TW201626797A - Video image encoding device, video image decoding device, video image encoding method, video image decoding method, and program - Google Patents

Abstract

A video image encoding device includes an adaptive color-difference quantization offset derivation unit capable of selecting the color space of a prediction error signal in encoding block units from a plurality of color spaces and deriving the quantization offset for each color space, and a dequantization unit for dequantizing a quantization coefficient image using the color-difference quantization offset for each color space.

Description

Video coding device, video decoding device, video coding method, video decoding method and program

The present invention relates to a video encoding apparatus and a video decoding apparatus using a residual domain adaptive color conversion and a color difference quantization offset.

In the video coding method based on HEVC (High Efficiency Video Coding)/H.265, each frame of the digitized image is divided into a coding tree unit (CTU: Coding Tree Unit), and each CTU It is encoded in the order of Raster scan. The CTU is coded by dividing into a coding unit (CU: Coding Unit) by a quadtree structure. Each CU is divided into prediction units (PU: Prediction Unit) and predicted. Further, the prediction error of each CU is divided into a conversion unit (TU: Transform Unit) by a quaternary tree structure to perform frequency conversion.

CU-based intra-prediction (Intra Pridiction)/inter-frame prediction coding unit.

Intra prediction (intra-picture prediction) generates a prediction signal from a reconstructed image of a coded object frame. There are 33 angular intra predictions and the like defined in HEVC/H.265. The angle intra prediction generates an intra prediction signal by extrapolating the reconstructed pixels in the vicinity of the coding target block in any of 33 directions.

In terms of intra prediction, in addition to angular intra prediction, DC (Direct Current) prediction and Planar prediction are also specified. In the DC prediction, the average value of the reference image is determined as the predicted value of all the pixels of the prediction target TU. In planar prediction, the predicted image is generated from the pixels in the reference image by linear interpolation.

Inter-frame prediction is based on the prediction of the image of the next: the object frame of the encoding; and the reconstructed frame (reference picture) indicating the different moments. Inter-frame prediction is also known as Inter Prediction. Inter prediction is based on the reconstructed image block of the reference image (using pixel interpolation if necessary) to generate an inter prediction signal.

Digital color images are composed of digital images of R, G, and B. However, when color images are transmitted via a transmission path, signals for color space other than RGB space are usually converted to improve compression efficiency (in order to reduce the amount of data). . For example, a signal that converts an image signal into a color space (YCoCr space) of a combination of a luminance signal (Y) and a color difference signal (Cb, Cr).

The quantization parameter (QP) for the color difference signal is generated by converting the QP for the luminance signal using an offset value called chroma_qp_index_offset. In HEVC, cb_qp_index_offset (first color difference quantization offset) is applied to Cb, and cr_qp_index_offset (second color difference quantization offset) is applied to Cr.

In the RExt (Range Extension, range extension) of HEVC, standardization work of the expansion function has been performed (refer to Non-Patent Document 1).

In order to further improve the compression efficiency of the extended function brought about by RExt, a non-patent document 2 proposes a technique called an adaptive color transform in residual domain. As shown in FIG. 17, the residual domain adaptive color conversion is a technique of adaptively switching the prediction error signal of the image signal of the RGB space into a YCoCr space in block units.

That is, the RGB prediction error signal can be directly compressed in block units or converted into a YCoCr space signal using the following Forward color space conversion matrix (refer to Equation (1)) and compressed. In addition, FIG. 17 shows an example in which blocks marked with diagonal lines are subjected to data compression in the YCoCr space, and other blocks are subjected to data compression in RGB space.

The color space information utilized by the data compression of the block is signaled by the cu_residual_csc_flag syntax. Cu_residual_csc_flag=0 means that the signal of the RGB space is compressed, and cu_residual_csc_flag=1 means that the signal is compressed after being converted into the YCoCr space.

In the case of cu_residual_csc_flag=1, the receiver (video decoding apparatus) performs the decoding process after returning the signal of the YCoCr space to the signal of the RGB space using the Backward color space conversion matrix described below. Forward : = /4 (1) Backward: = /4

In addition, since the norm is not fixed in the color conversion matrix described above, when cu_residual_csc_flag=1, the quantization processing and the inverse quantization processing of the prediction error signal of the block will be different for each YCoCr component. The color difference quantization offset is added to the quantization parameter.

Further, Patent Document 1 describes a video encoding device and a video decoding device that perform different signal processing in a case where an input image signal is a signal of an RGB space and a YCoCr space is used. Specifically, when performing the weighted prediction based on the H.264/AVC method, the video encoding apparatus applies the same bias to the R, G, and B signals and the luminance signal (Y signal) with respect to the offset of the addition to the prediction signal. Move and apply other offsets to the color difference signal. However, Patent Document 1 does not teach new insights regarding the quantization offset of the color difference. [Prior Art Document] [Patent Document 1]

Japanese Patent Laid-Open Publication No. 2011-151683 [Non-Patent Document 1]

D. Flynn, et al., "High Efficiency Video Coding (HEVC) Range Extensions text specification: Draft 7", JCTVC-Q1005, Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG 16 WP 3 and ISO /IEC JTC 1/ SC 29/ WG 11 17th Meeting: Valencia, ES, 27 March – 4 April 2014 [Non-Patent Document 2]

L. Zhang et al., "SCCE5 Test 3.2.1: In-loop color-space transform", JCTVC-R0147, Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/ SC 29/ WG 1118th Meeting: Sapporo, JP, 30 June – 9 July 2014

[The problem that the invention wants to solve]

Next, the configuration and operation of a general video encoding apparatus will be described with reference to FIG. 18. Generally, the video encoding apparatus outputs a bit stream by using each CU of each frame of the digitized video as an input video.

The video encoding apparatus shown in FIG. 18 includes a switcher 101, a color space converter 102, a switcher 103, a frequency conversion/quantizer 104, an inverse quantization/inverse frequency converter 105, a switch 106, an inverse color space converter 107, The switch 108, the buffer 109, the predictor 110, the prediction parameter determiner 111, the entropy encoder 112, the subtractor 115, and the adder 116.

The predictor 110 generates a prediction signal for the input video signal of the CU. Specifically, the predictor 110 generates a prediction signal (intra prediction signal) based on intra prediction, and generates a prediction signal (inter prediction signal) based on inter prediction.

The video input to the video encoding device is subtracted from the predicted video supplied from the predictor 110 by the subtractor 115, and then input to the switch 101 as a prediction error video. In the example shown in Fig. 18, the input image signal is a signal of the RGB space. In addition, the video encoding device has a residual domain adaptive color conversion function. For example, the video encoding device can adaptively switch the prediction error signal of the image signal of the RGB space into the signal of the YCoCr space in block units.

