Subsampling and HVQ Design
At the present our HVQ design is not good enough to map an 8x8 block
Reduce block to 4x4 before mapping
- Interpolate back before computing bitstream
Used 10-bit codes at every stage (1024 AC blocks at most)
Complexity:
- 79 adds, 17 shifts, 15 look-ups, per 8x8 block
- Regular JPEG is an order of magnitude more expensive