php生成缩略图，加水印类

这个一个简单的GD库操作

<?php/**** 燕十八 公益PHP讲堂 论  坛: http://www.zixue.it 微  博: http://weibo.com/Yshiba YY频道: 88354001 ****//*** 想操作图片 先得把图片的大小,类型信息得到 水印:就是把指定的水印复制到目标上,并加透明效果 缩略图:就是把大图片复制到小尺寸画面上 ***/class ImageTool {// imageInfo 分析图片的信息// return array()public static function imageInfo($image) {// 判断图片是否存在if (!file_exists($image)) {return false;}$info = getimagesize($image);if ($info == false) {return false;}// 此时info分析出来,是一个数组$img['width'] = $info[0];$img['height'] = $info[1];$img['ext'] = substr($info['mime'], strpos($info['mime'], '/') + 1);return $img;}/* 加水印功能 parm String $dst 等操作图片 parm String $water 水印小图 parm String $save,不填则默认替换原始图 */public static function water($dst, $water, $save = NULL, $pos = 2, $alpha = 50) {// 先保证2个图片存在if (!file_exists($dst) || !file_exists($water)) {return false;}// 首先保证水印不能比待操作图片还大$dinfo = self::imageInfo($dst);$winfo = self::imageInfo($water);if ($winfo['height'] > $dinfo['height'] || $winfo['width'] > $dinfo['width']) {return false;}// 两张图,读到画布上! 但是图片可能是png,可能是jpeg,用什么函数读?$dfunc = 'imagecreatefrom' . $dinfo['ext'];$wfunc = 'imagecreatefrom' . $winfo['ext'];if (!function_exists($dfunc) || !function_exists($wfunc)) {return false;}// 动态加载函数来创建画布$dim = $dfunc($dst);// 创建待操作的画布$wim = $wfunc($water);// 创建水印画布// 根据水印的位置 计算粘贴的坐标switch($pos) {case 0 :// 左上角$posx = 0;$posy = 0;break;case 1 :// 右上角$posx = $dinfo['width'] - $winfo['width'];$posy = 0;break;case 3 :// 左下角$posx = 0;$posy = $dinfo['height'] - $winfo['height'];break;default :$posx = $dinfo['width'] - $winfo['width'];$posy = $dinfo['height'] - $winfo['height'];}// 加水印imagecopymerge($dim, $wim, $posx, $posy, 0, 0, $winfo['width'], $winfo['height'], $alpha);// 保存if (!$save) {$save = $dst;unlink($dst);// 删除原图}$createfunc = 'image' . $dinfo['ext'];$createfunc($dim, $save);imagedestroy($dim);imagedestroy($wim);return true;}/** thumb 生成缩略图 等比例缩放,两边留白 **/public static function thumb($dst, $save = NULL, $width = 200, $height = 200) {// 首先判断待处理的图片存不存在$dinfo = self::imageInfo($dst);if ($dinfo == false) {return false;}// 计算缩放比例$calc = min($width / $dinfo['width'], $height / $dinfo['height']);// 创建原始图的画布$dfunc = 'imagecreatefrom' . $dinfo['ext'];$dim = $dfunc($dst);// 创建缩略画布$tim = imagecreatetruecolor($width, $height);// 创建白色填充缩略画布$white = imagecolorallocate($tim, 255, 255, 255);// 填充缩略画布imagefill($tim, 0, 0, $white);// 复制并缩略$dwidth = (int)$dinfo['width'] * $calc;$dheight = (int)$dinfo['height'] * $calc;$paddingx = (int)($width - $dwidth) / 2;$paddingy = (int)($height - $dheight) / 2;imagecopyresampled($tim, $dim, $paddingx, $paddingy, 0, 0, $dwidth, $dheight, $dinfo['width'], $dinfo['height']);// 保存图片if (!$save) {$save = $dst;unlink($dst);}$createfunc = 'image' . $dinfo['ext'];$createfunc($tim, $save);imagedestroy($dim);imagedestroy($tim);return true;}}// print_r(ImageTool::imageInfo('./home.jpg'));/* echo ImageTool::water('./home.jpg','./smallfeng.png','home1.jpg',0)?'OK':'FAIL'; echo ImageTool::water('./home.jpg','./smallfeng.png','home2.jpg',1)?'OK':'FAIL'; echo ImageTool::water('./home.jpg','./smallfeng.png','home3.jpg',2)?'OK':'FAIL'; echo ImageTool::water('./home.jpg','./smallfeng.png','home4.jpg',3)?'OK':'FAIL'; */