When the prediction error signal is processed in the RGB space, the switch 101 is set to input the prediction error image to the switch 103. When the prediction error signal is processed in the YCoCr space, the switch 101 is set to input the prediction error image to the color space converter 102. Further, the switch 101 sets the output destination of the prediction error video, for example, in accordance with the control of the prediction parameter determiner 111.

The color space converter 102 converts the prediction error signal of the RGB space into a signal of the YCoCr space using the above equation (1) (the forward color space conversion matrix), and outputs it to the switch 103.

When the prediction error signal is processed in the RGB space, the switch 103 outputs the prediction error signal from the switch 101 to the frequency conversion/quantizer 104. When the prediction error signal is processed in the YCoCr space, the switch 103 outputs the prediction error signal from the color space converter 102 to the frequency conversion/quantizer 104. Further, the switch 103 selects the input source of the prediction error image, for example, according to the control of the prediction parameter determiner 111.

The frequency conversion/quantizer 104 frequency-converts the prediction error image and quantizes the frequency-converted prediction error image (coefficient image). The entropy encoder 112 entropy encodes the prediction parameters and the quantized coefficient images to output a bit stream.

The inverse quantization/inverse frequency converter 105 inverse quantizes the quantized coefficient image. Furthermore, the inverse quantization/inverse frequency converter 105 performs inverse frequency conversion on the inverse quantized coefficient image. The reconstructed prediction error image that is inverse frequency converted is input to the switch 106.

When the prediction error signal is processed in RGB space, the switch 106 is configured to input the reconstructed prediction error image to the switch 108. When the prediction error signal is processed in the YCoCr space, the switch 106 is set to input the reconstructed prediction error image to the inverse color space converter 107. Further, the switch 106 selects, for example, the output destination of the reconstructed prediction error image in accordance with the control of the prediction parameter determiner 111.

The inverse color space converter 107 converts the reconstructed prediction error signal of the YCoCr space into a signal of the RGB space using the above equation (1) (inverse color space conversion matrix), and outputs it to the switch 108.

When the prediction error signal is processed in RGB space, the switch 108 selects the reconstructed prediction error signal from the switch 106. When the prediction error signal is processed in the YCoCr space, the switch 108 selects the reconstructed prediction error signal from the inverse color space converter 107. In addition, the switch 108 selects any of the reconstructed prediction error images, for example, according to the control of the prediction parameter determiner 111.

When the prediction signal is added by the adder 116, the reconstructed prediction error image from the switch 108 is supplied to the buffer 109 as a reconstructed image. The buffer 109 stores the reconstructed image.

The prediction parameter determiner 111 compares the input video signal with the prediction signal and, for example, instructs the predictor 110 in a manner that determines the prediction parameter with the smallest coding cost. The prediction parameter decider 111 supplies the determined prediction parameters to the entropy encoder 112. The prediction parameters are information related to block prediction such as prediction mode (intra prediction, inter prediction), intra prediction block size, intra prediction direction, inter prediction block size, and motion vector.

The prediction parameter determiner 111 further causes each block to decide to process the prediction error signal in RGB space or to process the prediction error signal in YCoCr space.

The bit stream output by the video encoding device is passed to the video decoding device. The video decoding device performs a decoding process to restore the motion picture. Fig. 19 is a block diagram showing an example of a configuration of a general video decoding device which decodes a bit stream output from a general video encoding device to obtain a decoded image. The configuration and operation of the general video decoding device will be described with reference to FIG.

The video decoding apparatus shown in FIG. 19 includes an entropy decoder 212, an inverse quantization/inverse frequency converter 205, a switch 206, an inverse color space converter 207, a switch 208, a buffer 209, a predictor 210, and an adder 216. .

The entropy decoder 212 entropy decodes the input bit stream. The entropy decoder 212 supplies the quantized coefficient image to the inverse quantization/inverse frequency converter 205 and supplies the prediction parameters to the predictor 210.

The inverse quantization/inverse frequency converter 205 inversely quantizes the input quantized coefficient image and outputs it as a coefficient image. Furthermore, the inverse quantization/inverse frequency converter 205 converts the coefficient image of the frequency domain into a spatial domain image and outputs it as a prediction error image. The prediction error image is input to the switch 206.

When the prediction error signal is processed in RGB space, the switch 206 is configured to input the prediction error image to the switch 208. When the prediction error signal is processed in the YCoCr space, the switch 206 is set to input the prediction error image to the inverse color space converter 207. In addition, the switch 206 can determine whether the prediction error signal should be processed in RGB space or the prediction error signal in YCoCr space by signaling from the video encoding device.

The inverse color space converter 207 converts the prediction error signal of the YCoCr space into a signal of the RGB space using the above equation (1) (inverse color space conversion matrix), and outputs the prediction error signal to the switch 208.

When the prediction error signal is processed in RGB space, the switch 208 selects the prediction error signal from the switch 206. When the prediction error signal is processed in the YCoCr space, the switch 208 selects the prediction error signal from the inverse color space converter 207. The switch 208 can determine whether the prediction error signal should be processed in the RGB space or the prediction error signal in the YCoCr space by the transmission from the video encoding device.

The prediction error image from the switch 208 is added to the predictor signal from the predictor 210 by the adder 216, and then supplied to the buffer 209 as a reconstructed image. The buffer 209 stores the reconstructed image.

Further, the reconstructed video stored in the buffer 209 is output as a decoded video (decoded video).

The buffer 209 accumulates the previously decoded video as a reference image. When the intra prediction is performed, the predictor 210 predicts the image of the decoding target from the previously decoded adjacent reconstructed image among the currently decoded images to generate a predicted image. When inter prediction is performed, the predictor 210 generates a predicted image based on the reference image supplied from the buffer 209.

Among RExt, the proposal has a color difference quantization offset (color difference QP offset) technique whose objective is to improve the subjective image quality. The color difference quantization offset technique will signal the color difference quantization offset values of the second color component and the third color component to adjust the quantization parameter of each color component. That is, the quantization intensity can be changed.

The following is a syntax for signaling the color difference quantization offset value.・Picture unit: pps_cb_qp_offset/pps_cr_qp_offset/slice_qp_delta_cb/slice_qp_delta_cr ・Slice unit: slice_qp_delta_cb/slice_qp_delta_cr ・Block unit: cu_chroma_qp_offset_idx

The subjective image quality can be improved by adjusting the quantization intensity of each color component by using the above grammar.

The video encoding device shown in Fig. 18 and the video decoding device shown in Fig. 19 are also applied to the color difference quantization offset. As shown in FIG. 18, the video encoding device inputs a predetermined color difference quantization offset.

In the video encoding device, when the frequency conversion/quantizer 104 processes the prediction error signal in the RGB space, when the coefficient image is quantized, as shown in FIG. 20, the B component is increased or decreased according to the first color difference quantization offset. Quantize the parameters and increase or decrease the quantization parameter of the R component according to the second color difference quantization offset. The inverse quantization/inverse frequency converter 105 increases or decreases the inverse quantization parameter of the B component according to the first color difference quantization offset, and increases or decreases the inverse quantization parameter of the R component according to the second color difference quantization offset.

