how to remove the noise applied to particular part of color image

i have read an image into some variable for ex; 'r' ,next applied the noise to r(i,j) where i and j is the position of the noise applied.now i want to remove the noise but applying the denoising method only at the region.how to do it explain it with an example.

Answer 1

[Image Analyst]

First bet a binary image that says where the noise is, for example by just specifying the rows and columns, or using imfreehand() and poly2mask(), or stdfilt() and thresholding, or whatever gives you the noise pixels. Then just do:

% Set back to original noise-free values.
noisyImage(binaryImage) = originalImage(binaryImage);

Repeat for each color channel.

[ARUN SAI]

explain with example