title: Imagemagick issue: convert multi images to a pdf
body: <p>I converted success multi images (1 img, 2 imgs,..., 17 imgs) to a pdf, but now I have a problem when convert 26 images (200 dpi) to a pdf.</p>
  
  <p>I have 2 sites:</p>
  
  <p>site 1: I converted successfully.</p>
  
  <p>site 2: I failed, but when I change 26 images to 100 dpi, I converted success.</p>
  
  <p>I checked php.ini on 2 site: memory_limit is 256M, max_execution_time = 60</p>
  
  <p>I think problem is php.ini of site 2, but I can't find wrong setting which make convert fail. Please help me.</p>