A novel image coding technique for noisy communications

A novel technique based on transform coding is proposed for image coding in the presence of noise. In this technique the signal is pre-filtered before the transform coding. It is shown that the prefiltered signal is unrecognized, and thus signal encryption is achieved. Therefore, this technique is called transform encryption coding. Owing to the requisite postfiltering process, channel and quantization noise spread all over the reconstructed signal from the transform encryption coding, and become less visible. In addition, the transform encryption coding not only increases the compression ratio, quality, noise insensitivity, and security level of the coded signal but also removes the blocking effect. Therefore, it can be considered as a combined source-channel coding scheme, and is suitable for applications related to noisy channel communications