imagesavealpha(3) [php man page]

IMAGESAVEALPHA(3)							 1							 IMAGESAVEALPHA(3)

imagesavealpha - Set the flag to save full alpha channel information (as opposed to single-color transparency) when saving PNG images

SYNOPSIS

       bool imagesavealpha (resource  $image, bool  $saveflag)

DESCRIPTION

       imagesavealpha(3) sets the flag to attempt to save full alpha channel information (as opposed to single-color transparency) when saving PNG
       images.

	You have to unset alphablending ( imagealphablending($im, false)), to use it.

	Alpha channel is not supported by all browsers, if you have problem with your browser, try to load your script with an alpha channel  com-
       pliant browser, e.g. latest Mozilla.

PARAMETERS

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

	      o $saveflag
		- Whether to save the alpha channel or not. Default to FALSE.

RETURN VALUES

	Returns TRUE on success or FALSE on failure.

EXAMPLES

       Example #1

	      imagesavealpha(3) example

	      <?php
	      // Load a png image with alpha channels
	      $png = imagecreatefrompng('./alphachannel_example.png');

	      // Do required operations

	      // Turn off alpha blending and set alpha flag
	      imagealphablending($png, false);
	      imagesavealpha($png, true);

	      // Output image to browser
	      header('Content-Type: image/png');

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

NOTES

       Note

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

SEE ALSO

       imagealphablending(3).

PHP Documentation Group 													 IMAGESAVEALPHA(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)