Method and apparatus for encoding/decoding image in spatial domain for noise component

A video decoding apparatus, comprising:

• a decoder, implemented by a processor, configured to reconstruct coding domain information and an encoded residual block from a bitstream, wherein the coding domain information indicates whether a residual block has been encoded by a frequency domain coding or by a spatial domain coding, wherein
• the frequency domain coding is a coding mode for encoding the residual block into frequency-domain values, and
• the spatial domain coding is a coding mode for encoding the residual block into spatial-domain values;
• an inverse quantizer, implemented by a processor, configured to inversely quantize the encoded residual block;
• an inverse transformer, implemented by a processor, configured to inversely transform the inversely quantized residual block from the frequency domain into the spatial domain, based on the coding domain information, wherein
• (1) when the coding domain information indicates the frequency domain coding, the inverse transformer configured to
• inversely transform the inversely quantized residual block from the frequency domain into the spatial domain,
• (2) when the coding domain information indicates the spatial domain coding, the inverse transformer configured to
• skip a step of inversely transforming the inversely quantized residual block;
• a predictor, implemented by a processor, configured to generate a predicted block corresponding to the residual block;
• and
• an adder, implemented by a processor, configured to reconstruct a current block based on the coding domain information by
• (A) adding the predicted block to the inversely transformed residual block when the coding domain information indicates the frequency domain coding, and
• (B) adding the predicted block to the inversely quantized residual block when the coding domain information indicates the spatial domain coding.