how can i calculate a variance of each BLOB in image

hello every one; i need to know how to calculate a variance of each blob contains in one image, thank you in advance

Answer 1

[Image Analyst]

Ask regionprops to return PixelValues for the blobs.

measurements = regionprops(labeledImage, 'PixelValues');

Then for the kth blob:

blobVariance(k) = var(measurements(k).PixelValues);