Analog and leaky predictive transform image coding
Erlan H. Feria · 2002
The design equations of minimum mean square error (MSE) predictive transform (PT) coding are augmented with a scalar leak factor to yield PT decoders that more rapidly attenuate the errors introduced by a noisy channel. In addition, the author investigates the analog compression of 3.6-MHz NTSC monochrome images in an additive and zero mean white noise channel environment. Analog compression means that only a fixed number of the most energetic elements of the unquantized coefficient error vector produced by the PT coder are transmitted. For the case of no channel noise, and transmission bandwidths of 3.6, 2.7, 1.8, and 0.9 MHz, a leaky 4*6 PT coder is found to yield an image quality and SNR (signal-to-noise ratio) close to that of an 8*8 KLT coder. For a noisy channel with an SNR of 11.64 dB and similar transmission bandwidths, it is shown that the PT coder significantly outperforms the KLT coder in both image quality and SNR.>