JPG-RESIZE.PHP

I quickly wrote this script to help out a web hosting client whose developer was insisting I install ImageMagik on our server. It allows you to put up resized versions of jpegs without going through the fuss of working on them with a graphics editor. There are three functions: image_resize allows you to specify a new width and height for an image. image_horizontal_resize and image_vertical_resize are wrappers for the first and allow you to specify only the width or the height. The last parameter in these functions is a boolean, and determines if the original image is made available for download or not.

To use the functions, save the script to a file called jpg-resize.php. If you decide to call it something else, don't forget to change the beginning of $src variable in the image_resize function. Include the script at the beginning of your php files <? include("jpg-resize.php"); ?> and call the function from wherever you want to place an image.

<?
function image_resize($image_file, $width, $height, $download)
         {
         $src = "jpg-resize.php?" .
                "image_file=" . urlencode($image_file) . "&" .
                "width=" . $width . "&" .
                "height=" . $height;

         $img = "<img " .
                "border=\"0\" " .
                "width=\"" . $width . "\" " .
                "height=\"" . $height . "\" " .
                "src=\"" . $src . "\" />";

         if($download == true)
            $img = "<a href=\"" . $image_file . "\">\n" .
                   $img . "</a>";

         echo($img);
         }

function image_horizontal_resize($image_file, $width, $download)
         {
         $original_size = getImageSize($image_file);
         $original_width = $original_size[0];
         $original_height = $original_size[1];

         $height = round($original_height * ($width / $original_width));

         image_resize($image_file, $width, $height, $download);
         }

function image_vertical_resize($image_file, $height, $download)
         {
         $original_size = getImageSize($image_file);
         $original_width = $original_size[0];
         $original_height = $original_size[1];

         $width = round($original_width * ($height / $original_height));

         image_resize($image_file, $width, $height, $download);
         }

if(isset($_GET))
  {
  header("Content-type: image/jpeg");

  $image_file = $HTTP_GET_VARS["image_file"];
  $width = $HTTP_GET_VARS["width"];
  $height = $HTTP_GET_VARS["height"];

  $original_size = getimagesize($image_file);
  $original_width = $original_size[0];
  $original_height = $original_size[1];

  $original_jpg = imageCreateFromJPEG($image_file);
  $resized_jpg = imageCreateTrueColor($width, $height);

  imageCopyResized($resized_jpg, $original_jpg, 0, 0, 0, 0,
                   $width, $height, $original_width, $original_height);

  imageJPEG($resized_jpg);
  imageDestroy($resized_jpg);
  }
?>