PHP全功能无变形图片裁剪操作类

<?php

$old_img='old.gif'; //原图gif 问题
//downloadimg('http://***');
$new_img='afterCrop.jpg';//新缩略图

if(!file_exists($new_img)){
	$ic=new ImageCrop($old_img,$new_img);
	$ic->Crop(120,80,2);
	$ic->SaveImage();
	//$ic->SaveAlpha();将补白变成透明像素保存
	$ic->destory();
}

showImg($new_img);
/* 
 * php 页面直接输出图片 
 */  
function showImg($img){
    $info = getimagesize($img);  
    $imgExt = image_type_to_extension($info[2], false);  //获取文件后缀  
    $fun = "imagecreatefrom{$imgExt}";  
    $imgInfo = $fun($img);                  //1.由文件或 URL 创建一个新图象。如:imagecreatefrompng ( string $filename )  
    //$mime = $info['mime'];  
    $mime = image_type_to_mime_type(exif_imagetype($img)); //获取图片的 MIME 类型  
    header('Content-Type:'.$mime);  
    $quality = 100;  
    if($imgExt == 'png') $quality = 9;      //输出质量,JPEG格式(0-100),PNG格式(0-9)  
    $getImgInfo = "image{$imgExt}";  
    $getImgInfo($imgInfo, null, $quality);  //2.将图像输出到浏览器或文件。如: imagepng ( resource $image )  
    imagedestroy($imgInfo);  
}
//下载远程图片
function downloadimg($url, $path = '' ,$extn = '.png'){
	$ch = curl_init();
	curl_setopt($ch, CURLOPT_URL, $url);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
	$file = curl_exec($ch);
	curl_close($ch);
	$filename = pathinfo($url, PATHINFO_BASENAME);
	$ext = strrchr($filename,'.');//把图片名当做字符串来处理，那么判断图片格式的也就是变成了查找“.”号的字符串
	if(!$ext){
		$ext = $extn;
		$filename .= $ext;
	}
	
	if(!$path){
		$path=tempnam(sys_get_temp_dir(), 'dimg');//php保存到临时文件夹
		rename($path, $path .= $filename);
	}
	
	$resource = fopen($path, 'a');
	fwrite($resource, $file);
	fclose($resource);
	return $path;
}

