Patent ID: 8340448

Claim:
A method of operating a processing apparatus, the method comprising: for a first region of an ordered series of transform coefficients of a block of image data, the ordering from low to high spatial frequency according to a transform, the first region possibly the whole region, and for a fixed quantization method that quantizes coefficients to quantized values that have amplitudes including a most likely-to-occur amplitude, a second-most likely-to-occur amplitude and at least one other amplitude, including a third-most likely-to-occur amplitude: quantizing and encoding the first region and any other regions of the ordered series to form a coded bitstream using the processing apparatus; and outputting or storing the coded bitstream; wherein the quantizing and encoding of the first region uses one or more variable length code (VLC) mappings, and wherein the quantizing of the first region includes quantizing to have the second-most likely-to-occur amplitude at least one coefficient that would be quantized by the fixed quantization method to have the most likely-to-occur amplitude, quantizing to have the most likely-to-occur amplitude at least one coefficient that would be quantized by the fixed quantization method to have the second-most likely-to-occur amplitude, and using the fixed quantization method to quantize any coefficient that is quantized by the fixed quantization method to have other than the most likely-to-occur amplitude, other than the second-most likely-to-occur amplitude, or other than the third-most likely-to-occur amplitude.