php man page for imagelayereffect

IMAGELAYEREFFECT(3)							 1						       IMAGELAYEREFFECT(3)

imagelayereffect - Set the alpha blending flag to use the bundled libgd layering effects

SYNOPSIS
       bool imagelayereffect (resource	$image, int  $effect)

DESCRIPTION
	Set the alpha blending flag to use the bundled libgd layering effects.

PARAMETERS
	      o $
		image -An image resource, returned by one of the image creation functions, such as imagecreatetruecolor(3).

	      o $effect
		- One of the following constants:

		     o IMG_EFFECT_REPLACE - Use pixel replacement (equivalent of passing TRUE to imagealphablending(3))

		     o IMG_EFFECT_ALPHABLEND - Use normal pixel blending (equivalent of passing FALSE to imagealphablending(3))

		     o IMG_EFFECT_NORMAL - Same as IMG_EFFECT_ALPHABLEND.

		     o IMG_EFFECT_OVERLAY  -  Overlay  has the effect that black background pixels will remain black, white background pixels will
		       remain white, but grey background pixels will take the colour of the foreground pixel.

RETURN VALUES
	Returns TRUE on success or FALSE on failure.

EXAMPLES
       Example #1

	      imagelayereffect(3) example

	      <?php
	      // Setup an image
	      $im = imagecreatetruecolor(100, 100);

	      // Set a background
	      imagefilledrectangle($im, 0, 0, 100, 100, imagecolorallocate($im, 220, 220, 220));

	      // Apply the overlay alpha blending flag
	      imagelayereffect($im, IMG_EFFECT_OVERLAY);

	      // Draw two grey ellipses
	      imagefilledellipse($im, 50, 50, 40, 40, imagecolorallocate($im, 100, 255, 100));
	      imagefilledellipse($im, 50, 50, 50, 80, imagecolorallocate($im, 100, 100, 255));
	      imagefilledellipse($im, 50, 50, 80, 50, imagecolorallocate($im, 255, 100, 100));

	      // Output
	      header('Content-type: image/png');

	      imagepng($im);
	      imagedestroy($im);
	      ?>

	      The above example will output something similar to:[NOT DISPLAYABLE MEDIA]Output of example : imagelayereffect()

NOTES
       Note

	      This function requires GD 2.0.1 or later (2.0.28 or later is recommended).

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