CODEWITHSUNDEEP
phpimageresizesize
Ormoz
Ormoz

Reputation: 3013

Best output when resizing images in PHP

I want to make a thumbnail(64X64) of images uploaded by user to reduce the overall page size. I did it using the following PHP code, But the result is really disappointing! in one instance the original file size was 554 byte (70X70). by converting it to a 64X64 image, the file size has increase to 1.43 KB! while the quality of the image is terribly degraded.

What is wrong here? Isn't it any other way to resize the images by PHP and have a better output?

Thank you very much

function image_resize($src, $dst, $width, $height, $crop=0){

  if(!list($w, $h) = getimagesize($src)) return "Unsupported picture type!";

  $type = strtolower(substr(strrchr($src,"."),1));
  if($type == 'jpeg') $type = 'jpg';

  switch($type){
    case 'bmp': $img = imagecreatefromwbmp($src); break;
    case 'gif': $img = imagecreatefromgif($src); break;
    case 'jpg': $img = imagecreatefromjpeg($src); break;
    case 'png': $img = imagecreatefrompng($src); break;
    default : return "Unsupported picture type!";
  }

  // resize
  if($crop){
    if($w < $width or $h < $height) return "Picture is too small!";
    $ratio = max($width/$w, $height/$h);
    $h = $height / $ratio;
    $x = ($w - $width / $ratio) / 2;
    $w = $width / $ratio;
  }
  else{
    if($w < $width and $h < $height) return "Picture is too small!";
    $ratio = min($width/$w, $height/$h);
    $width = $w * $ratio;
    $height = $h * $ratio;
    $x = 0;
  }

  $new = imagecreatetruecolor($width, $height);

  // preserve transparency
  if($type == "gif" or $type == "png"){
    imagecolortransparent($new, imagecolorallocatealpha($new, 0, 0, 0, 127));
    imagealphablending($new, false);
    imagesavealpha($new, true);
  }

  imagecopyresampled($new, $img, 0, 0, $x, 0, $width, $height, $w, $h);

  switch($type){
    case 'bmp': imagewbmp($new, $dst); break;
    case 'gif': imagegif($new, $dst); break;
    case 'jpg': imagejpeg($new, $dst); break;
    case 'png': imagepng($new, $dst); break;
  }
  return true;
}

Upvotes: 0

Views: 120

Answers (1)

gandaliter
gandaliter

Reputation: 10101

I think that probably nothing is wrong here. 1.43KB is not very much, so it's not clear that the image produced is inefficiently stored. As for image quality, we're talking about a very small image; resizing from 70x70 to 64x64 is very likely to produce an odd-looking result. If you have a larger image to start with then it will probably work better.

There are other PHP image libraries (e.g. WideImage), but I'd be surprised if using them would make a great deal of difference here. In fact they probably use GD internally anyway.

Upvotes: 1

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