using vision.BlobAnalysis to create BLOBs ,

for detecting motion, i used vision.BlobAnalysis to create BLOBs... and then i wanna know how to extract geometric attribute from each blob : MAJORAXIS, MINORAXIS, ORIENTATION? anyone can help me please

Answer 1

[Walter Roberson]

Use regionprops() from the Image Processing Toolbox

Answer 2

[Dima Lisin]

To do that you have to configure the vision.BlobAnalysis object to give you those outputs:

blobAnalyzer = vision.BlobAnalysis('MajorAxisLengthOutputPort', true, ...
  'MinorAxisLengthOutputPort', true, 'OrientationOutputPort', true);

Now if you call the step method you will get all those outputs:

[area, centroid, bbox, major, minor, orientation] = step(blobAnalyzer, I);

You can also turn the area, centroid, and bbox outputs off if you don't need them.

[syhem samti]

here the message error: " Error using vision.BlobAnalysis/step Too many output arguments; 6 output(s) requested but only 2 output(s) available."

[Dima Lisin]

Can you post how you create the vision.BlobAnalysis object, and how you call the step() method?