG. 14 is an overall block diagram of the fourth embodiment of the decoding section.

The channel-decoded coded bit stream signal PCD is input to the buffer unit 17. And
The encoded data sequence S13 read from the buffer unit is
It is input to the video decoding unit 46. This is shown in FIGS.
Corresponding to the part surrounded by the dotted line, and is subjected to the above-described video decoding processing to obtain the decoded encoded image signal sequence S15.
, The motion vector MV, the inter-frame prediction error signal sequence (corresponding to the inter-frame difference signal for motion compensation) at the time of the P picture of the signal S3, and the image information PI are output.

The MV selector 42 performs a process of selecting, from the motion vector MV, one that matches the scan conversion process of motion compensation, according to the image information PI. That is, when the image signal is an interlaced scan, the motion vector shown in the scan line interpolation of FIG. 1 is generated as the selected motion vector MV ′ and the motion vector shown in the scan line interpolation of FIG. 2 is generated as the non-interlaced scan. Further, the selection area signal MCM of H is used for the area where the motion vector is selected and L is used for the area where the motion vector is not selected.
Generate

The image format conversion section 47 performs an image format conversion process for converting the encoded image signal sequence into the original scanning mode signal sequence, and outputs the image signal sequence VF.
Generate C.

The MC interpolator 50 performs the signal conversion process shown in FIG. 1 for the motion conversion scan conversion process, that is, the interlaced to non-interlaced scan conversion, and the frame number conversion shown in FIG. 2 to interpolate the main signal sequence S16. Signal sequence S17
Produces and. This can be realized by the configurations and characteristics shown in FIGS. Then, the interpolation motion vector IMV
And the motion adaptive coefficients km and 1-km are used to generate the interpolated signal sequence S17.

The non-interlaced sequence converter 49 performs a time axis compression process on the main signal sequence S16 and the interpolated signal sequence S17. That is, according to the image information PI, in the case of interlaced to non-interlaced scan conversion, it is 1/2 in the horizontal direction, for example, 30 to 6 in the standard mode of frame number conversion.
In the 0 conversion, 1/2 compression is performed in the time direction. And
Both compressed signals are time-sequentially multiplexed to generate a non-interlaced scanning signal, RGB primary color RGB conversion and analog conversion are performed, and the non-interlaced scanning image signal VSD is decoded.

According to this embodiment, it is possible to realize a decoding device which receives a high-quality and high-definition image without interlace interference or judder interference.

In the above description of the embodiments, a combination of inter-frame motion compensation predictive coding and DCT transform coding has been described as an example of video coding, but the present invention is not limited to this, and various forms are possible. It is obvious that the present invention can also be applied to the coding by the combination of the motion compensation predictive coding and the orthogonal transform coding.

[0100]

According to the present invention, an image signal encoding / decoding system and apparatus capable of receiving a high-quality and high-definition image free from interlace interference and judder interference can be realized, and the image quality of the image can be improved or improved. A remarkable effect is obtained.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram showing the principle of predictive coding for motion compensation and scan line interpolation.

FIG. 3 is a schematic diagram of the principle of motion compensation predictive coding and scan line interpolation.

FIG. 4 is a schematic diagram of an encoding mode.

FIG. 5 is a first configuration example diagram of an MC interpolation unit.

FIG. 6 is a second configuration example diagram of an MC interpolation unit.

FIG. 7 is an operation schematic diagram of an MC interpolation control unit.

FIG. 8 is a third configuration example diagram of an MC interpolation unit.

FIG. 9 is a diagram showing a configuration example of a post-processing unit.

FIG. 10 is an overall block configuration diagram of a second embodiment of the present invention.

FIG. 11 is a diagram showing a configuration example of an MC interpolating unit according to the second embodiment.

FIG. 12 is a schematic characteristic diagram of an MC interpolation control unit in the second embodiment.

FIG. 13 is an overall block configuration diagram of a third embodiment of a decoding unit of the present invention.

FIG. 14 is an overall block configuration diagram of a fourth embodiment of a decoding unit of the present invention.

