GOAL:create an intensity graph. locate the centroid of the an object with the highest intensity value. display coordinates. 1: I have created a graph, where there is a single spot of the highest intensity (10, 40). I am trying to locate this location, not by searching the array for the highest value (which I know is possible), but by using image analysis to find the intensity, then locating the centroid. 2: Export the graph, then threshold the image so that only the highest intensity is isolated. 3: When the centroid is located, you can see that the resulting coordinates are different. I understand that (0,0) on a graph is located at the bottom left hand corner, which is different from the (0,0) on an image which is at the upper right hand corner. I've also tried to eliminate the excess pixels that were created from the borders of the graph. Finally after subtracting the borders, my calculated coordinates were (20,106), which are obviously far different from (10,40). QUESTION: I'm not sure if the if the resolution changed when I exported the image, or whether it is something else. But I have exported the image at 24-image depth and 100% quality (jpeg). At this point I'm not able to figure this one out on my own and am seeking help and advice.

Machine Vision

Instead of exporting and importing the image, use IMAQ Array to Image instead.

Kevin C.
National Instruments
NI Vision

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