PHP全功能无变形图片裁剪操作类与用法示例

本文实例讲述了PHP全功能无变形图片裁剪操作类与用法。分享给大家供大家参考，具体如下：

如果需要图片裁剪，或生成缩略图，这个基本上没有问题，全部需要的功能都在里面，全部都是无变形的。

这里我们划分为四种模式：

1. 任意图片裁剪到指定大小，超过的，剧中裁剪，并且最大化缩放，不够的拉伸，
2. 超过的剧中裁剪，而不足的，不拉伸，即只缩小，不放大裁剪，会产生补白，可以用png透明度来消除
3. 保留全部图片信息。不裁剪，只缩放，不足的补白。
4. 保留全部图片信息。不裁剪，只缩放，不足的不补白，产生的图片为实际有效像素大小，例如有个图片是600X600 现在要生成 120X100 那么缩放后的实际有效像素为100X100，所以只生成100X100的图片，而第三种模式则生成120X100的大小，并且有补白

代码如下（此处代码通过本站在线工具http://tools.jb51.net/code/jb51_php_format做了格式化处理）:

<?php/*** 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}?>