Snippets - Resize and crop

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NOTE: Most of the IM snippets have been tested on IM version 6.3.5 There may be some differences if you are using the code on other versions.

Dividing an image - Anthony 17/6/2008

Make an image look as though it is made up from individual poleroid photos. The image rotations and spacings are random with certain limits so the final image will be slightly different everytime. I have modified the code slightly to use image formats that would not normaly be in the folder miff and bmp. If you have any bmp files in the same folder as this code they will be deleted. This will also improve the quality slightly as I was using jpg format for one set of tempory images before.

  1. <?php
  2. // Original image
  3. $image = '../original_images/sunflower.jpg';
  5. // Amount of images in x
  6. $qty_x = '4';
  8. // Amount of images in y
  9. $qty_y = '3';
  11. // Get the size of the original image
  12. $size = getimagesize($image);
  14. // Size to crop the images to 
  15. //  Code modified as per sugestion of Dave to prevent problems with left over parts of the divided image).
  16. $crop_x = round( $size[0]/$qty_x + 0.5);
  17. $crop_y = round( $size[1]/$qty_y + 0.5 );
  19. // Canvas for combined images - it will be trimmed to the finished image size in the code
  20. $width = ( $size[0] * 1.5 );
  21. $height = ( $size[1] *1.5 );
  23. // Crop the image - saving as a miff format
  24. exec("convert $image -crop {$crop_x}x{$crop_y} image-%d.miff"); 
  26. // Remove the .miff from the filenames and replacing it with a bmp to save overwriting the original
  27. foreach (glob("*.miff") as $filename) {
  28. $file = str_replace('.miff', '', $filename );
  29.     exec("convert $filename -background black +polaroid $file.bmp"); 
  30. }
  32. // Delete tempory images
  33. foreach (glob("*.miff") as $filename) {
  34. unlink($filename); 
  35. }
  37. // Set $command variable
  38. $command = "";
  40. // Loop through generating the image layout
  41. for ($j = 0; $j < $qty_y; $j++) { 
  43.   for ($i = 0; $i < $qty_x; $i++) {    $n = $j>0 ? $qty_x*($j)+$i : $i; 
  44.   $offset_x= ( ($crop_x * $i ) + rand(2, 25));
  45.   $offset_y=( ($crop_y * $j ) + rand(2, 25));
  46.   $command .= " image-$n.bmp -geometry +$offset_x+$offset_y -composite" ;  } 
  47.   }
  49. // Produce the combined image - if saving as a png you could use xc:none for a transparent background
  50. exec( "convert -size {$width}x{$height} xc:#262b38 $command -trim combined.jpg"); 
  52. // Delete tempory images
  53. foreach (glob("*.bmp") as $filename) {
  54. unlink($filename); 
  55. }
  56. ?>
  58. <img src="combined.jpg"> 

For more examples and information check out the main Imagemagick section.

Clone View

Crop an image View

Crop an image into pieces View

Dividing an image View

Keep minimum image size View

New image size in variable View

Resize if over certain size View

Resize keep aspect ratio. View

Resize no aspect ratio. View

Speed up jpg resize View