When the frequency conversion/quantizer 104 processes the prediction error signal in the YCoCr space, when quantizing the coefficient image, as shown in FIG. 20, the quantization parameter of the Co component is increased or decreased according to the first color difference quantization offset, and the second parameter is followed. The color difference is quantized to increase or decrease the quantization parameter of the Cr component. The inverse quantization/inverse frequency converter 105 increases or decreases the inverse quantization parameter of the Co component according to the first color difference quantization offset, and increases or decreases the inverse quantization parameter of the Cr component according to the second color difference quantization offset.

Among the video decoding devices, the inverse quantization/inverse frequency converter 205 operates in the same manner as the inverse quantization/inverse frequency converter 105 in the video encoding device.

However, the color difference quantization offset technique is applied to the color difference quantization offset value of the second color component (second color component) and the third color component (third color component), so if the residual domain is adaptive color The conversion is combined with the color difference quantization offset, and as shown in FIG. 20, the block compressed in the RGB space shares the quantization intensity with the block compressed in the YCoCr space. Therefore, the quantization intensity cannot be appropriately set in accordance with the color space. Therefore, the subjective image quality improvement effect by the color difference quantization offset technique cannot be obtained.

The object of the present invention is to provide a video encoding device, a video decoding device, a video encoding method, a video decoding method, and a program, which do not lose subjective image quality improvement effects when combined with residual color adaptive color conversion and color difference quantization offset. . [The way to solve the problem]

The video encoding device of the present invention can select the color space of the prediction error signal from the plurality of color spaces in the coding block unit, and is characterized by: an adaptive color difference quantization offset deriving mechanism, and deriving the color difference of each color space. a quantization offset; and an inverse quantization mechanism that inverse quantizes the quantized coefficient image using the color difference quantization offset for each color space.

The video decoding device of the present invention can select the color space of the prediction error signal from the plurality of color spaces in the coding block unit, and is characterized by: an adaptive color difference quantization offset deriving mechanism, and deriving the color difference of each color space. a quantization offset; and an inverse quantization mechanism that inverse quantizes the quantized coefficient image using the color difference quantization offset for each color space.

The video encoding method of the present invention can select a color space of a prediction error signal from a plurality of color spaces in a coding block unit, and is characterized by: deriving a color difference quantization offset of each color space, and using each color space. The color difference is quantized and the quantized coefficient image is inverse quantized.

The video decoding method of the present invention can select a color space of a prediction error signal from a plurality of color spaces in a coding block unit, and is characterized by: deriving a color difference quantization offset of each color space, and using each color space. The color difference is quantized and the quantized coefficient image is inverse quantized.

The video encoding program of the present invention implements a video encoding method for selecting a color space of a prediction error signal from a plurality of color spaces in a coding block unit, and the video encoding program is characterized in that the computer performs the following processing: export processing Deriving a color difference quantization offset for each color space; and inverse quantization processing to inverse quantize the quantized coefficient image using the color difference quantization offset of each color space.

The video decoding program of the present invention implements a video decoding method for selecting a color space of a prediction error signal from a plurality of color spaces in a coding block unit, and the video decoding program is characterized in that the computer performs the following processing: export processing Deriving a color difference quantization offset for each color space; and inverse quantization processing to inverse quantize the quantized coefficient image using the color difference quantization offset of each color space. [Effects of the Invention]

According to the present invention, the subjective image quality improvement effect can be not impaired.

[Preferred Embodiment of the Invention] [Embodiment 1]

Fig. 1 is a block diagram showing a first embodiment of a video encoding apparatus. The video encoding apparatus will be described with reference to FIG. 1. The video encoding apparatus outputs a bit stream by using each frame of the digitized image as an input image.

As shown in FIG. 1, the video encoding apparatus of the first embodiment includes a switch 101, a color space converter 102, a switcher 103, a frequency conversion/quantizer 104, and inverse quantization, similarly to the general video encoding apparatus shown in FIG. The inverse frequency converter 105, the switch 106, the inverse color space converter 107, the switch 108, the buffer 109, the predictor 110, the prediction parameter determiner 111, the entropy encoder 112, the subtractor 115, and the adder 116.

As shown in FIG. 1, the video encoding device further includes an adaptive color difference quantization offset exporter 121 and a switcher 122.

Switch 101, color space converter 102, switch 103, frequency conversion/quantizer 104, inverse quantization/inverse frequency converter 105, switch 106, inverse color space converter 107, switch 108, buffer 109, prediction The controller 110, the subtractor 115, and the adder 116 operate in the same manner as those shown in FIG. 18. Therefore, the following mainly explains the operation of the adaptive color difference quantization offset derivation unit 121 and the switch 122, and the quantization quantization bias. The operation of the prediction parameter decider 111 and the entropy encoder 112 of the shifted transmission. Further, the adaptive color difference quantization offset derivation unit 121 inputs the color difference quantization offset for the RGB space and the color difference quantization offset for the YCoCr space.

Fig. 2 is a flow chart showing the processing related to the transmission of the color difference quantization offset.

The video encoding device transmits information indicating whether or not to implement the residual domain adaptive color conversion with adaptive_color_trans_flag. In addition, in the case of performing residual-domain adaptive color conversion, the video encoding apparatus transmits information indicating the color space of the block by cu_residual_csc_flag.

In the case where the residual domain adaptive color conversion is not implemented, the entropy encoder 112 transmits adaptive_color_trans_flag=0, but the adaptive color difference quantization offset derivative 121 derives the color difference quantization offset for the RGB space (already input to The color difference quantization offset for the RGB space of the adaptive color difference quantization offset derivation unit 121 is transmitted in the following syntax (steps S101, S102). In the case where the residual domain adaptive color conversion is implemented, the entropy encoder 112 sets adaptive_color_trans_flag=1. Further, when compression is performed in the RGB space, the entropy encoder 112 transmits the color difference quantization offset for the RGB space derived by the adaptive color difference quantization offset derivation unit 121 by the following syntax (steps S103 and S104).・Picture unit: pps_cb_qp_offset/pps_cr_qp_offset/slice_qp_delta_cb/slice_qp_delta_cr ・Slice unit: slice_qp_delta_cb/slice_qp_delta_cr

When compression is performed in the YCoCr space, the entropy encoder 112 transmits the chroma quantization offset for the YCoCr space derived by the adaptive color difference quantization offset derivation unit 121 by the following syntax (steps S103, S105).・Picture unit: alt_pps_cb_qp_offset/alt_pps_cr_qp_offset/alt_slice_qp_delta_cb/alt_slice_qp_delta_cr ・Slice unit: alt_slice_qp_delta_cb/alt_slice_qp_delta_cr

Further, in the case where the residual domain adaptive color conversion is performed, when compression is performed in the YCoCr space (when compression is not performed in the RGB space), the entropy encoder 112 transmits cu_residual_csc_flag=1. The adaptive color difference quantization offset derivation unit 121 outputs the color difference quantization offset (first color difference quantization offset and second color difference quantization offset) for the derived YCoCr space to the switch 122.

