PHP-用PHP如何做到将CMYK颜色值和RGB颜色相互转换？

Question

比如：输入CMYK值能够转换成其对应的RGB颜色值，或者输入RGB颜色值能够转换成CMYK值，求对应的算法。

Answer 1

http://www.phpclasses.org/discuss/package/7654/
这个如何？

这个呢：http://stackoverflow.com/questions/3333585/php-hex-to-cmyk

function hex2rgb($hex) {
$color = str_replace('#','',$hex);
$rgb = array('r' => hexdec(substr($color,0,2)),
'g' => hexdec(substr($color,2,2)),
'b' => hexdec(substr($color,4,2)));
return $rgb;
}

function rgb2cmyk($var1,$g=0,$b=0) {
if (is_array($var1)) {
$r = $var1['r'];
$g = $var1['g'];
$b = $var1['b'];
} else {
$r=$var1;
}
$cyan = 255 - $r;
$magenta = 255 - $g;
$yellow = 255 - $b;
$black = min($cyan, $magenta, $yellow);
$cyan = @(($cyan - $black) / (255 - $black)) * 255;
$magenta = @(($magenta - $black) / (255 - $black)) * 255;
$yellow = @(($yellow - $black) / (255 - $black)) * 255;
return array('c' => $cyan / 255,
'm' => $magenta / 255,
'y' => $yellow / 255,
'k' => $black / 255);
}

$color=rgb2cmyk(hex2rgb('#FF0000'));