JPEG (Joint Photographic Experts Group) image processing method and system

Abstract

The invention discloses a JPEG (Joint Photographic Experts Group) picture processing method, comprising the steps of S100, obtaining a JPEG picture; S200, obtaining each row of packed data of the picture; S300, decoding the packed data of the picture row by row; S400, transforming the decoded data into a 16-bit picture by an error diffusion method row by row; S500, judging if the picture is transformed into the 16-bit picture fully, if so, performing the step S500, otherwise, performing the step S200; and S600, storing the 16-bit color depth picture. By adoption of the technical scheme of the invention, the internal memory occupation is reduced, meanwhile, and the visual quality of the displayed picture is ensured by the error diffusion method.

Description

technical field [0001] The invention relates to the field of image processing, in particular to a JPEG image processing method and system for decoding and outputting a JPEG image in a 16-bit display mode. Background technique [0002] Generally, an image processing apparatus compresses image data corresponding to input from an external device in JPEG format. The image processing apparatus stores compressed image data into a memory by performing a direct memory access operation. In addition, the image processing apparatus rereads image data from the memory by performing a DMA operation upon request from an external device. There is a DMA processor instead of the central processing unit CPU that controls DMA operations and directly transfers data from memory connected to a bus that connects to a channel and vice versa. [0003] In "Apparatus and method for processing data using error diffusion" with application number "200610135948.3", JPEG image data is converted into color...

AI Technical Summary

Problems solved by technology

[0005] In the existing decoding method, after JPEG is decoded normally, the 32-bit color or 24-bit color bitmap is converted into a 16-bit color bitmap, and finally the output is displayed. This method takes up the least memory, but the visual quality is very poor

[0006] Using the above technical solution, if the visual quality is not considered, the decoded picture will have a bad effect in 16-bit display mode, especially for pictures with a large number of gradient colors; if the visual quality is considered, but progressive decoding is not used, although The display effect is good, but the memory usage is large. For some embedded products, memory resources are also very precious.

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