image_gd_resize

• Drupal 4.6
• Drupal 4.7
• Drupal 5
• Drupal 6

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Definition

image_gd_resize($source, $destination, $width, $height)
includes/image.gd.inc, line 79

Description

Scale an image to the specified size using GD.

Related topics

Name	Description
Image toolkits	Drupal's image toolkits provide an abstraction layer for common image file manipulations like scaling, cropping, and rotating. The abstraction frees module authors from the need to support multiple image libraries, and it allows site...

Code

<?php
function image_gd_resize($source, $destination, $width, $height) {
  if (!file_exists($source)) {
    return FALSE;
  }

  $info = image_get_info($source);
  if (!$info) {
    return FALSE;
  }

  $im = image_gd_open($source, $info['extension']);
  if (!$im) {
    return FALSE;
  }

  $res = imagecreatetruecolor($width, $height);
  if ($info['extension'] == 'png') {
    $transparency = imagecolorallocatealpha($res, 0, 0, 0, 127);
    imagealphablending($res, FALSE);
    imagefilledrectangle($res, 0, 0, $width, $height, $transparency);
    imagealphablending($res, TRUE);
    imagesavealpha($res, TRUE);
  }
  elseif ($info['extension'] == 'gif') {
    // If we have a specific transparent color.
    $transparency_index = imagecolortransparent($im);
    if ($transparency_index >= 0) {
      // Get the original image's transparent color's RGB values.
      $transparent_color = imagecolorsforindex($im, $transparency_index);
      // Allocate the same color in the new image resource.
      $transparency_index = imagecolorallocate($res, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
      // Completely fill the background of the new image with allocated color.
      imagefill($res, 0, 0, $transparency_index);
      // Set the background color for new image to transparent.
      imagecolortransparent($res, $transparency_index);
      // Find number of colors in the images palette.
      $number_colors = imagecolorstotal($im);
      // Convert from true color to palette to fix transparency issues.
      imagetruecolortopalette($res, TRUE, $number_colors);
    }
  }
  imagecopyresampled($res, $im, 0, 0, 0, 0, $width, $height, $info['width'], $info['height']);
  $result = image_gd_close($res, $destination, $info['extension']);

  imagedestroy($res);
  imagedestroy($im);

  return $result;
}
?>