imagealphablending(3) [php man page]

IMAGEALPHABLENDING(3)							 1						     IMAGEALPHABLENDING(3)

imagealphablending - Set the blending mode for an image

SYNOPSIS

       bool imagealphablending (resource  $image, bool	$blendmode)

DESCRIPTION

       imagealphablending(3)  allows  for two different modes of drawing on truecolor images. In blending mode, the alpha channel component of the
       color supplied to all drawing function, such as imagesetpixel(3) determines how much of the underlying color should  be	allowed  to  shine
       through.  As a result, gd automatically blends the existing color at that point with the drawing color, and stores the result in the image.
       The resulting pixel is opaque. In non-blending mode, the drawing color is copied literally with its alpha  channel  information,  replacing
       the destination pixel. Blending mode is not available when drawing on palette images.

PARAMETERS

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

	      o $blendmode
		- Whether to enable the blending mode or not. On true color images the default value is TRUE otherwise the default value is FALSE

RETURN VALUES

	Returns TRUE on success or FALSE on failure.

EXAMPLES

       Example #1

	      imagealphablending(3) usage example

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

	      // Set alphablending to on
	      imagealphablending($im, true);

	      // Draw a square
	      imagefilledrectangle($im, 30, 30, 70, 70, imagecolorallocate($im, 255, 0, 0));

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

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

NOTES

       Note

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

PHP Documentation Group 												     IMAGEALPHABLENDING(3)

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).

PHP Documentation Group 												       IMAGELAYEREFFECT(3)