PHP实现可添加水印与生成缩略图的图片处理工具类

<?php
class imagetool
{
  private $imagepath;//图片路径
  private $outputdir;//输出文件夹
  private $memoryimg;//内存图像
  public function __construct($imagepath, $outputdir = null)
  {
    $this->imagepath = $imagepath;
    $this->outputdir = $outputdir;
    $this->memoryimg = null;
  }
  /**
   * 显示内存中的图片
   * @param $image
   */
  public function showimage()
  {
    if ($this->memoryimg != null) {
      $info = getimagesize($this->imagepath);
      $type = image_type_to_extension($info[2], false);
      header('content-type:' . $info['mime']);
      $funs = "image{$type}";
      $funs($this->memoryimg);
      imagedestroy($this->memoryimg);
      $this->memoryimg = null;
    }
  }
  /**将图片以文件形式保存
   * @param $image
   */
  private function saveimage($image)
  {
    $info = getimagesize($this->imagepath);
    $type = image_type_to_extension($info[2], false);
    $funs = "image{$type}";
    if (empty($this->outputdir)) {
      $funs($image, md5($this->imagepath) . '.' . $type);
    } else {
      $funs($image, $this->outputdir . md5($this->imagepath) . '.' . $type);
    }
  }
  /**
   * 压缩图片
   * @param $width 压缩后宽度
   * @param $height 压缩后高度
   * @param bool $output 是否输出文件
   * @return resource
   */
  public function compressimage($width, $height, $output = false)
  {
    $image = null;
    $info = getimagesize($this->imagepath);
    $type = image_type_to_extension($info[2], false);
    $fun = "imagecreatefrom{$type}";
    $image = $fun($this->imagepath);
    $thumbnail = imagecreatetruecolor($width, $height);
    imagecopyresampled($thumbnail, $image, 0, 0, 0, 0, $width, $height, $info[0], $info[1]);
    imagedestroy($image);
    if ($output) {
      $this->saveimage($thumbnail);
    }
    $this->memoryimg = $thumbnail;
    return $this;
  }
  /**
   * 为图像添加文字标记
   *
   * @param $content 文本内容
   * @param $size 字体大小
   * @param $font 字体样式
   * @param bool $output 是否输出文件
   * @return $this
   */
  public function addtextmark($content, $size, $font, $output = false)
  {
    $info = getimagesize($this->imagepath);
    $type = image_type_to_extension($info[2], false);
    $fun = "imagecreatefrom{$type}";
    $image = $fun($this->imagepath);
    $color = imagecolorallocatealpha($image, 0, 0, 0, 80);
    $posx = imagesx($image) - strlen($content) * $size / 2;
    $posy = imagesy($image) - $size / 1.5;
    imagettftext($image, $size, 0, $posx, $posy, $color, $font, $content);
    if ($output) {
      $this->saveimage($image);
    }
    $this->memoryimg = $image;
    return $this;
  }
  /**
   * 为图片添加水印
   *
   * @param $watermark 水印图片路径
   * @param $alpha 水印透明度(0-100)
   * @param bool $output 是否输出文件
   * @return $this
   */
  public function addwatermark($watermark, $alpha, $output = false)
  {
    $image_info = getimagesize($this->imagepath);
    $image_type = image_type_to_extension($image_info[2], false);
    $image_fun = "imagecreatefrom{$image_type}";
    $image = $image_fun($this->imagepath);
    $mark_info = getimagesize($watermark);
    $mark_type = image_type_to_extension($mark_info[2], false);
    $mark_fun = "imagecreatefrom{$mark_type}";
    $mark = $mark_fun($watermark);
    $posx = imagesx($image) - imagesx($mark);
    $posy = imagesy($image) - imagesy($mark);
    imagecopymerge($image, $mark, $posx, $posy, 0, 0, $mark_info[0], $mark_info[1], $alpha);
    if ($output) {
      $this->saveimage($image);
    }
    $this->memoryimg = $image;
    return $this;
  }
}

require_once 'imagetool.class.php';

$imagetool = new imagetool('img/oppman.jpeg', 'out/');//图片路径、输出文件夹

$imagetool->compressimage(350, 250, true);//压缩宽度、压缩高度、是否保存
$imagetool->showimage();

$imagetool->addtextmark('一拳超人', 50, 'res/micro.ttf', true);//内容、尺寸、字体、是否保存
$imagetool->showimage();

$imagetool->addwatermark('res/logo.jpeg', 100, true);//水印路径、透明度、是否保存
$imagetool->showimage();

$imagetool->addtextmark('快捷输出', 50, 'res/micro.ttf')->showimage();