PHP实现可添加水印与生成缩略图的图片处理工具类

本文实例讲述了PHP实现可添加水印与生成缩略图的图片处理工具类。分享给大家供大家参考，具体如下：

ImageTool.class.php

<?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;

  }

}