Question

How can I crop an image automatically through the upload process? Is there php function to do that?

I want my webpage to display the images with the same dimension from various dimension of the original images by cropping it.

Or any idea?

Answer 1

Say this as max_size.php

<?php header('Content-type: image/jpeg');
function resampleimage($maxsize, $sourcefile, $imgcomp=0){
$g_imgcomp=100-$imgcomp;
    if(file_exists($sourcefile)){
    $g_is=getimagesize($sourcefile);
        if($g_is[0] <= $maxsize && $g_is[1] <= $maxsize){
            $new_width=$g_is[0];
            $new_height=$g_is[1];
        } else {
            $w_adjust = ($maxsize / $g_is[0]);
            $h_adjust = ($maxsize / $g_is[1]);
      if($w_adjust <= $h_adjust){
          $new_width=($g_is[0]*$w_adjust);
          $new_height=($g_is[1]*$w_adjust);
      } else {
          $new_width=($g_is[0]*$h_adjust);
          $new_height=($g_is[1]*$h_adjust);
      }
    }
    $image_type = strtolower(strrchr($sourcefile, "."));

    switch($image_type) {
      case '.jpg':
         $img_src = imagecreatefromjpeg($sourcefile);
         break;
      case '.jpeg':
         $img_src = imagecreatefromjpeg($sourcefile);
         break;
      case '.png':
         $img_src = imagecreatefrompng($sourcefile);
         break;
      case '.gif':
         $img_src = imagecreatefromgif($sourcefile);
         break;
      default:
         echo("Error Invalid Image Type");
         die;
         break;
   }
  $img_dst=imagecreatetruecolor($new_width,$new_height);
  imagecopyresampled($img_dst, $img_src, 0, 0, 0, 0, $new_width, $new_height, $g_is[0], $g_is[1]);
  imagejpeg($img_dst);
  imagedestroy($img_dst);
  return true;
  } else {
  return false;
  }
}
resampleimage($_GET['maxsize'], $_GET['source']);
?>

In the page where you have image

<img id="img" src="max_size.php?maxsize=152&source=[some image path]" />