Color space coding method and device

Abstract

The invention provides a color space coding method and device. The method comprises the following steps: acquiring linear colors of a plurality of color components of a first image in a first color space; converting the linear color of each color component into a nonlinear color according to a color mapping function; according to the quantization bit number corresponding to each color component, quantizing the nonlinear color of each color component to obtain a quantized image. In the plurality of color components, the quantization bit number corresponding to at least one color component is different from the quantization bit number corresponding to other color components. The total bit number is effectively reduced on the premise of not introducing quantitative stripes, and the storage space and the transmission bandwidth are saved.

Description

technical field [0001] The invention relates to the field of color coding, in particular to a color space coding method and equipment. Background technique [0002] Generally speaking, the camera captures the light signal from the external environment through the lens, and the image sensor converts the light signal into an electrical signal linear in light intensity. Generally, the camera captures image data in RAW format (referred to as RAW image data) through an image sensor (Sensor), and the RAW image data only contains one gray value on each pixel, and the gray value is red / green / blue / in a component. The RAW image data is processed by the demosaic module of the Image Signal Processor (ISP), and the demosaic module supplements the other two components for each pixel interpolation, thereby generating a native RGB format image data (referred to as native RGB image data). The original RGB image data is transformed into a certain color gamut space (such as BT.709, P3, BT...

AI Technical Summary

Problems solved by technology

[0004] In the above color coding, the quantization coding process of the OETF module is a mapping process from multi-color values ​​to single color values, and there is information loss. If the quantization coding is not appropriate, it will cause the loss of information visible to the human eye. It can be seen that quantization stripes (banding) appear on the image, such as figure 1 It shows a scene where linear color values ​​are gamma-corrected and quantized, and stripes visible to the human eye appear, which seriously affects the quality of the image

If you want to ensure that there are no streaks, you need to increase the number of quantization bits n, resulting in an increase in the amount of data and a waste of transmission bandwidth

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