function image_gd_create_tmp

Create a truecolor image preserving transparency from a provided image.

Parameters

$image: An image object.

$width: The new width of the new image, in pixels.

$height: The new height of the new image, in pixels.

Return value

A GD image handle.

Related topics

Image toolkits
Functions for image file manipulations.
3 calls to image_gd_create_tmp()
image_gd_crop in drupal/modules/system/image.gd.inc
Crop an image using the GD toolkit.
image_gd_load in drupal/modules/system/image.gd.inc
GD helper function to create an image resource from a file.
image_gd_resize in drupal/modules/system/image.gd.inc
Scale an image to the specified size using GD.

File

drupal/modules/system/image.gd.inc, line 337
GD2 toolkit for image manipulation within Drupal.

Code

function image_gd_create_tmp(stdClass $image, $width, $height) {
  $res = imagecreatetruecolor($width, $height);
  if ($image->info['extension'] == 'gif') {

    // Find out if a transparent color is set, will return -1 if no
    // transparent color has been defined in the image.
    $transparent = imagecolortransparent($image->resource);
    if ($transparent >= 0) {

      // Find out the number of colors in the image palette. It will be 0 for
      // truecolor images.
      $palette_size = imagecolorstotal($image->resource);
      if ($palette_size == 0 || $transparent < $palette_size) {

        // Set the transparent color in the new resource, either if it is a
        // truecolor image or if the transparent color is part of the palette.
        // Since the index of the transparency color is a property of the
        // image rather than of the palette, it is possible that an image
        // could be created with this index set outside the palette size (see
        // http://stackoverflow.com/a/3898007).
        $transparent_color = imagecolorsforindex($image->resource, $transparent);
        $transparent = imagecolorallocate($res, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);

        // Flood with our new transparent color.
        imagefill($res, 0, 0, $transparent);
        imagecolortransparent($res, $transparent);
      }
      else {
        imagefill($res, 0, 0, imagecolorallocate($res, 255, 255, 255));
      }
    }
  }
  elseif ($image->info['extension'] == 'png') {
    imagealphablending($res, FALSE);
    $transparency = imagecolorallocatealpha($res, 0, 0, 0, 127);
    imagefill($res, 0, 0, $transparency);
    imagealphablending($res, TRUE);
    imagesavealpha($res, TRUE);
  }
  else {
    imagefill($res, 0, 0, imagecolorallocate($res, 255, 255, 255));
  }
  return $res;
}