let say your image is I, and if you know your know the areas for your image to crop and those remain for all images then following command should work.
Top = 30;% pixel
bottom =10;%pixels from bottom
margin_left = 30;%pixel from left to right
margin_right = 10;%pixel from right to left
I = rand(729,1024); % random matrix with same dimensions as your image;
J = I(top:size(I,1) - bottom , margin_left:size(I,2) - margin_right);
This should work, you can set the four parameter given above based on your image analysis.
