Recognizing shapes in (binary) matrix

Hey all,

I'm trying to find a shape in a binary image.

In order to do that i am using bwboundaries() function to identify all the shapes in the image. I get a cell with matrices (the size of X by 2), of all the objects. Each matrix represent the number of pixels in the object.

For example, lets say there are two matrices, almost the same size. One representing the shape of a line, the other the shape of a circle (not exactly a line or a circle).

My question is - can i differ the line from the circle ?

Any help appreciated.

Yair

Answer 1

[Doug Hull]

If you KNOW that you are either dealing with a line or a circle, then could you look at the MajorAxisLength and MinorAxisLength from RegionProps. Their ratios should be wildly different, yes?

Doug

[Sean de Wolski]

Also: EquivalentDiameter v. MajorAxisLength

[Yair]

Thank you both.

Gonna try this now and let you know.

[Yair]

Worked like a charm!

If anyone stumbles across this, you could do:

STATS1(1).MajorAxisLength / STATS2(1).MinorAxisLength;

to get the ratio of the two axis (where STATS1=regionprops(h, 'MajorAxisLength'), and STATS2 is the minor axis).