// Original image
$image = $input14;

// Amount of images in x
$qty_x = '4';

// Amount of images in y
$qty_y = '3';

// Get the size of the original image
$size = getimagesize($image);

// Size to crop the images to 
// code modified as per sugestion of Dave to prevent problems with left over parts of the divided image.
$crop_x = round( $size[0]/$qty_x + 0.5);
$crop_y = round( $size[1]/$qty_y + 0.5 );

// Canvas for combined images - it will be trimmed to the finished image size in the code
$width = ( $size[0] * 1.5 );
$height = ( $size[1] *1.5 );

// Crop the image
exec("convert $image -crop {$crop_x}x{$crop_y} image-%d.miff"); 

// Remove the .miff from the filenames
foreach (glob("*.miff") as $filename) {
$file = str_replace('.miff', '', $filename );
    exec("convert $filename -background black +polaroid $file.png"); 
}

// Delete tempory images
foreach (glob("*.miff") as $filename) {
unlink($filename); 
}

// Set $command variable
$command = "";

// Loop through generating the image layout
for ($j = 0; $j < $qty_y; $j++) { 

  for ($i = 0; $i < $qty_x; $i++) {    $n = $j>0 ? $qty_x*($j)+$i : $i; 
  $offset_x= ( ($crop_x * $i ) + rand(2, 25));
  $offset_y=( ($crop_y * $j ) + rand(2, 25));
  $command .= " image-$n.png -geometry +$offset_x+$offset_y -composite" ;  } 
  }

// Produce the combined image
exec( "convert -size {$width}x{$height} xc:#262b38 $command -trim combined.jpg"); 

// Delete tempory images
foreach (glob("image-*.png") as $filename) {
unlink($filename); 
}