[Image processing] normalization and subtracting background noise

Hi!

I am trying to normalize two images. Image A is less brighter than Image B.(A:B=0.9:1).

I'd like to correct the intensities of two to be the same,

and then i'd like to control the max and min value of the intensity to subtract the background noise.

So far, I have written the script as below, and I'm having some troubles to do so.

I appreciate your help!

----------------------------------------------------

highthreshold=;

lowthreshold=;

ma1=max(max(imageA));

ma2=max(max(imageB));

me1=median(median(imageA));

me2=median(median(imageB));

ca1=(imageA>me1*lowthreshold).*(imageA<ma1*highthreshold);

ca2=(imageB>me2*lowthreshold).*(imageB<ma2*highthreshold);

Correct=mean(mean(imageA(ca1.*ca2==1)))/mean(mean(imageB(ca1.*ca2==1)));

image_Corr=imageB*Correct;

-------------------------------------

Thanks.

Answer 1

[Changoleon]

Hi. I assume you're images are grayscale. How about you try this:

upperlim = 200; % define the maximum intensity

lowerlim = 100; % define the minimum intensity

A1 = double(imread('')); %read first image

B2 = double(imread('')); %read second image

m = (255-0)/(upperlim-lowerlim); % define the slope of the transfer function

b = 0 - (m*lowerlim); % define the y-intercept of transfer function

B1 = (m*A1)+b; % new image B2 = (m*A2)+b; % new image

You can play with upper and lower limits to find the ideal version of your images.

Sina

Answer 2

[Image Analyst]

Try imhistmatch() or mat2gray().