A video decoder may determine, based on syntax elements in a bitstream that comprises an encoded representation of the video data, residual quantized samples of a block of the video data. Additionally, the video decoder may determine quantized residual values based on the residual quantized samples. After determining the quantized residual values, the video decoder may inverse quantize the quantized residual values. The video decoder may generate predicted values by performing intra prediction for the block using unfiltered samples from above or left block boundary samples. Furthermore, the video decoder may reconstruct original sample values of the block based on the inverse-quantized quantized residual values and the prediction values.

The disclosure proposes a method of fixed-rate line-based embedded video compression and an image processing apparatus using the same method. The method includes at least the following steps. A current encoding frame is received. Pixels in a current encoding frame are grouped on a line-by-line basis, and the grouped pixels are packed into pixel segments. Complexity information of a current pixel segment is calculated according to the pixels therein and neighboring pixels thereof. The current pixel segment is respectively encoded in a differential pulse-coding modulation (DPCM) mode and a truncation mode to generate a DPCM bitstream and a truncated bitstream according to a quantization parameter (QP). Either the DPCM bitstream or the truncated bitstream is selected and outputted according to the complexity information. An amount of bits used by the current pixel segment is feedback to calculate a new QP corresponding to a next pixel segment to be processed.

An image decoding method performed by a decoding device according to the present document comprises the steps of: acquiring a block-based delta pulse code modulation (BDPCM) flag for a current block; on the basis of the BDPCM flag indicating that BDPCM is applied to the current block, acquiring a BDPCM direction flag for the current block; and storing, as an intra-prediction mode of the current block, an intra-prediction mode of a prediction direction derived on the basis of the BDPCM direction flag.

An image decoding method performed by a decoding device according to the present document comprises the steps of: acquiring a block-based delta pulse code modulation (BDPCM) flag for a current block; on the basis of the BDPCM flag indicating that BDPCM is applied to the current block, acquiring a BDPCM direction flag for the current block; and storing, as an intra-prediction mode of the current block, an intra-prediction mode of a prediction direction derived on the basis of the BDPCM direction flag.

An image processing apparatus comprising, an acquiring unit configured to acquire an encoding target block having a plurality of groups each including a predetermined number of pixels, a deciding unit configured to decide for each group a quantization parameter used to quantize image data of the group and an encoding scheme so that a code length of the encoding target block does not exceed a predetermined value, and an encoding unit configured to generate encoded data by encoding image data of the encoding target block in accordance with the quantization parameters and the encoding schemes decided for the respective groups by the deciding unit.

The disclosure proposes a method of fixed-rate line-based embedded video compression and an image processing apparatus using the same method. The method includes at least the following steps. A current encoding frame is received. Pixels in a current encoding frame are grouped on a line-by-line basis, and the grouped pixels are packed into pixel segments. Complexity information of a current pixel segment is calculated according to the pixels therein and neighboring pixels thereof. The current pixel segment is respectively encoded in a differential pulse-coding modulation (DPCM) mode and a truncation mode to generate a DPCM bitstream and a truncated bitstream according to a quantization parameter (QP). Either the DPCM bitstream or the truncated bitstream is selected and outputted according to the complexity information. An amount of bits used by the current pixel segment is feedback to calculate a new QP corresponding to a next pixel segment to be processed.

An apparatus for encoding an image data includes a sub-pixel rendering unit and a first differential pulse code modulation (DPCM) processing unit. The sub-pixel rendering unit converts first image data of an RGB type to second image data of an RG-BG type. The DPCM processing unit generates first differential data including primary differential values corresponding to respective sub-pixels. To perform this operation, the DPCM processing unit calculates a gray value difference from a neighboring sub-pixel for each of the sub-pixels based on the second image data.

Disclosed are an image compression method and apparatus, and an intelligent terminal and a computer-readable storage medium. The method comprises: obtaining a target image, and determining reference pixel points corresponding to target pixel points; determining pixel difference values of the target pixel points and the reference pixel points corresponding to same; determining, according to the pixel difference values, point compression data corresponding to the target pixel points; and compressing the target pixel points according to the point compression data to obtain image compression data of the target image.