function getMostRepeated($array) { $count = array_count_values($array); arsort($count); $keys = array_keys($count); return $keys[1]; } function fixImg($url) { $img = imagecreatefrompng($url); $with = imagesx($img); $height = imagesy($img); $middle = $height / 2; $colors = array(); for ($i = 0; $i < $with; ++$i) { $color = imagecolorat($img, $i, $middle); $colors[] = $color; } $mainColor = getMostRepeated($colors); for ($x = 0; $x < $with; ++$x) { for ($y = 0; $y < $height; ++$y) { $currentColor = imagecolorat($img, $x, $y); if ($currentColor !== $mainColor) { $white = imagecolorallocate($img, 0xFF, 0xFF, 0xFF); imagesetpixel($img, $x, $y, $white); } } } return $img; } //详情:http://my.oschina.net/gaoshou/blog/126561