how to generate histograms for superpixel?

I have an RGB image converted into Lab image. Generated 44 superpixels and calculated MeanIntensities and pixellist and centroids.How to generate histograms for each superpixel?

Answer 1

[Image Analyst]

You can loop over the properties extracted by regionprops

props = regionprops(labeledImage, superPixelImage, 'PixelValues');
for k = 1 : length(props)
    % Get the pixel values of this region alone:
    thesePixelValues = props(k).PixelValues;
    % Histogram this region's gra levels.
    counts = imhist(thesePixelValues);
    % Now do something with counts....
end

[Ad]

for  i=1 : length(lprops)
thesePixelValues = lprops(i).PixelValues;
counts = imhist(thesePixelValues);
end

I got counts value as 256*1 double. Every value is zero.

Can you explain this?