imcrop() not working for certain part of image..

I'm trying to crop certain small portion of image using the below code..

z=imread('lighthouse.png');
imc1 = imcrop( z, [630 470 7  7 ] );
disp (imc1);

But, it ended up with a empty matrix.. Even though the original matrix contains pixels in that part... (It works good for images with low dimensions... but working with high dimensional images causes some error..)

[Jan]

I'm convinced, that your assumption "the original matrix contains pixels in that part" is not correct. Check this explicitly - see KSSV's example.

Answer 1

[KSSV]

Dimensions of your image are less then (630,470) which you have specified. YOu have to resize the image to crop to the given locations.

z=imread('lighthouse.png');
[nx,ny,nz] = size(z) ;
if nx < 630 || ny < 670 
    fprintf('Check the dimensions of image\n') ;
    fprintf('Resize the image\n')
    z = imresize(z,[1000 1000])     ;

      imc1 = imcrop( z, [630 470 7  7 ] );
      disp (imc1);
  end

[Jan]

While resizing to an arbitrary size is not necessarily useful, checking the dimensions before cropping is the way to go.