Image objects characteristics, area and shape

Hi, I am working on images with crowded objects with various circularity and sizes. Is there any way to detect and list all their shapes and sizes (grouping ones with the same area, and grouping ones with the same shape after)? Any answer is appreciated.

Answer 1

[Image Analyst]

Sure. I do that in my Image Segmentation Tutorial http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862&sort=downloads_desc

For example:

props = regionprops(labeledImage, 'Area');
allAreas = [props.Area];
bigAreaIndexes = find(allAreas > 10000); % Blobs with an area > 10000 pixels.
% Extract only the big area blobs:
bigBlobs = ismember(labeledImage, bigAreaIndexes);

Similar for circularity or any other measurement.

[Tian Tian]

Hi, thank you for your help. When I use the regionprops to extract object information, it only gave me three area values (i used multithreholding, so my image is like black gray & white). I wonder whether the threholded image is regarded as three objects only (even there are some little grains)? Thank you.

[Tian Tian]

Because when a table is used to list all of them, it listed all pixels (which is the image size). The code I used for threholding is: I0 = imread('A1-1a-mulsoil_0703.tif'); imshow(I0) I = imgaussfilt(I0,2); thresh = multithresh(I,2); seg_I = imquantize(I,thresh); figure imshow(seg_I,[]) title ('threholded')

Could you please have a look? Many thanks.

[Image Analyst]

A look at what? You forgot to post your image.

In the meantime, take a look at this: http://www.mathworks.com/matlabcentral/answers/13205#answer_18099