PHP full-featured non-deformation image cropping operation class and usage examples

The example in this article describes the PHP full-featured non-deformation image cropping operation class and usage. Share it with everyone for your reference, the details are as follows:

If you need to crop pictures or generate thumbnails, there is basically no problem with this. All the required functions are in it, and they are all non-deformable.

Here we divide it into four modes:

1. Crop any picture to the specified size, if it exceeds the size, crop it in the play, and maximize the zoom, if it is not stretched enough,
2 . Excessive cropping in the play, but insufficient cropping, do not stretch, that is, only reduce, do not enlarge and crop, which will produce padding, which can be eliminated with png transparency
3. Keep all picture information. No cropping, just scaling, insufficient padding.
4. Keep all picture information. No cropping, only zooming, and no padding if necessary. The generated picture will be the actual effective pixel size. For example, if a picture is 600X600 and now you want to generate 120X100, then the actual effective pixels after scaling are 100X100, so only a 100X100 picture will be generated, and the third This mode generates a size of 120X100, and has fillers.

The code is as follows

<?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(&#39;old.jpg&#39;,&#39;afterCrop.jpg&#39;);
* $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=&#39;&#39;) {
    $this->src_file=$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=&#39;jpg&#39;;
      break;
      case IMAGETYPE_PNG :
      $this->sImage=imagecreatefrompng($this->src_file);
      $this->ext=&#39;png&#39;;
      break;
      case IMAGETYPE_GIF :
      $this->sImage=imagecreatefromgif($this->src_file);
      $this->ext=&#39;gif&#39;;
      break;
      default:
      exit();
    }
  }
  function SaveImage($fileName=&#39;&#39;) {
    $this->dst_file=$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($this->src_type) {
      case IMAGETYPE_JPEG :
      header(&#39;Content-type: image/jpeg&#39;);
      imagejpeg($this->dImage);
      break;
      case IMAGETYPE_PNG :
      header(&#39;Content-type: image/png&#39;);
      imagepng($this->dImage);
      break;
      case IMAGETYPE_GIF :
      header(&#39;Content-type: image/gif&#39;);
      imagegif($this->dImage);
      break;
      default:
      break;
    }
  }
  function SaveAlpha($fileName=&#39;&#39;) {
    $this->dst_file=$fileName ? $fileName . &#39;.png&#39; : $this->dst_file .&#39;.png&#39;;
    imagesavealpha($this->dImage, true);
    imagepng($this->dImage,$this->dst_file);
  }
  function OutAlpha() {
    imagesavealpha($this->dImage, true);
    header(&#39;Content-type: image/png&#39;);
    imagepng($this->dImage);
  }
  function destory() {
    imagedestroy($this->sImage);
    imagedestroy($this->dImage);
  }
  function Crop($dst_width,$dst_height,$mode=1,$dst_file=&#39;&#39;) {
    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
}
?>

I hope this article will be helpful to everyone in PHP programming.

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