The quantization step δ can be set by the user. It can also be calculated using another parameter λ setting the compromise between compression and quality and entered by the user or the encoder. For example, the quantization step δ can correspond to the quantization step δ₁ or be determined similarly to it.

In a step E227, the coefficients of the quantized block R2_TQ are then transmitted in a coded manner. For example, the coding specified in the HEVC standard can be used.

In a known manner, the current block is decoded by dequantizing the coefficients of the quantized block R2_TQ, then applying the inverse transform to the dequantized coefficients to obtain the decoded prediction residue. The prediction P1 is then added to the decoded prediction residue in order to reconstruct the current block and obtain its decoded version X_rec. The decoded version X_rec of the current block can then be used later to spatially predict other neighbouring blocks of the image or to predict blocks of other images by inter-image prediction.

In a step E23, it is checked if the current block is the last block of the image to be processed by the coding method, taking into account the previously defined scanning order. If the current block is not the last block of the image to be processed, in a step E24, the subsequent block of the image to be processed is selected according to the previously defined scanning order of the image and the coding method proceeds to step E2, where the selected block becomes the current block to be processed.