When compression is performed in the RGB space, the entropy encoder 112 transmits cu_residual_csc_flag=0. The adaptive color difference quantization offset derivation unit 121 outputs the color difference quantization offset (first color difference quantization offset and second color difference quantization offset) for the derived RGB space to the switch 122.

Further, the adaptive color difference quantization offset exporter 121 recognizes the compression in the RGB space or the compression in the YCoCr space in accordance with the cu_residual_csc_flag.

Further, the frequency conversion/quantizer 104 adjusts the quantization parameter using the color difference quantization offset determined by the prediction parameter decider 111.

The prediction parameter determiner 111 memorizes, for example, the color difference quantization offset value for the RGB space and the color difference quantization offset value for the YCoCr space, and appropriately quantizes the quantization offset value for the RGB space or the color difference for the YCoCr space. The shift value is supplied to the frequency conversion/quantizer 104. In this case, the color difference quantization offset value for the RGB space and the color difference quantization offset value for the YCoCr space are included in the prediction parameter supplied to the entropy encoder 112. The entropy encoder 112 signals the color difference quantization offset value for the RGB space and the color difference quantization offset value for the YCoCr space.

In this case, the video encoding device explicitly emits the color difference quantization offset. Moreover, the color difference quantization offset value is transmitted.

Further, a more detailed operation of the adaptive color difference quantization offset exporter 121 will be described in detail in the second embodiment.

The operation of the video encoding device other than the above operation is the same as that of the video encoding device shown in FIG. [Embodiment 2]

3 is a block diagram showing an embodiment of a video decoding device that decodes a bit stream and obtains a decoded image, wherein the bit stream is transmitted by a color difference quantization offset. Output by the encoding device. The configuration of the video decoding device of the second embodiment will be described with reference to Fig. 3 .

As shown in FIG. 3, the video decoding apparatus of this embodiment includes an entropy decoder 212, an inverse quantization/inverse frequency converter 205, a switch 206, and an inverse color space converter 207, similarly to the general video decoding apparatus shown in FIG. Switch 208, buffer 209, predictor 210, and adder 216.

As shown in FIG. 3, the video decoding device further includes an adaptive color difference quantization offset exporter 221 and a switch 222.

The inverse quantization/inverse frequency converter 205, the switch 206, the inverse color space converter 207, the switch 208, the buffer 209, the predictor 210, and the adder 216 operate in the same manner as those shown in Fig. 19, so The operation of the adaptive color difference quantization offset derivation unit 221 and the switch 222 and the operation of the entropy decoder 212 regarding the derivation of the color difference quantization offset are mainly described.

Figure 4 is a flow chart showing the processing associated with the derivation of the color difference quantization offset.

The entropy decoder 212 interprets the adaptive_color_trans_flag=1 (indicating that the residual-domain adaptive color conversion will be implemented) from the bit stream (step S201), and interprets cu_residual_csc_flag=1 (indicating that data compression has been performed in the YCoCr space) (Step S202), the adaptive color difference quantization offset derivation unit 221 derives the color difference quantization offset for the YCoCr space (step S204). When the entropy decoder 212 interprets cu_residual_csc_flag=0 (indicating that data compression has been performed in the RGB space) (step S202), the adaptive chroma quantization offset derivation unit 221 derives the chroma quantization offset for the RGB space (step S203).

The adaptive color difference quantization offset derivation unit 221 derives the color difference quantization offset (first color difference quantization offset qPi _Cb and second color difference quantization offset qPi _Cr ) for the RGB space as follows. qPi _Cb = Clip3( -QpBdOffset _C , 57, Qp _Y + pps_cb_qp_offset + slice_cb_qp_offset + CuQpOffset _Cb ) qPi _Cr = Clip3( -QpBdOffset _C , 57, Qp _Y + pps_cr_qp_offset + slice_cr_qp_offset + CuQpOffset _Cr ) (2)

In equation (2), Clip3(x, y, z) is a function that clips the input value z to the range of [x, y]. Qp _Y is a quantization parameter of the first color component, a chroma quantization offset of each block of the CuQpOffset _Cb- based second color component, and a chroma quantization offset of each block of the CuQpOffset _Cr- based third color component. In addition, although it is represented by qPi _Cb and qPi _Cr , in the case of the RGB space of the first color component system G component, the second color component system B component, and the third color component system R component, qPi _Cb corresponds to the B component. The color difference quantization offset, qPi _{Cr is} equivalent to the color difference quantization offset of the R component.

The adaptive color difference quantization offset derivation unit 221 derives the color difference quantization offset (first color difference quantization offset qPi _Cb and second color difference quantization offset qPi _Cr ) for the YCoCr space as shown in the following equation (3). qPi _Cb = Clip3( -QpBdOffset _C , 57, Qp _Y + alt_pps_cb_qp_offset + alt_slice_cb_qp_offset + CuQpOffset _Cb ) qPi _Cr = Clip3( -QpBdOffset _C , 57, Qp _Y + alt_pps_cr_qp_offset + alt_slice_cr_qp_offset + CuQpOffset _Cr ) (3)

Further, the quantization parameters (Qp' _Cb and Qp' _Cr ) are calculated by the following formula (4). Qp' _Cb = qP _Cb + QpBdOffset _C Qp' _Cr = qP _Cr + QpBdOffset _C (4)

A specific example of the derivation program of the chroma quantization offset is shown below. In the following description, the portions enclosed by double quotation marks are characteristic portions of the present embodiment. - "If cu_residual_csc_flag is equal to 0", the variables qP _Cb and qP _{Cr are} derived as follows: qPi _Cb = Clip3( -QpBdOffset _C , 57, Qp _Y + pps_cb_qp_offset + slice_cb_qp_offset + CuQpOffset _Cb ) qPi _Cr = Clip3( -QpBdOffset _C , 57 , Qp _Y + pps_cr_qp_offset + slice_cr_qp_offset + CuQpOffset _Cr ) - "Otherwise (cu_residual_csc_flag is equal to 1), the variables qP _Cb and qP _{Cr are} derived as follows: 』 『qPi _Cb = Clip3( -QpBdOffset _C , 57, Qp _Y + alt_pps_cb_qp_offset + alt_slice_cb_qp_offset + CuQpOffset _Cb )』 『qPi _Cr = Clip3( -QpBdOffset _C , 57, Qp _Y + alt_pps_cr_qp_offset + alt_slice_cr_qp_offset + CuQpOffset _Cr )』 - If ChromaArrayType is equal to 1, then based on the index qPi is equal to qPi _Cb and qPi _Cr , respectively, and The variables qP _Cb and qP _{Cr are} set equal to the value of Qp _C specified by the predetermined table. - Otherwise, based on the index qPi being equal to qPi _Cb and qPi _Cr , respectively, the variables qP _Cb and qP _{Cr are} set equal to Min(qPi, 51). The color difference quantization parameters Qp' _Cb and Qp' _{Cr of the} -Cb component and the Cr component are derived as follows: Qp' _Cb = qP _Cb + QpBdOffset _C Qp' _Cr = qP _Cr + QpBdOffset _C

