Color and Edge Descriptors                       

• Color Features.

                                    - 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

• Edge Detection                                                                       

                              - 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.