how to subtract mask from an image and add the pixels value

please help me to code for it. I did this code but not working properly.

clear all 
close all 
f = [12 30 120 220 120 130 140 150 120 220 120 120 90 80 70 80] 
% f=imread('abc.jpg'); 
% f = rgb2gray(f); 
m = f(2:3) 
% m = imread('abc1.jpg'); 
% m = rgb2gray(m); 
[R,C] = size(f); 
for X = 1:R-(size(m,1))+1 
    for Y = 1:C-(size(m,2))+1 
        f1(X:X+size(m,1)-1,Y:Y+size(m,2)-1) = abs(f(X:X+size(m,1)-1,Y:Y+size(m,2)-1)-m);
    end 
end 
subplot(1,3,1); 
imshow(uint8(f)); 
subplot(1,3,2); 
imshow(uint8(m)); 
subplot(1,3,3); 
imshow(uint8(f1))

[Guillaume]

Please use the toolbar buttons to format your post properly. I've done it this time but since the code was written on just one line, I had to take a guess at where the comments ended. I may have got it wrong.

Your explanation is really not clear. How is the mask calculated? What does subtracting the mask (a 1x2 vector) from a 1x8 image (a 1x8 vector) mean, bearing in mind that subtraction between two non-scalar vectors of different length is not defined? What does placing a result on mean? Do you mean assign to?

[Image Analyst]

I agree with Guillaume. Your description is not clear and ambiguous - it could be interpreted several ways and your diagram is not helpful in explaining what values are in the mask, what is being subtracted, and what happens if parts of the mask are off the edge of the image. And if it's a 1x2 mask instead of a odd length like is usually used, where the output pixel gets assigned to.

Answer 1

[KALYAN ACHARJYA]

f=[12 30 120 220 120 130 140 150 120 220 120 120 90 80 70 80] 
[r c]=size(f);
m=f(2:3)
f1=[];
for i=1:r
    for j=1:c
    sub_result=f(i,j)-m
    f1(i,j)=sum(sub_result(:))
    end 
end
subplot(1,3,1);imshow(uint8(f));subplot(1,3,2);imshow(uint8(m));
subplot(1,3,3);imshow(uint8(f1));

Recomended: You can look for Block processing to avoid loops

[Hanif Ullah]

Sir it only subtract the first pixel of mask from original image. I want that it subtract the parallel vale of image like in this image

[KALYAN ACHARJYA]

See its doing, see in imshow, the f image and f1 is different

>> f

f =

    12    30   120   220   120   130   140   150   120   220   120   120    90    80    70    80

>> f1

f1 =

  -126   -90    90   290    90   110   130   150    90   290    90    90    30    10   -10    10

[Hanif Ullah]