how to convert ROI into zero values.

I have colored image with a damaged region(ROI). I want to convert the pixel values of damaged area into zero values. AN example output needs to be like the attached one below What is the process should i follow ?

[Peter O]

How is your ROI defined and what is the structure of your image data? If the image is a grayscale matrix, it should be as straightforward as identifying the indices of the ROI, then

    A(idces) = 0

If your ROI is a rectangle of the form [x0 y0 w h] you could use the meshgrid command to get the coordinates and, optionally, convert them to the single-index form I used above. (You could also use A(X,Y) = 0)

Answer 1

[Image Analyst]

Use regionfill().