1、压缩代码为借鉴
<?phpnamespace img;/*** 图片压缩类:通过缩放来压缩。* 如果要保持源图比例,把参数$percent保持为1即可。* 即使原比例压缩,也可大幅度缩小。数码相机4M图片。也可以缩为700KB左右。如果缩小比例,则体积会更小。** 结果:可保存、可直接显示。*/class compress{private $src;private $image;private $imageinfo;private $percent = 0.5;/*** 图片压缩* @param $src 源图* @param float $percent 压缩比例*/public function __construct($src, $percent=1){$this->src = $_SERVER[‘DOCUMENT_ROOT’].$src;$this->percent = $percent;}/** 高清压缩图片* @param string $saveName 提供图片名(可不带扩展名,用源图扩展名)用于保存。或不提供文件名直接显示*/public function compressImg($saveName=”){$this->_openImage();if(!empty($saveName)) $this->_saveImage($saveName); //保存else $this->_showImage();}/*** 内部:打开图片*/private function _openImage(){list($width, $height, $type, $attr) = getimagesize($this->src);$this->imageinfo = array(‘width’=>$width,‘height’=>$height,‘type’=>image_type_to_extension($type,false),‘attr’=>$attr);$fun = “imagecreatefrom”.$this->imageinfo[‘type’];$this->image = $fun($this->src);$this->_thumpImage();}/*** 内部:操作图片*/private function _thumpImage(){$new_width = $this->imageinfo[‘width’] * $this->percent;$new_height = $this->imageinfo[‘height’] * $this->percent;$image_thump = imagecreatetruecolor($new_width,$new_height);//将原图复制带图片载体上面,并且按照一定比例压缩,极大的保持了清晰度imagecopyresampled($image_thump,$this->image,0,0,0,0,$new_width,$new_height,$this->imageinfo[‘width’],$this->imageinfo[‘height’]);imagedestroy($this->image);$this->image = $image_thump;}/*** 输出图片:保存图片则用saveImage()*/private function _showImage(){header(‘Content-Type: image/’.$this->imageinfo[‘type’]);$funcs = “image”.$this->imageinfo[‘type’];$funcs($this->image);}/*** 保存图片到硬盘:* @param string $dstImgName 1、可指定字符串不带后缀的名称,使用源图扩展名 。2、直接指定目标图片名带扩展名。*/private function _saveImage($dstImgName){if(empty($dstImgName)) return false;$allowImgs = [‘.jpg’, ‘.jpeg’, ‘.png’, ‘.bmp’, ‘.wbmp’,’.gif’]; //如果目标图片名有后缀就用目标图片扩展名 后缀,如果没有,则用源图的扩展名$dstExt = strrchr($dstImgName ,”.”);$sourseExt = strrchr($this->src ,”.”);if(!empty($dstExt)) $dstExt =strtolower($dstExt);if(!empty($sourseExt)) $sourseExt =strtolower($sourseExt);//有指定目标名扩展名if(!empty($dstExt) && in_array($dstExt,$allowImgs)){$dstName = $dstImgName;}elseif(!empty($sourseExt) && in_array($sourseExt,$allowImgs)){$dstName = $dstImgName.$sourseExt;}else{$dstName = $dstImgName.$this->imageinfo[‘type’];}$funcs = “image”.$this->imageinfo[‘type’];$dstName = $_SERVER[‘DOCUMENT_ROOT’].$dstName;$funcs($this->image,$dstName);}/*** 销毁图片*/public function __destruct(){// imagedestroy($this->image);}}2、递归至300kb//递归图片压缩至小于300kpublic function compressimg($filesize,$source,$dst_img,$file_url,$ori_imginfo){$file_min_size = 307200;//300kif($filesize>(1 * 1024 * 1024) && $filesize<=(10 * 1024 * 1024)){$percent = 0.2;}if($filesize>$file_min_size && $filesize<(1 * 1024 * 1024)){$percent = 0.8;}$image = (new compress($source,$percent))->compressImg($dst_img);$size = filesize($_SERVER[‘DOCUMENT_ROOT’].$dst_img);unlink($_SERVER[‘DOCUMENT_ROOT’].$source);if($size>$file_min_size){$new_filename = date(‘Ymd’) . DS . md5(microtime(true));$new_filename .= ‘.’ . pathinfo($ori_imginfo[‘name’], PATHINFO_EXTENSION);$new_dst_img = str_replace(‘//’,’/’,$file_url.$new_filename);return $this->compressimg($size,$dst_img,$new_dst_img,$file_url,$ori_imginfo);}else{return $dst_img;}}3、调用if($_FILES[‘file’][‘size’]>307200){$ori_imginfo = $info->getInfo($filename);$new_filename = date(‘Ymd’) . DS . md5(microtime(true));$new_filename .= ‘.’ . pathinfo($ori_imginfo[‘name’], PATHINFO_EXTENSION);$source = str_replace(‘//’,’/’,$url);$dst_img = str_replace(‘//’,’/’,$file_url.$new_filename);$url = $this->compressimg($_FILES[‘file’][‘size’],$source,$dst_img,$file_url,$ori_imginfo);$url = str_replace(‘\\’,’/’,$url);}1M到10M之间按宽高分别20%的压缩比例进行压缩,当压缩到大于300kb小于1M以内,为防止压缩过小,此时按照宽高分别80%的比例进行压缩,直至到300k以内;比例不是固定,可以根据实际情况进行相应的调节