[Explanation of symbols]

1 ... Preprocessing unit, 2, 41 ... Motion vector detection unit, 3, 3
4 ... Subtraction unit, 4, 1122 ... Switch, 5 ... DCT unit,
6 ... Quantization unit, 7, 14 ... VLC unit, 8 ... Inverse quantization unit,
9 ... IDCT unit, 10, 21, 33 ... Addition unit, 12, 2
3 ... Frame memory unit, 13, 24 ... MC signal generation unit,
15 ... MPX section, 16, 17 ... Buffer section, 18 ... DM
PX section, 19, 20 ... IVLC section, 25, 43, 48,
50 ... MC interpolation unit, 26 ... Post-processing unit, 27 ... Field memory unit, 28 ... Interpolation MV generation unit, 29 ... MCIP unit,
30, 35, 45 ... MC interpolation control unit, 31 ... In-field interpolation unit, 32 ... Coefficient weighting unit, 36, 47 ... Image format conversion unit, 37 ... Horizontal time compression unit, 38 ... Time division multiplexing unit, 39 ... RGB Conversion unit, 40 ... DA conversion unit, 42 ...
MV selection unit, 44 ... Motion detection unit, 46 ... Video decoding unit, 49 ... Non-interlaced sequence conversion unit.

Claims (7)

[Claims] 1. An encoding / decoding system and apparatus for an image signal, which transmits and receives a high-efficiency encoded signal by video encoding in which motion compensation predictive encoding and orthogonal transform encoding are combined. The section is provided with means for extracting a motion vector suitable for the scan conversion processing for motion compensation, and the decoding section is provided with means for interlace-to-non-interlace conversion of the decoded image signal or scan conversion means for performing frame number advance conversion. An image signal encoding / decoding system and apparatus characterized by performing scan-compensated signal processing of motion compensation for generating an interpolated scan line signal based on a decoded motion vector in scan conversion. 2. An image signal encoding / decoding system and apparatus for transmitting and receiving a signal obtained by highly efficiently encoding an image signal by video encoding in which motion compensation predictive encoding and orthogonal transform encoding are combined. The section is provided with means for selecting a motion vector suitable for scanning conversion for motion compensation from the decoded motion vector, and means for scanning conversion for performing interlaced to non-interlaced conversion or frame number conversion of the decoded image signal, An image signal encoding / decoding system and apparatus characterized by performing scan conversion signal processing of motion compensation for generating an interpolation scanning line signal based on a selected motion vector in scan conversion. 3. The scan-converted signal processing for motion compensation of a signal according to claim 1, wherein when the absolute value of the inter-frame difference signal for motion compensation is less than a threshold Th, a decoded vegetation vector and a threshold Th.
The above is the motion compensation interpolation signal generated by the zero motion vector and the motion compensation signal generated by the signal processing in the field according to the magnitude of the absolute value of the inter-frame difference signal for motion compensation. An image signal encoding / decoding system and apparatus, wherein an interpolation scanning line is generated by changing a mixing comfort of an interpolation signal of compensation and an interpolation signal of the moving image. 4. In an image signal whose coding mode is intraframe coding (e-picture), the absolute value of the difference signal between frames is large or small, and the coding mode is interframe coding (P-picture).
In this image signal, an interpolating scan line signal is generated by changing the mixing ratio of the motion compensating interpolation signal and the moving image interpolating signal according to the magnitude of the absolute value of the motion compensation inter-frame difference signal. The image signal encoding / decoding system and apparatus according to claim 3. 5. The motion-compensated scan conversion signal processing according to claim 2, wherein a motion vector-selected region is a motion vector selected, and a region not selected is a motion-compensated interpolation signal generated with a zero motion vector. And the interpolation signal of the moving image generated by the signal processing in the field, the area where the motion vector is selected is a motion compensation interpolation signal, and the area where the motion vector is not selected is determined according to the absolute value of the difference signal between frames. An image signal encoding / decoding system and apparatus, wherein an interpolation scanning line signal is generated by a signal in which a mixing ratio of a motion compensation interpolation signal and a moving image interpolation signal is changed. 6. The motion-compensated scan conversion signal processing according to claim 2, wherein a motion vector is selected, and a motion vector is selected in an area in which an absolute value of a motion-compensation inter-frame difference signal is less than a threshold Th. In areas other than the above, the motion-compensated interpolation signal generated by a motion vector of zero and the interpolated signal of the moving image generated by the signal processing in the field are used. In the area where the absolute value of the motion vector is not selected and the motion vector is not selected, the mixing ratio of the interpolation signal for motion compensation and the interpolation signal for the moving image is changed according to the absolute value of the difference signal between frames to change the interpolation scanning line. An image signal encoding / decoding system and apparatus characterized by generating a signal. 7. Video coding in combination with motion compensation predictive coding and orthogonal transform coding is an international standard MPEG1.
Alternatively, the image signal encoding / decoding system and apparatus according to any one of claims 1 to 6, wherein the encoding is based on the MPEF2 video encoding system.