/**
* Author : smallchicken
* mode 1 : 强制裁剪，生成图片严格按照需要，不足放大，超过裁剪，图片始终铺满
* mode 2 : 和1类似，但不足的时候 不放大 会产生补白，可以用png消除。
* mode 3 : 只缩放，不裁剪，保留全部图片信息，会产生补白，
* mode 4 : 只缩放，不裁剪，保留全部图片信息，生成图片大小为最终缩放后的图片有效信息的实际大小，不产生补白
* 默认补白为白色，如果要使补白成透明像素，请使用SaveAlpha()方法代替SaveImage()方法
*
* 调用方法：
*
* $ic=new ImageCrop('old.jpg','afterCrop.jpg');
* $ic->Crop(120,80,2);
* $ic->SaveImage();
*    //$ic->SaveAlpha();将补白变成透明像素保存
* $ic->destory();
*
*
*/
class ImageCrop {
  var $sImage;
  var $dImage;
  var $src_file;
  var $dst_file;
  var $src_width;
  var $src_height;
  var $src_ext;
  var $src_type;
  function ImageCrop($src_file,$dst_file='') {
    $this->src_file=$src_file;
    $this->dst_file=$dst_file;
    $this->LoadImage();
  }
  function SetSrcFile($src_file) {
    $this->src_file=$src_file;
  }
  function SetDstFile($dst_file) {
    $this->dst_file=$dst_file;
  }
  function LoadImage() {
    list($this->src_width, $this->src_height, $this->src_type) = getimagesize($this->src_file);
    switch($this->src_type) {
      case IMAGETYPE_JPEG :
      $this->sImage=imagecreatefromjpeg($this->src_file);
      $this->ext='jpg';
      break;
      case IMAGETYPE_PNG :
      $this->sImage=imagecreatefrompng($this->src_file);
      $this->ext='png';
      break;
      case IMAGETYPE_GIF :
      $this->sImage=imagecreatefromgif($this->src_file);
      $this->ext='gif';
      break;
      default:
      exit();
    }
  }
  function SaveImage($fileName='') {
    $this->dst_file=$fileName ? $fileName : $this->dst_file;
    switch($this->src_type) {
      case IMAGETYPE_JPEG :
      imagejpeg($this->dImage,$this->dst_file,100);
      break;
      case IMAGETYPE_PNG :
      imagepng($this->dImage,$this->dst_file);
      break;
      case IMAGETYPE_GIF :
      imagegif($this->dImage,$this->dst_file);
      break;
      default:
      break;
    }
  }
  function OutImage() {
    switch($this->src_type) {
      case IMAGETYPE_JPEG :
      header('Content-type: image/jpeg');
      imagejpeg($this->dImage);
      break;
      case IMAGETYPE_PNG :
      header('Content-type: image/png');
      imagepng($this->dImage);
      break;
      case IMAGETYPE_GIF :
      header('Content-type: image/gif');
      imagegif($this->dImage);
      break;
      default:
      break;
    }
  }
  function SaveAlpha($fileName='') {
    $this->dst_file=$fileName ? $fileName . '.png' : $this->dst_file .'.png';
    imagesavealpha($this->dImage, true);
    imagepng($this->dImage,$this->dst_file);
  }
  function OutAlpha() {
    imagesavealpha($this->dImage, true);
    header('Content-type: image/png');
    imagepng($this->dImage);
  }
  function destory() {
    imagedestroy($this->sImage);
    imagedestroy($this->dImage);
  }
  function Crop($dst_width,$dst_height,$mode=1,$dst_file='') {
    if($dst_file) $this->dst_file=$dst_file;
    $this->dImage = imagecreatetruecolor($dst_width,$dst_height);
    $bg = imagecolorallocatealpha($this->dImage,255,255,255,127);
    imagefill($this->dImage, 0, 0, $bg);
    imagecolortransparent($this->dImage,$bg);
    $ratio_w=1.0 * $dst_width / $this->src_width;
    $ratio_h=1.0 * $dst_height / $this->src_height;
    $ratio=1.0;
    switch($mode) {
      case 1:    // always crop
      if( ($ratio_w < 1 && $ratio_h < 1) || ($ratio_w > 1 && $ratio_h > 1)) {
        $ratio = $ratio_w < $ratio_h ? $ratio_h : $ratio_w;
        $tmp_w = (int)($dst_width / $ratio);
        $tmp_h = (int)($dst_height / $ratio);
        $tmp_img=imagecreatetruecolor($tmp_w , $tmp_h);
        $src_x = (int) (($this->src_width-$tmp_w)/2) ;
        $src_y = (int) (($this->src_height-$tmp_h)/2) ;
        imagecopy($tmp_img, $this->sImage, 0,0,$src_x,$src_y,$tmp_w,$tmp_h);
        imagecopyresampled($this->dImage,$tmp_img,0,0,0,0,$dst_width,$dst_height,$tmp_w,$tmp_h);
