Grayscale Image Contrast Enhancement

Dear all, I have a bunch of grayscale images of cross sectional views of an artery. The contrast of images is variable (Image A and B). I am trying to detect the vessel borders as shown in attached image (Image C and D) using "Edge" command in Matlab; however, because my images have variable contrasts, I need to use a different threshold for each image to detect the borders.

I wonder if there is a command in Matlab which brings all images to a similar contrast level, especially on the borders, so that I can use a unique threshold for all images. Thanks

Answer 1

[Image Analyst]

There is an imhistmatch() function to match the histograms of two images. Give that a try.