METHOD AND DEVICE FOR DETERMINING THE VALUE OF A QUANTIZATION PARAMETER

摘要

The value of a quantization parameter for at least one second color component of an image or image portion is determined using a current color format among several possible color formats. The determination comprises the steps of selecting at least one function associated with a possible color format, and determining the value of the quantization parameter for the second color component by applying said at least one function to a value of an intermediate quantization parameter which is based on the value of the quantization parameter of the first color component of the image or image portion. The at least one function is selected independently from the current color format.

主权项

1. A method of encoding an image or an image portion comprising determining the value QPC of a quantization parameter for at least one chroma component of an image or image portion by using the following
function to obtain the value QPC from a value of an intermediate quantization parameter QPI both when the color format is 4:2:2 and when the color format is 4:4:4,ChromaArrayType >1QPI<51≧51QPC=QPI51 the intermediate quantization parameter QPI being based on the value of a quantization parameter of a luma component of the image or image portion; and using the determined value to encode the image or image portion.