The inverse quantization/inverse frequency converter 205 inversely quantizes the input quantized coefficient image as a coefficient image output, and increases or decreases the quantization parameter according to the color difference quantization offset of the adaptive color difference quantization offset derivation unit 221. [Embodiment 3]

Next, a video encoding apparatus according to a third embodiment will be described. FIG. 5 is an explanatory diagram showing an example of a syntax for transmitting alt_pps_cb_qp_offset and alt_pps_cr_qp_offset (an improvement of 7.3.2.3.2 Picture parameter set range extension syntax described in Non-Patent Document 1). In Fig. 5, the italicized font display shows the features of this embodiment.

FIG. 6 and FIG. 7 are explanatory diagrams showing an example of a syntax for transmitting alt_slice_qp_delta_cb and alt_slice_qp_delta_cr (an improvement of the 7.3.6.1 General slice segment header syntax described in Non-Patent Document 1). In Figs. 6 and 7, the italicized font display shows the features of this embodiment.

The configuration of the video encoding apparatus of this embodiment is the same as that of the configuration shown in FIG. 1. Among the video encoding devices, the entropy encoder 112 determines the information of the color difference quantization offset for the RGB space (for example, an index or a color difference that specifies a data table in which the video decoding device holds the color difference quantization offset). The quantized offset value is transmitted to the video decoding device.

In the case of performing data compression in the YCoCr space, the entropy encoder 112 can determine the information of the color difference quantization offset for the YCoCr space (for example, the color difference quantization offset value itself) using the syntax illustrated by FIG. 5, FIG. 6, and FIG. ) to send a message. [Embodiment 4]

Next, a video decoding device according to a fourth embodiment will be described. The video decoding device of this embodiment corresponds to the video encoding device of the third embodiment. The configuration of the video decoding device of this embodiment is the same as that of the configuration shown in FIG.

Among the video decoding devices, the entropy decoder 212 interprets the data compression performed in the YCoCr space by the syntax shown in FIGS. 5, 6, and 7, and the adaptive color difference quantization offset exporter 221 In the same manner as in the second embodiment, the color difference quantization offset is derived.

Further, among the video encoding devices, the adaptive color difference quantization offset derivation unit 121 operates in the same manner as the adaptive color difference quantization offset derivation unit 221. [Embodiment 5]

Next, a video encoding apparatus according to a fifth embodiment will be described. 8 is an explanatory diagram showing an example of a syntax for additionally transmitting cb_qp_offset_list [i] and cr_qp_offset_list [i] for the YCoCr space (an improvement of 7.3.2.3.2 Picture parameter set range extension syntax described in Non-Patent Document 1). . In Fig. 8, the italicized word display indicates the feature of the present embodiment (that is, the size of the cb_qp_offset_list/cr_qp_offset_list (the range of chroma_qp_offset_list_len_minus1) is expanded in response to the value of adaptive_color_trans_flag). In the video encoding apparatus according to the present embodiment, the value of the cu_chroma_qp_offset_idx syntax transmitted in block units in accordance with the value of the cu_residual_csc_flag syntax can be adjusted, thereby switching the quantization offset for the RGB space and the YCoCr space in units of blocks. .

The configuration of the video encoding apparatus of this embodiment is the same as that of the configuration shown in FIG. 1. Among the video encoding devices, the entropy encoder 112 can determine the information of the color difference quantization offset for the RGB space (for example, the cu_chroma_qp_offset_idx syntax, which specifies the data table set by the video decoding device to set the color difference quantization offset. The indicator is transmitted to the video decoding device.

In the present embodiment, among the video encoding devices, the entropy encoder 112 can determine the information of the color difference quantization offset for the YCoCr space (for example, the cu_chroma_qp_offset_idx syntax, which is set by the video decoding device to set the color difference quantization offset. The data table is transmitted to the video decoding device with the specified indicator). The video decoding apparatus according to the present embodiment can switch the color difference quantization offset for the RGB space and the YCoCr space in units of blocks based on the value of the cu_chroma_qp_offset_idx syntax that has been transmitted in block units in accordance with the value of the cu_residual_csc_flag syntax.

Further, in Fig. 8, the italicized word display positions (cb_qp_offset_list[i] and cr_qp_offset_list[i] correspond to the color difference quantization offset for the YCoCr space described above. [Embodiment 6]

Next, a video decoding device according to a sixth embodiment will be described. The video decoding device of this embodiment corresponds to the video encoding device of the fifth embodiment. The configuration of the video decoding device of this embodiment is the same as that of the configuration shown in FIG.

Among the video decoding apparatuses, the entropy decoder 212 reads out the data compression using the YCoCr space by the syntax shown by the example shown in FIG. 8, for example, reading the excellent difference quantization offset by the data table specified by the index, and adaptability. The color difference quantization offset derivation unit 221 calculates the color difference quantization parameter in the same manner as in the case of the second embodiment.

Further, among the video encoding devices, the adaptive color difference quantization offset derivation unit 121 operates in the same manner as the adaptive color difference quantization offset derivation unit 221. [Embodiment 7]

Next, a video encoding apparatus according to a seventh embodiment will be described. FIG. 9 is an explanatory diagram showing an example of a syntax for transmitting alt_cb_qp_offset_list[i] and alt_cr_qp_offset_list[i] for the YCoCr space (an improvement of 7.3.2.3.2 Picture parameter set range extension syntax described in Non-Patent Document 1). In Fig. 9, the italicized font display shows the features of this embodiment.

