MATLAB: How to count 3 group red pixel of original image

Question

How can I count red pixel (3 groups) of original image Like this output?

Thank you.

Answer 1

See https://www.mathworks.com/help/images/examples/color-based-segmentation-using-k-means-clustering.html?searchHighlight=color%20segmentation&s_tid=doc_srchtitle

Or see my File Exchange for Color Segmentation algorithms http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862&sort=downloads_desc

Or see my attached demo.