sum of absolute differences

Good evening everyone,

I have two images which I seek correspondence by correlation using the sum of absolute differences (SAD) to find the disparity map.

I do not know how to apply the formula of SAD.

thank you

[vimal]

You can directly use correlation method..

corr2(im1,im2) is the code for calculating the correlation between two images.

for more details type

doc corr2

in command window..

Answer 1

[Jan]

While imabsdiff is implemented as efficient MEX (no temporary array created), you can calculate the "sum of absolute differences" easily by hand also:

img1 = rand(640, 480, 3);
img2 = rand(640, 480, 3);
difference = img1 - img2;
absolute = abs(difference);
result = sum(absolute(:));

It is less obvious for UINT8 images, because abs(uint8(10) - uint8(20)) is not uint8(10), uint8(0) due to the saturation effects. If this is not wanted, convert the UINT8 image to double at first.

Answer 2

[Alex Taylor]

If you have the Image Processing Toolbox, consider looking at the function imabsdiff as a starting point for computing the absolute difference between two images.

help imabsdiff

Answer 3

[indhumathi gunasekar]

i have two 16*16 matrix,i need to find SAD between this. can anyone help me out?