In the seventh embodiment, as will be described later, the interpretation of the value of the cu_chroma_qp_offset_idx syntax may be changed in accordance with the value of the cu_residual_csc_flag syntax as compared with the fifth embodiment, so that the bit of the transmitted cu_chroma_qp_offset_idx syntax can be saved for each block. number. For example, in the seventh embodiment, even if cu_chroma_qp_offset_idx=0, cb_qp_offset_list[0] and cr_qp_offset_list[0] for RGB are derived in the case of cu_residual_csc_flag=0, and alt_cb_qp_offset_list for YCoCr is derived in the case of cu_residual_csc_flag=1. 0] and alt_cr_qp_offset_list [0] . On the other hand, in the fifth embodiment, cu_chroma_qp_offset_idx=0 derives cb_qp_offset_list[0] and cr_qp_offset_list[0] for RGB. Therefore, in the fifth embodiment, when the size of the list is 4 (in the case of chroma_qp_offset_list_len_minus1 is 3), in order to derive cb_qp_offset_list[4] and alt_cr_qp_offset_list[4] for YCoCr, cu_chroma_qp_offset_idx=4 must be transmitted.

The configuration of the video encoding apparatus of this embodiment is the same as that of the configuration shown in FIG. 1. In the video encoding device, the entropy encoder 112 transmits information that can determine the color difference quantization offset for the RGB space (for example, an index specifying a data table set by the video decoding device and having the color difference quantization offset) to the video. Decoding device.

In the present embodiment, in the video encoding apparatus, the entropy encoder 112 specifies information for determining the color difference quantization offset for the YCoCr space (for example, specifying a data table in which the video decoding device holds the color difference quantization offset). The indicator is transmitted to the video decoding device. [Embodiment 8]

Next, a video decoding device according to an eighth embodiment will be described. The video decoding device of this embodiment corresponds to the video encoding device of the seventh embodiment. The configuration of the video decoding device of this embodiment is the same as that of the configuration shown in FIG.

Among the video decoding apparatuses, the entropy decoder 212 reads out the data compression performed by the YCoCr space by the syntax shown in FIG. 9, for example, reading the excellent difference quantization offset by the data table specified by the index, and adaptive color difference. The quantization offset derivation unit 221 calculates the color difference quantization parameter in the same manner as in the case of the second embodiment.

Further, among the video encoding devices, the adaptive color difference quantization offset derivation unit 121 operates in the same manner as the adaptive color difference quantization offset derivation unit 221.

A specific example of the derivation program of the chroma quantization offset is shown below. In the following description, the portion enclosed by double quotation marks is a technical feature portion of the present embodiment. When cu_chroma_qp_offset_idx exists, the indicator points to cb_qp_offset_list[ ] and cr_qp_offset_list [ ], or the alt_cb_qp_offset_list [ ] and alt_cr_qp_offset_list [ ], and this cu_chroma_qp_offset_idx is used to determine the values of CuQpOffsetCb and CuQpOffsetCr. When cu_chroma_qp_offset_idx exists, the value of cu_chroma_qp_offset_idx shall be 0 to the range of chroma_qp_offset_list_len_minus1 (including both ends). When cu_chroma_qp_offset_idx does not exist, the value of cu_chroma_qp_offset_idx is inferred to be equal to zero. When cu_chroma_qp_offset_flag is present, the following is performed: - The variable IsCuChromaQpOffsetCoded is set to 1. - These variables CuQpOffsetCb and CuQpOffsetCr derived as follows: - If cu_chroma_qp_offset_flag equal to 1 and "cu_residual_csc_flag equal to 0", perform the following: CuQpOffsetCb = cb_qp_offset_list [cu_chroma_qp_offset_idx] CuQpOffsetCr = cr_qp_offset_list [cu_chroma_qp_offset_idx] - "Otherwise, if cu_chroma_qp_offset_flag equal to 1 and equal cu_residual_csc_flag 1, the implementation is as follows: 』 『CuQpOffsetCb = alt_cb_qp_offset_list [cu_chroma_qp_offset_idx] 』 "CuQpOffsetCr = alt_cr_qp_offset_list [cu_chroma_qp_offset_idx]" - Otherwise (cu_chroma_qp_offset_flag is equal to 0), CuQpOffsetCb and CuQpOffsetC are also equal to 0. [Embodiment 9]

In each of the above embodiments, the video encoding device explicitly transmits the color difference quantization offset, but may also transmit the color space of the prediction error signal in block units without signaling the color difference. Move to send a message. This description is referred to as implicitly signaling the color difference quantization offset.

In the case where the video encoding device implicitly transmits the color difference quantization offset, the entropy encoder transmits adaptive_color_trans_flag=1, for example, cu_residual_csc_flag is transmitted in block units, but the color difference quantization offset value is not determined. The information is sent to the news.

In the video decoding apparatus, when the entropy decoder interprets adaptive_color_trans_flag=1 from the bit stream, and interprets cu_residual_csc_flag=0 (indicating that data compression has been performed in RGB space), the adaptive color difference quantization offset exporter 221 The value of the color difference quantization offset for the RGB space previously stored in the video decoding device is read. Further, when cu_residual_csc_flag=1 is interpreted (indicating that data compression has been performed in the YCoCr space), the adaptive color difference quantization offset derivation unit 221 calculates the color difference quantization offset for the YCoCr space from the color difference quantization offset value for the RGB space stored in advance. value.

The color difference quantization offset for the RGB space has a certain degree of correlation with the color difference quantization offset for the YCoCr space, that is, the color difference quantization offset for calculating the YCoCr space by the color difference quantization offset for the RGB space can be determined. In the calculation formula, the adaptive color difference quantization offset derivation unit 221 can derive the color difference quantization offset for the YCoCr space by such an equation.

That is, the video decoding device implicitly derives the color difference quantization offset.

Further, among the video encoding devices, the adaptive color difference quantization offset derivation unit 121 operates in the same manner as the adaptive color difference quantization offset derivation unit 221.

Further, when the video encoding device implicitly transmits the color difference quantization offset, the amount of data to be transmitted can be reduced.

Further, when the video encoding device and the video decoding device implicitly derive the color difference quantization offset, the color difference quantization offset for one color space may be set to zero. For example, when cu_residual_csc_flag=0 (indicating that data compression has been performed in RGB space), the adaptive color difference quantization offset exporter 221 reads the 色0 color difference quantization offset for the RGB space previously stored in the video decoding device. value. Further, when cu_residual_csc_flag=1 is interpreted (indicating that data compression has been performed in the YCoCr space), the adaptive color difference quantization offset exporter 221 calculates YCoCr from pps_cb_qp_offset/pps_cr_qp_offset/slice_qp_delta_cb transmitted in picture units and slice_qp_delta_cb/slice_qp_delta_cr transmitted in slice units. The color difference quantization offset for space is 値.

