Image component prediction method and device, and computer storage medium

An encoder, comprising a processor and a memory configured to store a computer program capable of running on the processor, wherein the processor is configured to:

• acquire a first reference sample set corresponding to a colour component to be predicted of a coding block in a video picture;
• when a number of available samples in the first reference sample set is equal to 0, take a preset component value as a prediction value corresponding to the colour component to be predicted;
• and
• when a number of the available samples in the first reference sample set is greater than or equal to 4, process the first reference sample set to obtain a second reference sample set, wherein a number of available samples in the second reference sample set is less than or equal to a preset number;
• when the number of the available samples in the second reference sample set is equal to the preset number, determine a model parameter through the second reference sample set, wherein the model parameter is used to implement a prediction processing of the colour component to be predicted to obtain a prediction value corresponding to the colour component to be predicted.

A method for transmitting a bitstream, comprising:

• executing an encoding method to generate a bitstream;
• and transmitting the bitstream;
• wherein the encoding method comprises:
• acquiring a first reference sample set corresponding to a colour component to be predicted of a coding block in a video picture;
• when a number of available samples in the first reference sample set is equal to 0, taking a preset component value as a prediction value corresponding to the colour component to be predicted;
• and
• when a number of the available samples in the first reference sample set is greater than or equal to 4, processing the first reference sample set to obtain a second reference sample set, wherein a number of available samples in the second reference sample set is less than or equal to a preset number;
• when the number of the available samples in the second reference sample set is equal to the preset number, determining a model parameter through the second reference sample set, wherein the model parameter is used to implement a prediction processing of the colour component to be predicted to obtain a prediction value corresponding to the colour component to be predicted.