PHP - 将RGB值转换为CMYK百分比

时间:2012-03-22 06:43:10

标签: php

我使用这个PHP代码获取RGB值

<?php
$im = imagecreatefrompng("img/t4.png");
$rgb = imagecolorat($im, 15, 15);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
?>

我还需要CMYK百分比

有人可以给我一些索引线。

感谢。

1 个答案:

答案 0 :(得分:2)

<?
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);
}

$color=rgb2cmyk(hex2rgb('#FF0000')); 
pdf_setcolor($pdf, "both", "cmyk", $color['c'], $color['m'], $color['y'], $color['k']);
?>