PHP 图片处理工具类（添加水印与生成缩略图）

=================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;
    }
}

===================ImageTool使用=====================

首先导入ImageTool工具：

require_once ‘ImageTool.class.php‘;

然后实例化ImageTool对象：

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

一、生成压缩图片

$imageTool->compressImage(350, 250, true);//压缩宽度、压缩高度、是否保存
$imageTool->showImage();

二、添加文字水印

$imageTool->addTextmark(‘一拳超人‘, 50, ‘res/micro.ttf‘, true);//内容、尺寸、字体、是否保存
$imageTool->showImage();

三、添加图片水印

$imageTool->addWatermark(‘res/logo.jpeg‘, 100, true);//水印路径、透明度、是否保存
$imageTool->showImage();

仅当做临时图像输出：

$imageTool->addTextmark(‘快捷输出‘, 50, ‘res/micro.ttf‘)->showImage();