Video image processing method and device, and storage medium

A video image decoding method comprising:

• binarizing a chrominance prediction mode of an image block of a to be decoded image to obtain a bit string, the bit string including at least three adjacent bits, the to be decoded image being permitted to use at least one of a cross-component linear model (CCLM) or a regular intra-frame chrominance prediction mode, the CCLM including at least a first mode, a second mode, and a third mode, the regular intra-frame chrominance prediction mode being other intra-frame chrominance prediction modes except the CCLM, wherein:
• a first bit of the adjacent bits is used to indicate whether the CCLM is used, a second bit is used to indicate whether to use the first mode of the CCLM when the first bit indicates to use the CCLM, a third bit is used to indicate whether the second mode or the third mode of the CCLM is used when the second bit indicates that the first mode of the CCLM is not used, and the first bit indicates that the CCLM is used when a value of the first bit is 1;
• and
• using mutually independent probability models to respectively decode the first bit and the second bit.

A non-transitory computer-readable storage medium storing a bitstream generated by an encoding method comprising:

• binarizing a chrominance prediction mode of an image block of a to be encoded image to obtain a bit string, the bit string including at least three adjacent bits, the to be encoded image being permitted to use at least one of a cross-component linear model (CCLM) or a regular intra-frame chrominance prediction mode, the CCLM including at least a first mode, a second mode, and a third mode, the regular intra-frame chrominance prediction mode being other intra-frame chrominance prediction modes except the CCLM, wherein:
• a first bit of the adjacent bits is used to indicate whether the CCLM is used, a second bit is used to indicate whether to use the first mode of the CCLM when the first bit indicates to use the CCLM, a third bit is used to indicate whether the second mode or the third mode of the CCLM is used when the second bit indicates that the first mode of the CCLM is not used, and the first bit indicates that the CCLM is used when a value of the first bit is 1;
• and
• using mutually independent probability models to respectively encode the first bit and the second bit to generate the bitstream.