MATLAB: Implement attacks on image

imageimage attacksImage Processing Toolbox

Hi everybody, I want to implement the following attacks on gray scale image; Scaling (0.5, 2), Translation (10, 10) and Shearing (0.2, 0.2), any one have any idea about how do that in matlab. thank u in advance

Best Answer

imresize(), circshift(), and imwarp().

Related Solutions

MATLAB: Fractional fourier transform

Use fft2 on each of the colour planes in turn, for example

Ft_image(:,:,1) = fft2(Image(:,:,1));
Ft_image(:,:,2) = fft2(Image(:,:,2));
Ft_image(:,:,3) = fft2(Image(:,:,3));

(assuming that you don't want the Fourier transform in colour space - I don't think that would make sense).

I don't know about the fractional Fourier transform.

MATLAB: Inverse of a projective transformation doesn’t work with imwarp

Try this:

I = imread('cameraman.tif');
imshow(I)
tform = projective2d([0.96119642,-0.44830978,-0.00025835048;
                      0.14598410,1.6215615,6.6809996e-05;
                     1496.0447,1046.4227,1]);
[J, Jref] = imwarp(I, imref2d(size(I)),tform);
disp(Jref)
figure
imshow(J)
tInv = invert(tform);
K = imwarp (J,Jref, tInv);
imshow(K);

imref2d helps capture the full spatial location of the output image. Notice how the X/YWorldLimits are large numbers? This gets lost when you dont use spatial referencing - hence, in your post, the input you are giving the second imwarp is not strictly the mathematical output of the first imwarp call.

Best Answer

Related Solutions

MATLAB: Fractional fourier transform

MATLAB: Inverse of a projective transformation doesn’t work with imwarp

Related Question