A16 – Color Image Segmentation

In image segmentation, a region of interest (ROI) is picked out from the rest of the image such that further processing can be done on it. Selection rules are based on features unique to the ROI.

normalized chromaticity coordinates
- represent color space not by the RGB but by one that can separate brightness and chromaticity (pure color) information

Per pixel, let I = R+G+B. Then the normalized chromaticity coordinates are

We note that r+g+b = 1 which implies r,g and b can only have values between 1 and 0 and b is dependent on r and g since b = 1-r-g.from R G B, the color space has been transformed to r g I where chromatic information is in r and g while brightness information is in I.
Parametric vs Non-Parametric Probability Distribution Estimation

Segmentation based on color can be performed by determining the probability that a pixel belongs to a color distribution of interest.

The probability that a pixel with chromaticity r belongs to the ROI is then
Histogram backprojection

Histogram backprojection is one such technique where based on the color histogram, a pixel location is given a value equal to its histogram value in chromaticity space.

Using the image:
cropping an the image:
Thus, we will use the yellow ball as the ROI.

We will use to techniques.
Parametric:

Non-Parametric

Acknowledgements:

Mark Leo - for the help.

Grade:
10/10
- because I think I did what is needed to do. And I think the image is well segmented.