I am trying to use edge detection in my applicaton.
case1)
I load the image(8 bit) and apply Edge detection using Simple edge with level type:Absolute and I specify the threshold level. Now depending on the threshold level, the positions of the edges detected varies.That is perfectly fine.
case2)Before using the edge detector, I use manual threshold with threshold levels Min=128 and Max=255. After applying, the image is converted into a binary image. Now if I go ahead and apply the edge detection tool,It picks the edge at the point where the background(black) changes to white( binary value 1).
Now if in edge detection tool I try to specify t
he threshold level again, say 230 how is the edge located. As far as my understanding goes, since the pic we are looking at is a binary one the threshold level shouldn't matter now. It would pick the edge depending on whether the pixel value is 0 or 1.
I have personally observed that when I change the threshold level in the edge detection , the position of the edge seems to shift slightly even though the image is a binary one.
