How to find area of specific region in binary image ?
10 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
For example, I have image with
- region1 white,
- region2 black,
- region3 white,
- region4 black and
- region5 white.
How can I know pixel density in region4 and how to convert that specific area mm2/cm2 ?
2 commentaires
Image Analyst
le 29 Nov 2020
What do you mean by pixel density? All regions of the image have the same density (pixels per unit area). Or do you mean "optical density", in other words, intensity of a gray scale image in region 4?
Réponses (1)
Image Analyst
le 30 Nov 2020
Modifié(e) : Image Analyst
le 30 Nov 2020
See my Image Segmentation Tutorial in my File Exchange:
In short, segment your image by thresholding or whatever to get a mask, then do
props = regionprops(mask, grayImage, 'Area', 'MeanIntensity');
for k = 1 : numel(props)
fprintf('Blob #%d has an area of %d pixels (%.2f sq. cm), and mean intensity of %.2f\n', ...
k, props(k).Area, props(k).Area * cmPerPixel^2, props(k).MeanIntensity);
end
To see how to determine the number of pixels per cm, see my attached spatial calibration demo.
6 commentaires
Image Analyst
le 1 Déc 2020
areaOfBlob3 = allAreas(3);
I think that's SO obvious that I'm not sure it's what you mean, so try to explain better.
Voir également
Catégories
En savoir plus sur Image Processing Toolbox dans Help Center et File Exchange
Produits
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!