[PHP]识别图片主色调

一、适用情景：，根据颜色列出相应图片。

二、主程序及API解释：
[php]
<?php

class MajorColor
{
    //参考颜色
    protected $_colors = null;

    //容差
    protected $_tolerance = 80;

    //忽略的颜色
    protected $_ignoreColors = array();

    //支持的图片类型
    protected $_funcs = array('image/png' => 'imagecreatefrompng', 'image/jpeg' => 'imagecreatefromjpeg', 'image/gif' => 'imagecreatefromgif');

    public function __construct(array $colors = null) {
        if(null !== $colors) {
            $this->_colors = $colors;
        }
    }

    public function setColors(array $colors) {
        $this->_colors = $colors;
    }

    public function setTolerance($tolerance) {
        $this->_tolerance = $tolerance;
    }

    public function setIgnoreColors($colors) {
        $this->_ignoreColors = $colors;
    }

    public function _isValidColor($confVal, $val) {
        if(is_array($confVal)) {
            return $val >= $confVal[0] && $val <= $confVal[1];
        } else {
            return $val >= $confVal - $this->_tolerance && $val <= $confVal + $this->_tolerance;
        }
    }

    public function getOrderedColors($pic) {
        $size = getimagesize($pic);
        if(!$size) {
            return false;
        }

        $width = $size[0];
        $height = $size[1];
        $mime = $size['mime'];
        $func = isset($this->_funcs[$mime]) ? $this->_funcs[$mime] : null;
        if(!$func) {
            return false;
        }

        $im = $func($pic);
        if(!$im) {
            return false;
        }

        $total = $width * $height;
        $nums = array();
        for($i = 0; $i < $width; $i++) {
            for($m = 0; $m < $height; $m++) {
                $color_index = imagecolorat($im, $i, $m);
                $color_tran = imagecolorsforindex($im, $color_index);
                $alpha = $color_tran['alpha'];
                unset($color_tran['alpha']);
                if(100 < $alpha || in_array($color_tran, $this->_ignoreColors)) {
                    continue;
                }

                foreach ($this->_colors as $colorid => $color) {
                    if($this->_isValidColor($color['red'], $color_tran['red'])
                        && $this->_isValidColor($color['green'], $color_tran['green'])
                        && $this->_isValidColor($color['blue'], $color_tran['blue'])
                    ) {
                        $nums[$colorid] = isset($nums[$colorid]) ? $nums[$colorid] + 1 : 1;
                    }
                }
            }
        }

        imagedestroy($im);
        arsort($nums);
        return $nums;
    }

    public function getMajorColor($pic) {
        $nums = $this->getOrderedColors($pic);
        $keys = array_keys($nums);
        return $keys[0];
    }
}
1.void setColors(array $colors)
设置可选颜色，即上图中“全部颜色”下的所有颜色(白、灰、黑...)

2.void setTolerance(int $tolerance)
设置容差，比如绿色的RGB值为(0,255,0)，如果设置容差为40，那么-40<=R<

补充：Web开发 , php ,