Intra-Frame Encoding Method, Intra-Frame Decoding Method, Encoder, and Decoder

An encoder, comprising:

• a memory comprising instructions;
• and
• a processor coupled to the memory, wherein the instructions cause the processor to be configured to:
• obtain reference pixel values of a current picture block;
• obtain a predicted value of a first-type pixel in the current picture block according to the reference pixel values of the current picture block using an intra-frame prediction algorithm, wherein the current picture block comprises the first-type pixel and a second-type pixel, and wherein the second-type pixel is a pixel in the current picture block except the first-type pixel;
• obtain residual values of the first-type pixel according to the predicted value of the first-type pixel and an original pixel value of the first-type pixel;
• obtain transform coefficients according to the residual values of the first-type pixel;
• quantize the transform coefficients to obtain quantized transform coefficients;
• reconstruct the first-type pixel according to the quantized transform coefficients and the predicted value of the first-type pixel to obtain a reconstructed value of the first-type pixel;
• and
• obtain a reconstructed value of the second-type pixel according to the reconstructed value of the first-type pixel using an interpolation method.

A decoder, comprising:

• a memory comprising instructions;
• and
• a processor coupled to the memory, wherein the instructions cause the processor to be configured to:
• obtain reference pixel values of a current picture block;
• obtain a predicted value of a first-type pixel in the current picture block according to the reference pixel values of the current picture block using an intra-frame prediction algorithm, wherein the current picture block comprises the first-type pixel and a second-type pixel, and wherein the second-type pixel is a pixel in the current picture block except the first-type pixel;
• dequantize quantized transform coefficients of the current picture block to obtain transform coefficients;
• inversely transform the transform coefficients to obtain reconstructed residual values of the first-type pixel;
• add the reconstructed residual values of the first-type pixel and the predicted value of the first-type pixel to obtain a reconstructed value of the first-type pixel;
• and
• obtain a reconstructed value of the second-type pixel according to the reconstructed value of the first-type pixel using an interpolation method.