How get corner of triangle?

May i get the corner of triangle if i use regionprops functions? and if it possible, which property from regionprops that i can use? is that any sample code?

i wanna learn more..

Thanks..

Answer 1

[Image Analyst]

I don't think regionprops would help. regionprops() measures regions. It might be able to find triangle-shaped regions for you, but as far as taking a single triangle and finding which pixels are at the corner, it can't do that. What about using the corner() function? Have you tried that? Or look at bwboundaries() and try to identify sharp turns.

And, of course, posting an image never hurts. In fact, it's usually mandatory.

[Ryan]

To build on IA's answer, if you use bwboundaries to find the perimeter pixel locations, you can take a simple difference for the (x,y) vectors and then find peaks in the tangents to locate the corners of the triangle. You'll have to handle the special case where the bwboundaries starts indexing at a corner if you use that method.

[Cahaya]

to IA's : i've tried corner function. in http://www.csse.uwa.edu.au/~pk/research/matlabfns/ under subtittle spatial feature detection, there a harris.m ( http://www.csse.uwa.edu.au/~pk/research/matlabfns/Spatial/harris.m ) using derivative5.m and gaussfilt.m. Can u help me, in file harris.m i want to plot a corner point to the image. what i must added in code?