From: Roshan Rajaratnam on
Hey guys can someone gimme a clue to how to extract the edge points of a signature plz?
From: ImageAnalyst on
Threshold and then call bwboundaries().
From: Roshan Rajaratnam on
ImageAnalyst <imageanalyst(a)mailinator.com> wrote in message <7693ea0f-48d5-4be2-b274-04dd67128100(a)p2g2000yqh.googlegroups.com>...
> Threshold and then call bwboundaries().


thresholding as in before the rgb to binary conversion?
From: ImageAnalyst on
Huh? No. How are you going to threshold an RGB image? You could do
"color classification" by thresholding each of the monochrome RGB
planes individually, like I do in this demo:
http://www.mathworks.com/matlabcentral/fileexchange/26420-simplecolordetection

but I was thinking that you're starting with a monochrome image and
then threshold it like this
binaryImage = grayImage < thresholdValue;

If you don't have a gray scale image to start with, then convert your
rgb image into gray scale either with
grayImage = rgb2gray(rgbImage);
or
redPlane = rgbImage(:, :, 1);
greenPlane = rgbImage(:, :, 2);
bluePlane = rgbImage(:, :, 3);

binaryImage = redPlane < thresholdValue;
or using whatever color plane or combination of them gives you the
best contrast.