I want find only red pixels which are greater than threshold. and set those redpixels values to 1 others to 0

I want find only red pixels which are greater than threshold. and set those redpixels values to 1 others to 0 to create a new matrix.

R>th then how to create a new matrix with 1 and 0's.I am a beginner to matlab

Answer 1

[Image Analyst]

See my full demo at http://www.mathworks.com/matlabcentral/fileexchange/26420-simplecolordetection

[Stelios Fanourakis]

Image Analyst in case you are able to see this comment. I tried your SimpleColorDetectio​n demo. I finally get the red contour of my image. But it gives the red contour into a black background. I want to plot the pixel values inside this contour area. Any idea of how to do that?

[Image Analyst]

How did you get the red line there? Did you plot it there? Or you just got this image from somewhere with the red line already in it? Please post this in a separate question (not here in senthil's question), and I'll solve it for you. What you are asking is really very easy. Just get a mask for the red line, use poly2mask(), and then plot the pixel values (whatever that means - you'll have to explain that some more).