protected function _do_watermark(Kohana_Image $image, $offset_x, $offset_y, $opacity)
{
// Convert the Image intance into an Imagick instance
$watermark = new Imagick();
$watermark->readImageBlob($image->render(), $image->file);
if ($watermark->getImageAlphaChannel() !== Imagick::ALPHACHANNEL_ACTIVATE) {
// Force the image to have an alpha channel
$watermark->setImageAlphaChannel(Imagick::ALPHACHANNEL_OPAQUE);
}
if ($opacity < 100) {
// NOTE: Using setImageOpacity will destroy current alpha channels!
$watermark->evaluateImage(Imagick::EVALUATE_MULTIPLY, $opacity / 100, Imagick::CHANNEL_ALPHA);
}
// Match the colorspace between the two images before compositing
// $watermark->setColorspace($this->im->getColorspace());
// Apply the watermark to the image
return $this->im->compositeImage($watermark, Imagick::COMPOSITE_DISSOLVE, $offset_x, $offset_y);
}
/**
* Execute a watermarking.
*
* @param Kohana_Image $image watermarking Kohana_Image
* @param integer $offset_x offset from the left
* @param integer $offset_y offset from the top
* @param integer $opacity opacity of watermark
* @return void
*/
protected function _do_watermark(Kohana_Image $watermark, $offset_x, $offset_y, $opacity)
{
if (empty(Image_GD::$_available_functions[Image_GD::IMAGELAYEREFFECT])) {
throw new ErrorException('This method requires imagelayereffect, which is only available in the bundled version of GD');
}
// Loads image if not yet loaded
$this->_load_image();
// Create the watermark image resource
$overlay = imagecreatefromstring($watermark->render());
imagesavealpha($overlay, TRUE);
// Get the width and height of the watermark
$width = imagesx($overlay);
$height = imagesy($overlay);
if ($opacity < 100) {
// Convert an opacity range of 0-100 to 127-0
$opacity = round(abs($opacity * 127 / 100 - 127));
// Allocate transparent gray
$color = imagecolorallocatealpha($overlay, 127, 127, 127, $opacity);
// The transparent image will overlay the watermark
imagelayereffect($overlay, IMG_EFFECT_OVERLAY);
// Fill the background with the transparent color
imagefilledrectangle($overlay, 0, 0, $width, $height, $color);
}
// Alpha blending must be enabled on the background!
imagealphablending($this->_image, TRUE);
if (imagecopy($this->_image, $overlay, $offset_x, $offset_y, 0, 0, $width, $height)) {
// Destroy the overlay image
imagedestroy($overlay);
}
}