A specific example of the derivation program of the chroma quantization offset is shown below. In the following description, the portion enclosed by double quotation marks is a characteristic portion in the present embodiment. - "If adaptive_color_trans_flag is equal to 0", the variables qP _Cb and qP _{Cr are} derived as follows: qPi _Cb = Clip3( -QpBdOffset _C , 57, Qp _Y + pps_cb_qp_offset + slice_cb_qp_offset + CuQpOffset _Cb ) qPi _Cr = Clip3( -QpBdOffset _C , 57 , Qp _Y + pps_cr_qp_offset + slice_cr_qp_offset + CuQpOffset _Cr ) - "Otherwise, if adaptive_color_trans_flag is equal to 1, and cu_residual_csc_flag is equal to 0", the variables qP _Cb and qP _{Cr are} derived as follows: qPi _Cb = Clip3( -QpBdOffset _C , 57, Qp _Y + CuQpOffset _Cb ) qPi _Cr = Clip3( -QpBdOffset _C , 57, Qp _Y + CuQpOffset _Cr ) - "Otherwise (daptive_color_trans_flag is equal to 1 and cu_residual_csc_flag is equal to 1), the variables qP _Cb and qP _{Cr are} derived as follows: 』 『qPi _Cb = Clip3( -QpBdOffset _C , 57, Qp _Y + pps_cb_qp_offset + slice_cb_qp_offset + CuQpOffset _Cb )』 『qPi _Cr = Clip3( -QpBdOffset _C , 57, Qp _Y + pps_cr_qp_offset + slice_cr_qp_offset + CuQpOffset _Cr )』 - If ChromaArrayType is equal to 1, then Based on the index qPi being equal to qPi _Cb and qPi _Cr , respectively, the variables qP _Cb and qP _Cr are equal to The value of Qp _C specified in the predetermined table. - Otherwise, based on the index qPi being equal to qPi _Cb and qPi _Cr , respectively, the variables qP _Cb and qP _{Cr are} set equal to Min(qPi, 51). The color difference quantization parameters Qp' _Cb and Qp' _{Cr of the} -Cb component and the Cr component are derived as follows: Qp' _Cb = qP _Cb + QpBdOffset _C Qp' _Cr = qP _Cr + QpBdOffset _C

In each of the above embodiments, the RGB space and the YCoCr space are exemplified as two color spaces. However, even if one of the two color spaces or both are other color spaces, the embodiments of the above embodiments can be applied. Further, in the above embodiment, the first color component is G in the RGB space, the second color component is B, and the third color component is R (refer to FIG. 20), but the color signal distribution method for each color component is not In this case, any color signal can be assigned to each color component.

Further, in each of the above embodiments, the video encoding device and the video decoding device process two color spaces, but may process three or more color spaces.

Further, each of the above embodiments may be configured as a hardware, and may be realized by a computer program.

The information processing system shown in FIG. 10 includes a processor 1001, a program memory 1002, a memory medium 1003 for storing video data, and a memory medium 1004 for storing a bit stream. The memory medium 1003 and the memory medium 1004 may be individual memory media or may be memory regions formed by the same memory medium. As far as the memory medium is concerned, a magnetic memory medium such as a hard disk can be used.

In the information processing system shown in FIG. 10, the program memory 1002 stores a program for realizing the functions of the respective blocks (excluding the blocks of the buffer) shown in each of FIGS. 1 and 3. Further, the processor 1001 performs processing in accordance with the program stored in the program memory 1002, thereby realizing the functions of the video encoding device or the video decoding device shown in each of FIGS. 1 and 3.

Figure 11 is a block diagram showing the main part of the video encoding apparatus. As shown in FIG. 11, the video encoding device 301 includes an adaptive color difference quantization offset deriving unit 311 (for example, equivalent to the adaptive color difference quantization offset exporter 121 shown in FIG. 1), and derives each color. a color difference quantization offset of the space; and an inverse quantization unit 312 (for example, equivalent to the inverse quantization/inverse frequency converter 105 shown in FIG. 1), using the color difference quantization offset of each color space to quantize the coefficient The image is inverse quantified.

Fig. 12 is a block diagram showing the main part of another example of the video encoding device. As shown in FIG. 12, the video encoding device 302 further includes a color space selection notifying portion 313 for transmitting the color space of the prediction error signal in units of blocks (for example, equivalent to FIG. 1 Entropy encoder 112).

Further, in the configuration shown in FIG. 12, the video encoding device 302 implicitly derives the color difference quantization in the case where the video encoding device 302 does not include a mechanism for signaling the information of the quantized offset value of each color space. Offset.

Figure 13 is a block diagram showing the main part of another example of the video encoding apparatus. As shown in FIG. 13, the video encoding device 303 further includes a quantization offset information transmitting unit 314 (for example, equivalent to the entropy encoder 112 shown in FIG. 1), which can quantize the color difference of each color space. The information of the offset value is sent. The information of the color difference quantization offset value may be determined, for example, the color difference quantization offset value itself or an index specifying a data table in which the video decoding device holds the color difference quantization offset.

Fig. 14 is a block diagram showing the main part of the video decoding device. As shown in FIG. 14, the video decoding device 401 includes an adaptive color difference quantization offset deriving unit 411 (for example, equivalent to the adaptive color difference quantization offset exporter 221 shown in FIG. 3), and derives each color. The color difference quantization offset of the space; and the inverse quantization unit 412 (which, as an example, corresponds to the inverse quantization/inverse frequency converter 205 shown in FIG. 3), uses the color difference quantization offset of each color space to apply the quantized coefficient image Anti-quantization.

Fig. 15 is a block diagram showing the main part of another example of the video decoding device. As shown in FIG. 15, the video decoding device 402 further includes a color space selection and interpretation unit 413 (which, as an example, corresponds to the entropy decoder 212 shown in FIG. 3), streams the received bit stream into block units. The purpose of selecting the color space of the prediction error signal is interpreted.

Further, in the configuration shown in FIG. 15, in the case where the video decoding device 402 does not include a mechanism for interpreting information capable of determining the color difference quantization offset value of each color space, the video decoding device 402 implicitly derives the color difference. Quantize the offset.

Fig. 16 is a block diagram showing the main part of still another example of the video decoding device. As shown in FIG. 16, the video decoding device 403 further includes a chroma quantization offset interpretation unit 414 (corresponding to the entropy decoder 212 shown in FIG. 3 as an example), based on the information decoded from the received bit stream. The color difference quantization offset value of each color space is determined.

The present invention has been described above with reference to the embodiments and examples, but the invention is not limited to the embodiments and examples described above. Various changes that can be understood by those of ordinary skill can be made in the scope of the invention of the present invention.

The priority of Japanese Patent Application No. 2014-214959, filed on Oct. 22, 2014, is hereby incorporated by reference.

