I'm using a gray scale camera nd I am running threshold to remove some noise and this works well. When I want to look directly at a pixel location that is supposed to be a bright spot on the image, I get a very low reading. It's like my method to retrieve the data is improper. I'm using something like this (uchar = frame.at<uchar>(C,R). This should work and it runs, but the results cant be correct. I have used threshold like this threshold(frame, myframe,150,255,THRESH_TOZERO); To eliminate the noise, which leaves a bright line of light (LED). So the Threshold seems to do as advertised. but when I try to read at a known hot spot, i don't see the values representative. What could be incorrect with my method? Thank You