AIC - Future Work
The Advanced Image Coding codec is still experimental and in no way a finished product. My initial goal was not to make the codec too complex. The following improvements could make the AIC codec perform even better, at the cost of making it more complex:
- The H.264 standards includes a built-in deblocking filter to smooth the edges of the 4x4 image blocks. Incorporating this filter (or a modified version) into AIC may improve the visual quality of the image, especially at lower bit rates (although it might lower the objective image quality).
- The AIC codec can currently not be used for lossless image coding because of the rounding errors in the color conversion and Discrete Cosine Transform algorithms. To make AIC suitable for lossless coding, reversible color conversion and transformation algorithms must be incorporated. The JPEG-2000 standard includes a reversible color transform that might be suitable for AIC. There are also some reversible DCT transformations around (for example the BinDCT algorithm) that can be used for lossless image coding. Or maybe an integer wavelet transform is more appropriate.
- The H.264 standard defines 9 prediction modes that are reasonably fast to compute. When encoding speed is not a top priority, maybe some other prediction modes that interpolate between the left and top edge can be used. These are more computationally intensive, but may produce better results. On the other hand, increasing the number of prediction modes also increases the number of bits needed to encode the prediction mode.
These improvements are under current investigation. You are invited to make your own improvements by downloading the source code. Just let me known about your findings.