imagecolorclosest(3) [php man page]

IMAGECOLORCLOSEST(3)							 1						      IMAGECOLORCLOSEST(3)

imagecolorclosest - Get the index of the closest color to the specified color

SYNOPSIS

       int imagecolorclosest (resource	$image, int  $red, int	$green, int  $blue)

DESCRIPTION

	Returns the index of the color in the palette of the image which is "closest" to the specified RGB value.

	The  "distance"  between  the  desired color and each color in the palette is calculated as if the RGB values represented points in three-
       dimensional space.

       If you created the image from a file, only colors used in the image are resolved. Colors present only in the palette are not resolved.

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.

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

RETURN VALUES

	Returns the index of the closest color, in the palette of the image, to the specified one

EXAMPLES

       Example #1

	      Search for a set of colors in an image

	      <?php
	      // Start with an image and convert it to a palette-based image
	      $im = imagecreatefrompng('figures/imagecolorclosest.png');
	      imagetruecolortopalette($im, false, 255);

	      // Search colors (RGB)
	      $colors = array(
		  array(254, 145, 154),
		  array(153, 145, 188),
		  array(153, 90, 145),
		  array(255, 137, 92)
	      );

	      // Loop through each search and find the closest color in the palette.
	      // Return the search number, the search RGB and the converted RGB match
	      foreach($colors as $id => $rgb)
	      {
		  $result = imagecolorclosest($im, $rgb[0], $rgb[1], $rgb[2]);
		  $result = imagecolorsforindex($im, $result);
		  $result = "({$result['red']}, {$result['green']}, {$result['blue']})";

		  echo "#$id: Search ($rgb[0], $rgb[1], $rgb[2]); Closest match: $result.
";
	      }

	      imagedestroy($im);
	      ?>

	      The above example will output something similar to:

	      #0: Search (254, 145, 154); Closest match: (252, 150, 148).
	      #1: Search (153, 145, 188); Closest match: (148, 150, 196).
	      #2: Search (153, 90, 145); Closest match: (148, 90, 156).
	      #3: Search (255, 137, 92); Closest match: (252, 150, 92).

SEE ALSO

       imagecolorexact(3), imagecolorclosestalpha(3), imagecolorclosesthwb(3).

PHP Documentation Group 												      IMAGECOLORCLOSEST(3)

IMAGECOLORCLOSESTALPHA(3)						 1						 IMAGECOLORCLOSESTALPHA(3)

imagecolorclosestalpha - Get the index of the closest color to the specified color + alpha

SYNOPSIS

       int imagecolorclosestalpha (resource  $image, int  $red, int  $green, int  $blue, int  $alpha)

DESCRIPTION

	Returns the index of the color in the palette of the image which is "closest" to the specified RGB value and $alpha level.

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 the index of the closest color in the palette.

EXAMPLES

       Example #1

	      Search for a set of colors in an image

	      <?php
	      // Start with an image and convert it to a palette-based image
	      $im = imagecreatefrompng('figures/imagecolorclosest.png');
	      imagetruecolortopalette($im, false, 255);

	      // Search colors (RGB)
	      $colors = array(
		  array(254, 145, 154, 50),
		  array(153, 145, 188, 127),
		  array(153, 90, 145, 0),
		  array(255, 137, 92, 84)
	      );

	      // Loop through each search and find the closest color in the palette.
	      // Return the search number, the search RGB and the converted RGB match
	      foreach($colors as $id => $rgb)
	      {
		  $result = imagecolorclosestalpha($im, $rgb[0], $rgb[1], $rgb[2], $rgb[3]);
		  $result = imagecolorsforindex($im, $result);
		  $result = "({$result['red']}, {$result['green']}, {$result['blue']}, {$result['alpha']})";

		  echo "#$id: Search ($rgb[0], $rgb[1], $rgb[2], $rgb[3]); Closest match: $result.
";
	      }

	      imagedestroy($im);
	      ?>

	      The above example will output something similar to:

	      #0: Search (254, 145, 154, 50); Closest match: (252, 150, 148, 0).
	      #1: Search (153, 145, 188, 127); Closest match: (148, 150, 196, 0).
	      #2: Search (153, 90, 145, 0); Closest match: (148, 90, 156, 0).
	      #3: Search (255, 137, 92, 84); Closest match: (252, 150, 92, 0).

NOTES

       Note

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

SEE ALSO

       imagecolorexactalpha(3), imagecolorclosest(3), imagecolorclosesthwb(3).

PHP Documentation Group 												 IMAGECOLORCLOSESTALPHA(3)