- Color Histogram defined in the Hue-Saturation Value color space with fixed color space quantization.
- Each 16x16 macroblock consists of 16 hue levels, each level corresponding to four saturation levels per luminance value.
- If Hhvs represents a color with quantized hue at quantized saturation and quantized value, then the colors in the reference histogram are sorted in the following order: H000 …H003 H010 …H013 H020 …H023 H030 …H033 …H133 … H1533
- Kirsch Operator is selected because supplies the most strongly pronounced gradient direction as edge strength of a pixel.
- Apply 8-kernal Krisch Operator to luminance value of each macroblock
- Generate histogram accumulation for each macroblock with 8 bins corresponding to each type of edge strength.