101‧‧‧Switch
102‧‧‧Color Space Converter
103‧‧‧Switch
104‧‧‧Frequency conversion/quantizer
105‧‧‧Anti-quantization/inverse frequency converter
106‧‧‧Switcher
107‧‧‧Anti-color space converter
108‧‧‧Switcher
109‧‧‧buffer
110‧‧‧ predictor
111‧‧‧Predictive Parameter Determinator
112‧‧‧Entropy encoder
115‧‧‧Subtractor
116‧‧‧Adder
121‧‧‧Adaptive color difference quantization offset exporter
122‧‧‧Switcher
205‧‧‧Anti-quantization/inverse frequency converter
206‧‧‧Switcher
207‧‧‧Anti-color space converter
208‧‧‧Switch
209‧‧‧buffer
210‧‧‧ predictor
212‧‧‧ Entropy decoder
216‧‧‧Adder
221‧‧‧Adaptive color difference quantization offset exporter
222‧‧‧Switch
301, 302, 303‧‧ ‧ video coding device
311‧‧‧Adaptive color difference quantization offset derivation unit
312‧‧‧Anti-quantization department
313‧‧‧Color Space Selection Notification Department
314‧‧‧Quantitative Offset Information Transmission Department
401, 402, 403‧‧ ‧ video decoding device
411‧‧‧Adaptive color difference quantization offset derivation unit
412‧‧‧Anti-quantization department
413‧‧‧Color Space Selection Interpretation Department
414‧‧‧Color Difference Quantization Offset Interpretation Department
1001‧‧‧ processor
1002‧‧‧Program memory
1003‧‧‧Memory Media
1004‧‧‧Memory Media
S101～S105‧‧‧Steps
S201～S204‧‧‧Steps

Fig. 1 is a block diagram showing an embodiment of a video encoding apparatus. Fig. 2 is a flow chart showing the processing related to the transmission of the color difference quantization offset. Fig. 3 is a block diagram showing an embodiment of a video decoding device. Figure 4 is a flow chart showing the processing associated with the derivation of the color difference quantization offset. Fig. 5 is an explanatory diagram showing an example of a syntax for transmitting alt_pps_cb_qp_offset and alt_pps_cr_qp_offset. Fig. 6 is an explanatory diagram showing an example of a syntax for transmitting alt_slice_qp_delta_cb and alt_slice_qp_delta_cr. Fig. 7 is an explanatory diagram showing an example of a syntax for transmitting alt_slice_qp_delta_cb and alt_slice_qp_delta_cr. Fig. 8 is an explanatory diagram showing an example of a syntax for transmitting cb_qp_offset_list [i] and cr_qp_offset_list [i]. Fig. 9 is an explanatory diagram showing an example of a syntax for transmitting alt_cb_qp_offset_list [i] and alt_cr_qp_offset_list [i]. Fig. 10 is a block diagram showing an example of the configuration of an information processing system that can realize the functions of the video encoding device and the video decoding device. Figure 11 is a block diagram showing the main part of the video encoding apparatus. Fig. 12 is a block diagram showing the main part of another example of the video encoding apparatus. Fig. 13 is a block diagram showing the main part of still another example of the video encoding apparatus. Fig. 14 is a block diagram showing the main part of the video decoding device. Fig. 15 is a block diagram showing the main part of another example of the video decoding device. Fig. 16 is a block diagram showing the main part of still another example of the video decoding device. Fig. 17 is an explanatory diagram showing an example of residual color adaptive color conversion. Fig. 18 is a block diagram showing the configuration of a general video encoding device. Fig. 19 is a block diagram showing the configuration of a general video decoding device. Fig. 20 is an explanatory diagram showing an example of use of the color difference quantization offset.

303‧‧‧Video coding device

311‧‧‧Adaptive color difference quantization offset derivation unit

312‧‧‧Anti-quantization department

314‧‧‧Quantitative Offset Information Transmission Department

Claims (18)

A video encoding device can select a color space of a prediction error signal from a plurality of color spaces in a coding block unit. The video encoding device is characterized by: an adaptive color difference quantization offset deriving mechanism that derives each color space. The color difference quantization offset; and an inverse quantization mechanism that inverse quantizes the quantized coefficient image using the color difference quantization offset of each color space. The video encoding device of claim 1, further comprising: a color space selection notification mechanism that signals the color space of the prediction error signal in a block unit to be signaled. The video encoding device of claim 2, further comprising: a color difference quantization offset information transmission mechanism that transmits information that can determine a color difference quantization offset value of each color space. A video decoding device can select a color space of a prediction error signal from a plurality of color spaces in a coding block unit, and the video decoding device is characterized by: an adaptive color difference quantization offset deriving mechanism that derives each color space The color difference quantization offset; and an inverse quantization mechanism that inverse quantizes the quantized coefficient image using the color difference quantization offset of each color space. The video decoding device of claim 4, further comprising: a color space selection and interpretation mechanism for interpreting the color space of the prediction error signal from the received bit stream in block units. The video decoding device of claim 5, further comprising: a color difference quantization offset interpretation mechanism that determines a quantization offset value for each color space based on the information interpreted from the received bit stream. A video encoding method, which can select a color space of a prediction error signal from a plurality of color spaces in a coding block unit, the video encoding method is characterized by: deriving a quantization offset of each color space, and using each color space The color difference is quantized and the quantized coefficient image is inverse quantized. For example, in the video encoding method of claim 7, wherein the color space of the prediction error signal is selected in block units to be transmitted. For example, the video encoding method of claim 8 is characterized in that information for determining the color difference quantization offset value of each color space is transmitted. A video decoding method, which can select a color space of a prediction error signal from a plurality of color spaces in a coding block unit, the video decoding method is characterized by: deriving a quantization offset of each color space, and using each color space The color difference is quantized and the quantized coefficient image is inverse quantized. The video decoding method of claim 10, wherein the color space of the prediction error signal is selected from the received bit stream in block units for interpretation. The video decoding method of claim 11, wherein the color difference quantization offset value of each color space is determined based on the information interpreted from the received bit stream. A video encoding program that implements a video encoding method that selects a color space of a prediction error signal from a plurality of color spaces in a coding block unit, and the video encoding program is used to cause a computer to perform the following processing: export processing, export each a color difference quantization offset of a color space; and an inverse quantization process that inverse quantizes the quantized coefficient image using the color difference quantization offset of each color space. For example, in the video coding program of claim 13, wherein the computer is executed: a transmission processing is performed, and the color space of the prediction error signal is selected in a block unit to be transmitted. For example, in the video encoding program of claim 14, wherein the computer is executed: another processing is performed, and information for determining the color difference quantization offset value of each color space is transmitted. A video decoding program, which implements a video decoding method for selecting a color space of a prediction error signal from a plurality of color spaces in a coding block unit, and the video decoding program is used to cause a computer to perform the following processing: export processing, export each a color difference quantization offset of a color space; and an inverse quantization process that inverse quantizes the quantized coefficient image using the color difference quantization offset of each color space. For example, in the video decoding program of claim 16, wherein the computer performs: the interpretation process, the color space of the prediction error signal is selected from the received bit stream in block units for interpretation. For example, the video decoding program of claim 17 wherein the computer executes: determining processing, determining the color difference quantization offset value of each color space based on the information interpreted from the received bit stream.