Plot image in 2d plain and apply operations like translation/rotation and reflection

I want to read an image on matlab and on 2d plain perform changes of its coordinates as I would have done on a graph

img = imread('img.png');
sz = size(img);
imshow(img);

I am very new to matlab and do not understand much too. I know that imread will get 3d matrix. First 2 with original values

and the last for RGB.

Those are color values and I do not thin that can be used to apply rotation or translation

Below is the example oof what I actually want to do.

Answer 1

[Matt J]

Use imrotate, imtranslate, and flip.

[Farhan]

i have to do it manually as I will be given matrix not the operation

[Matt J]

You could decompose the matrix into rotations, and flips to see what the sequence of operations should be. Alternatively, you could use imwarp, together with simtform2d, which will let you specify the transformation with a matrix.

[Farhan]

can you provide an example, as I am new to matlab

[Matt J]

rgbImage = imread('peppers.png');

T = [0.6428   -0.7660         0        
     0.7660    0.6428         0         
          0         0    1.0000 ];  %transformation matrix


tform=simtform2d(T);

imshow(imwarp(rgbImage,tform))

Answer 2

[Image Analyst]

rgbImage = imread('peppers.png');
title('Original')
nexttile
imshow(rgbImage);
img2 = imrotate(rgbImage, 90);
title('Rotated')
nexttile
imshow(img2);
img3 = flipud(rgbImage);
nexttile
imshow(img3);
title('Flipped top-to-bottom about horizontal axis')

For more sophisticated transforms, see Steve's blog:

Spatial transformations Defining and applying custom transforms Steve on Image Processing