title: Cropping images with ImageMagic produces wrong size images - why?
body: <p>There is a bunch of images that represent the pages, scanned from a book and already cropped with ImageMagic. They are all uniform, 629x625 pixels. I need to process them further to prepare for creation of a PDF: split them into odd and even pages. They are named <code>canvas-00.png</code> through <code>canvas-53.png</code></p>
  
  <p>When I use the following command to get the odd pages first, I get completely butchered images 275x563 pixels extracted from a wrong horizontal offset:</p>
  
  <pre><code>convert canvas-??.png -crop 314x625+0+0 ~/Pictures/odd/canvas.png
  </code></pre>
  
  <p>What am I doing wrong?</p>
  
  <p>PS: Originally the images were larger, contained extra margins with scanner's lid visible, and I successfully cropped them to 629x625 using a very similar command, but of course with non-zero offset of <code>+140+71</code>. So it baffles me that a visibly more trivial command with zero offset does not work at all.</p>