An image transmission method and system

Abstract

The invention provides an image transmission method and an image transmission system, a link rate assessed value acquired by a link rate assessment method of the image transmission method is close toan actual rate of an application layer, the link rate change trend can be reflected more quickly and accurately, and thus a hardware encoder can quickly and accurately adjust a code rate, and performcorresponding image transmission. According to the image transmission method provided by the invention, the video code rate can be dynamically adjusted in the noisy environment or long-distance transmission application, the mosaic phenomenon can be effectively avoided, the wireless image transmission quality can be improved, and the image can be returned to the user as smoothly as possible.

Description

technical field [0001] The present invention relates to an image transmission method and system, in particular to an image transmission method and system for dynamically adjusting code rates based on real-time link transmission quality. Background technique [0002] With the development of wireless communication technology, in terms of video transmission, the image transmission system gradually adopts wireless transmission to replace the original wired transmission mode. At present, most common wireless image transmission systems use WIFI to transmit H.264 compressed video. Generally, the peak rate of 6Mbps to 15Mbps can meet the requirements of high-quality image transmission. Since the IEEE802.11 protocol uses CSMA / CA to avoid link collisions, the WIFI transmission rate will fluctuate greatly in multi-user noisy environments or long-distance applications. Transmission with a fixed bit rate will cause delay and mosaic. If the code rate transmission can be dynamically adj...

AI Technical Summary

Problems solved by technology

However, due to the early birth of the WIFI protocol, its link adaptive algorithm generally cannot meet the requirements of the image transmission system. The reasons are as follows: WIFI link adaptive algorithm or rate control is generally based on the packet error rate Error Ratio), a message generally undergoes several retransmissions when it is transmitted in a noisy environment, and it is determined whether to reduce the rate according to the result of the retransmission

When the user layer acquires the new physical layer transmission rate, the upper layer image transmission quality has deteriorated

Therefore, the link adaptation algorithm in the prior art cannot obtain a good image transmission effect

[0004] Especially for long-distance transmission applications, for long-distance image transmission, the effective rate of the application layer will be greatly reduced. If the bit rate adopted is not suitable, the quality of image transmission will be significantly deteriorated, and it cannot be smoothly transmitted to users

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