Subband VPIC with classified joint vector quantization

摘要

Subband coding was combined with visual pattern image coding to eliminate the blockiness and reduce the jagged edge artifact. A new set of higher resolution, multi-level quantization 2 × 2 patterns was designed to code the highly compacted lowest-frequency band signals and improved the visual quality significantly. These edge patterns are also very effective classifiers for coding the remaining bands through simple classified joint vector quantization.