        imagedestroy($tmp_img);
      } else {
        $ratio = $ratio_w < $ratio_h ? $ratio_h : $ratio_w;
        $tmp_w = (int)($this->src_width * $ratio);
        $tmp_h = (int)($this->src_height * $ratio);
        $tmp_img=imagecreatetruecolor($tmp_w ,$tmp_h);
        imagecopyresampled($tmp_img,$this->sImage,0,0,0,0,$tmp_w,$tmp_h,$this->src_width,$this->src_height);
        $src_x = (int)($tmp_w - $dst_width) / 2 ;
        $src_y = (int)($tmp_h - $dst_height) / 2 ;
        imagecopy($this->dImage, $tmp_img, 0,0,$src_x,$src_y,$dst_width,$dst_height);
        imagedestroy($tmp_img);
      }
      break;
      case 2:    // only small
      if($ratio_w < 1 && $ratio_h < 1) {
        $ratio = $ratio_w < $ratio_h ? $ratio_h : $ratio_w;
        $tmp_w = (int)($dst_width / $ratio);
        $tmp_h = (int)($dst_height / $ratio);
        $tmp_img=imagecreatetruecolor($tmp_w , $tmp_h);
        $src_x = (int) ($this->src_width-$tmp_w)/2 ;
        $src_y = (int) ($this->src_height-$tmp_h)/2 ;
        imagecopy($tmp_img, $this->sImage, 0,0,$src_x,$src_y,$tmp_w,$tmp_h);
        imagecopyresampled($this->dImage,$tmp_img,0,0,0,0,$dst_width,$dst_height,$tmp_w,$tmp_h);
        imagedestroy($tmp_img);
      } elseif($ratio_w > 1 && $ratio_h > 1) {
        $dst_x = (int) abs($dst_width - $this->src_width) / 2 ;
        $dst_y = (int) abs($dst_height -$this->src_height) / 2;
        imagecopy($this->dImage, $this->sImage,$dst_x,$dst_y,0,0,$this->src_width,$this->src_height);
      } else {
        $src_x=0;
        $dst_x=0;
        $src_y=0;
        $dst_y=0;
        if(($dst_width - $this->src_width) < 0) {
          $src_x = (int) ($this->src_width - $dst_width)/2;
          $dst_x =0;
        } else {
          $src_x =0;
          $dst_x = (int) ($dst_width - $this->src_width)/2;
        }
        if( ($dst_height -$this->src_height) < 0) {
          $src_y = (int) ($this->src_height - $dst_height)/2;
          $dst_y = 0;
        } else {
          $src_y = 0;
          $dst_y = (int) ($dst_height - $this->src_height)/2;
        }
        imagecopy($this->dImage, $this->sImage,$dst_x,$dst_y,$src_x,$src_y,$this->src_width,$this->src_height);
      }
      break;
      case 3:    // keep all image size and create need size
      if($ratio_w > 1 && $ratio_h > 1) {
        $dst_x = (int)(abs($dst_width - $this->src_width )/2) ;
        $dst_y = (int)(abs($dst_height- $this->src_height)/2) ;
        imagecopy($this->dImage, $this->sImage, $dst_x,$dst_y,0,0,$this->src_width,$this->src_height);
      } else {
        $ratio = $ratio_w > $ratio_h ? $ratio_h : $ratio_w;
        $tmp_w = (int)($this->src_width * $ratio);
        $tmp_h = (int)($this->src_height * $ratio);
        $tmp_img=imagecreatetruecolor($tmp_w ,$tmp_h);
        imagecopyresampled($tmp_img,$this->sImage,0,0,0,0,$tmp_w,$tmp_h,$this->src_width,$this->src_height);
        $dst_x = (int)(abs($tmp_w -$dst_width )/2) ;
        $dst_y = (int)(abs($tmp_h -$dst_height)/2) ;
        imagecopy($this->dImage, $tmp_img, $dst_x,$dst_y,0,0,$tmp_w,$tmp_h);
        imagedestroy($tmp_img);
      }
      break;
      case 4:    // keep all image but create actually size
      if($ratio_w > 1 && $ratio_h > 1) {
        $this->dImage = imagecreatetruecolor($this->src_width,$this->src_height);
        imagecopy($this->dImage, $this->sImage,0,0,0,0,$this->src_width,$this->src_height);
      } else {
        $ratio = $ratio_w > $ratio_h ? $ratio_h : $ratio_w;
        $tmp_w = (int)($this->src_width * $ratio);
        $tmp_h = (int)($this->src_height * $ratio);
        $this->dImage = imagecreatetruecolor($tmp_w ,$tmp_h);
        imagecopyresampled($this->dImage,$this->sImage,0,0,0,0,$tmp_w,$tmp_h,$this->src_width,$this->src_height);
      }
      break;
    }
  }
  // end Crop
}