Returning specific regions

Question

Say that I have a labeled image, where I have calculated the area of each region. How can I return specific regions? That is, say I want to return the regions that have >=300 and <500?

Thanks.

Answer 1

You can group the results of regionprops into a vector and use it for indexing:

rg = regionprops( L, 'Area' );
allArea = [rg(:).Area]; % grouping all area values into a single vecotr
labels = find( allArea >= 300 & allArea < 500); % select relevant regions