The Dominant Color Descriptor (mpeg7:DominantColor)

The Dominant Color Descriptor (DCD) is one of the color descriptors of MPEG-7, which captures the salient colors of images, video frames, and regions of interest in images and frames.

<> mpeg7:DominantColor "162 43 41 0.55 1"^^mpeg7:DominantColorType .

A dominant color of the image forest.jpg is defined with the following values of the DominantColorType datatype:

  • The first three numbers (162, 43, and 41) represent the vector of the corresponding color space component values
  • The fourth value (0.55) is the ratio of the number of pixels corresponding to the color and the total number of pixels in the frame normalized to a value within the range [0, 1]
  • The last value (1) represents the spatial coherency, i.e., the overall spatial homogeneity of the dominant color in the frame calculated as the linear combination of the individual spatial coherence values weighted by the corresponding percentage non-uniformly quantized to 5 bits

The MPEG-7 standard allows a maximum of eight dominant colors for a single frame, but typically 3–4 colors provide a good characterization.