Php/docs/function.imagecolorclosestalpha
imagecolorclosestalpha
(PHP 4 >= 4.0.6, PHP 5, PHP 7)
imagecolorclosestalpha — Get the index of the closest color to the specified color + alpha
Description
imagecolorclosestalpha
( resource $image
, int $red
, int $green
, int $blue
, int $alpha
) : int
Returns the index of the color in the palette of the image which
is "closest" to the specified RGB value and
alpha
level.
Parameters
image
- An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
red
- Value of red component.
green
- Value of green component.
blue
- Value of blue component.
alpha
- A value between
0
and127
.0
indicates completely opaque while127
indicates completely transparent.
The colors parameters are integers between 0 and 255 or hexadecimals between 0x00 and 0xFF.
Return Values
Returns the index of the closest color in the palette.
Examples
Example #1 Search for a set of colors in an image
<?php// Start with an image and convert it to a palette-based image$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 matchforeach($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: $result.\n";}imagedestroy($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).
See Also
- imagecolorexactalpha() - Get the index of the specified color + alpha
- imagecolorclosest() - Get the index of the closest color to the specified color
- imagecolorclosesthwb() - Get the index of the color which has the hue, white and blackness