% BALANCE

% balance an image

% must have run getbalance first

newImage = test_image;

lighting = 3;

method = 2;

filePath = 'C:\Documents and Settings\Kim Shultz\My Documents\ee362\balanced pictures\';

fileName = cat(2,filePath,test_image.jpg');

% lighting number as follows:

% 1 = sun

% 2 = shadow

% 3 = flourescent

% 4 = incandescent

% 5 = flash

%method for balancing as follows:

% 1 = linear subtract: subtract illuminant bias

%add/subtract to R, G and B to match mean value

% 2 = linear scale: scale R, G and B to match mean value by multiplying by

% ratio

% 4 = grey world multiplicative - scale image's G and B means (by addition)

% to match mean value

if method == 1

Rav = mean(newImage(:,:,1));

Rav = mean(Rav);

Gav = mean(newImage(:,:,2));

Gav = mean(Gav);

Bav = mean(newImage(:,:,3));

Bav = mean(Bav);

targetav = mean([Rav Gav Bav]);

scale = (1-balanceValues(:,lighting))*targetav;

newImage(:,:,1) = newImage(:,:,1) + scale(1);

newImage(:,:,2) = newImage(:,:,2) + scale(2);

newImage(:,:,3) = newImage(:,:,3) + scale(3);

newImage(:,:,3) = newImage(:,:,3)+Bscale;

%if any values are over 1, cutoff at 1

newImage = min(newImage,1);

%if any values are under 0, cutoff at 0

newImage = max(newImage,0);

end

if method == 2

newImage(:,:,1) = newImage(:,:,1)/balanceValues(1,lighting);

newImage(:,:,2) = newImage(:,:,2)/balanceValues(2,lighting);

newImage(:,:,3) = newImage(:,:,3)/balanceValues(3,lighting);

%if any values are over 1, cutoff at 1

newImage = min(newImage,1);

end

if method == 3

Rav = mean(newImage(:,:,1));

Rav = mean(Rav);

Gav = mean(newImage(:,:,2));

Gav = mean(Gav);

Bav = mean(newImage(:,:,3));

Bav = mean(Bav);

targetav = mean([Rav Gav Bav]);

newImage(:,:,1) = newImage(:,:,1)+(targetav-Rav);

newImage(:,:,2) = newImage(:,:,2)+(targetav-Gav);

newImage(:,:,3) = newImage(:,:,3)+(targetav-Bav);

%if any values are over 1, cutoff at 1

newImage = min(newImage,1);

%if any values are under 0, cutoff at 0

newImage = max(newImage,0);

end

if method == 4

Rav = mean(newImage(:,:,1));

Rav = mean(Rav);

Gav = mean(newImage(:,:,2));

Gav = mean(Gav);

Bav = mean(newImage(:,:,3));

Bav = mean(Bav);

targetav = mean([Rav Gav Bav]);

newImage(:,:,1) = newImage(:,:,1)*(targetav/Rav);

newImage(:,:,2) = newImage(:,:,2)*(targetav/Gav);

newImage(:,:,3) = newImage(:,:,3)*(targetav/Bav);

%if any values are over 1, cutoff at 1

newImage = min(newImage,1);

%if any values are under 0, cutoff at 0

newImage = max(newImage,0);

end

imwrite(newImage,fileName,'jpeg');