Color Average and Variance adjustment

Hi! I am working on a project that requires the adjustment of color average and variance of an image based on another image. This is the sample image. I want to adjust the color average and variance of the umbra region based on the values of the sunshine region.

I got the average and variance of the images using:

mean_sunshine=mean2(nonzeros(sunshine{1}))
var_sunshine=var(nonzeros(double(sunshine{1})))

mean_umbra=mean2(nonzeros(umbra{1}))
var_umbra=var(nonzeros(double(umbra{1})))

How to I perform the adjustments after computation? Thanks :)

Answer 1

[Image Analyst]

Just do something within the mask, for example

yourImage(mask) = slope * yourImage(mask) + offset;

[Maria Jeseca Baculo]

Thanks, but is there a solution similar to your answer in https://www.mathworks.com/matlabcentral/answers/31510-how-to-change-mean-and-variance-values-in-image that would be applicable in my case?