Subband coding of images using trellis coded quantization

An image coding scheme combining subband coding and the established energy compaction technique of the discrete cosine transform (DCT) with trellis coded quantization (TCQ) is introduced. Image spectrums are split into 16 subband images using a quadrature mirror filter bank, and the DCT is performed on the lowest subband. The data is quantized using TCQ, transmitted and recombined at the receiver. It is shown that quantizing the subband data with TCQ decreases the mean-squared error (MSE) incurred in the quantization step, versus that of a Lloyd-Max scalar quantizer