php man page for imagecolorresolvealpha

IMAGECOLORRESOLVEALPHA(3)						 1						 IMAGECOLORRESOLVEALPHA(3)

imagecolorresolvealpha - Get the index of the specified color + alpha or its closest possible alternative

SYNOPSIS
       int imagecolorresolvealpha (resource  $image, int  $red, int  $green, int  $blue, int  $alpha)

DESCRIPTION
	This function is guaranteed to return a color index for a requested color, either the exact color or the closest possible alternative.

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

	      o $red
		-Value of red component.

	      o $green
		-Value of green component.

	      o $blue
		-Value of blue component.

	      o $alpha
		- A value between 0 and 127.  0 indicates completely opaque while 127 indicates completely transparent.

	The colors parameters are integers between 0 and 255 or hexadecimals between 0x00 and 0xFF.

RETURN VALUES
	Returns a color index.

EXAMPLES
       Example #1

	      Using imagecoloresolvealpha(3) to get colors from an image

	      <?php
	      // Load an image
	      $im = imagecreatefromgif('phplogo.gif');

	      // Get closest colors from the image
	      $colors = array();
	      $colors[] = imagecolorresolvealpha($im, 255, 255, 255, 0);
	      $colors[] = imagecolorresolvealpha($im, 0, 0, 200, 127);

	      // Output
	      print_r($colors);

	      imagedestroy($im);
	      ?>

	      The above example will output something similar to:

	      Array
	      (
		  [0] => 89
		  [1] => 85
	      )

NOTES
       Note

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

SEE ALSO
       imagecolorclosestalpha(3).

PHP Documentation Group 												 IMAGECOLORRESOLVEALPHA(3)