PHP生成图片缩略图类示例

本文实例讲述了PHP生成图片缩略图类。分享给大家供大家参考，具体如下：

class App_image_helper {
  protected $imgFileName;
  protected $imgWidth;
  protected $imgHeight;
  protected $imgMime;
  protected $imgResource;
  static  $imgMineList
    = array(
      'jpeg' => 'image/jpeg',
      'gif' => 'image/gif',
      'png' => 'image/png',
      'wbmp' => 'image/wbmp',
    );
  
  public function __construct($fileName) {
    $this->imgFileName = $fileName;
    list($this->imgWidth, $this->imgHeight, $this->imgMime) = $this->getImageInfo($this->imgFileName);
    $this->imgResource = $this->getImageResource($this->imgFileName);
  }
  
  protected function getImageInfo($fileName) {
    $result = null;
    if ( is_file($fileName) ) {
      $tmpImageInfo = getimagesize($fileName);
      if ( $tmpImageInfo ) {
 $result = array($tmpImageInfo[0], $tmpImageInfo[1], $tmpImageInfo['mime']);
      }
    }
    return $result;
  }
  
  protected function getImageResource($fileName) {
    $image = null;
    if ( is_file($fileName) ) {
      switch ($this->imgMime) {
 case self::$imgMineList['jpeg']:
   $image = imagecreatefromjpeg($fileName);
   break;
 case self::$imgMineList['gif']:
   $image = imagecreatefromgif($fileName);
   break;
 case self::$imgMineList['png']:
   $image = imagecreatefrompng($fileName);
   break;
 case self::$imgMineList['wbmp']:
   $image = imagecreatefromwbmp($fileName);
   break;
 default:
   break;
      }
    }
    return $image;
  }
  
  protected function getSizeByScale($width = 360, $percent = 1) {
    $result = null;
    if ( $this->imgWidth && $this->imgHeight ) {
      if ( $width ) {
 $result = array($width, intval($width * $this->imgHeight / $this->imgWidth));
      } elseif ( $percent ) {
 $result = array(intval($this->imgWidth * $percent), intval($this->imgHeight * $percent));
      }
    }
    return $result;
  }
  
  public function createImage($percentOrWidth = 1, $fileName = null, $quality = 75, $reSample = true) {
    $result = false;
    $fileName ? header('Content-Type: ' . $this->imgMime) : false;
    $size = $this->getSizeByScale(($percentOrWidth <= 1) ? null : $percentOrWidth, $percentOrWidth);
    if ( $size ) {
      $thumb = imagecreatetruecolor($size[0], $size[1]);
      if ( $reSample ) {
 imagecopyresampled($thumb, $this->imgResource, 0, 0, 0, 0, $size[0], $size[1], $this->imgWidth, $this->imgHeight);
      } else {
 imagecopyresized($thumb, $this->imgResource, 0, 0, 0, 0, $size[0], $size[1], $this->imgWidth, $this->imgHeight);
      }
      $result = imagejpeg($thumb, $fileName, $quality);
    }
    return $result;
  }
}

PS：这里再为大家推荐几款比较实用的图片处理工具供大家参考使用：

在线图片转换base64工具：
http://tools.jb51.net/transcoding/img2base64

ICO图标在线生成工具：
http://tools.jb51.net/aideddesign/ico_img

在线Email邮箱图标制作工具：
http://tools.jb51.net/email/emaillogo

在线图片格式转换(jpg/bmp/gif/png)工具：
http://tools.jb51.net/aideddesign/picext

更多关于PHP相关内容感兴趣的读者可查看本站专题：《PHP图形与图片操作技巧汇总》、《PHP基本语法入门教程》、《PHP运算与运算符用法总结》、《php面向对象程序设计入门教程》、《PHP网络编程技巧总结》、《PHP数组(Array)操作技巧大全》、《php字符串(string)用法总结》、《php+mysql数据库操作入门教程》及《php常见数据库操作技巧汇总》

希望本文所述对大家PHP程序设计有所帮助。