给图片添加水印，其实就是把原来的图片和水印添加在一起，下面小编把最近整理的资料分享给大家。

php对图片文件的操作主要是利用GD库扩展。当我们频繁利用php对图片进行操作时，会自然封装很多函数，否则会写太多重复的代码。当有很多对图片的相关函数的时候，我们可以考虑将这些函数也整理一下，因而就有了封装成类的想法。

操作图片主要历经四个步骤：

第一步：打开图片

第二步：操作图片

第三步：输出图片

第四步：销毁图片

1,3,4三个步骤每次都要写，每次又都差不多。真正需要变通的只有操作图片的这一步骤了。操作图片又往往通过1或多个主要的GD函数来完成。

本文封装类里面的四种方法，文字水印（imagettftext()），图片水印（imagecopymerge()），图片压缩，图片剪切(imagecopyresampled())，其余的常用GD函数便不赘述。

直接上代码：

<?php class Image { private $info; private $image; public $type; public function __construct($src) { $this->info=getimagesize($src); $this->type=image_type_to_extension($this->info['2'],false); $fun="imagecreatefrom{$this->type}"; $this->image=$fun($src); } /** * 文字水印 * @param [type] $font 字体 * @param [type] $content 内容 * @param [type] $size 文字大小 * @param [type] $col 文字颜色（四元数组） * @param array $location 位置 * @param integer $angle 倾斜角度 * @return [type] */ public function fontMark($font,$content,$size,$col,$location,$angle=0){ $col=imagecolorallocatealpha($this->image, $col['0'], $col['1'], $col['2'],$col['3']); imagettftext($this->image, $size, $angle, $location['0'], $location['1'], $col,$font,$content); } /** * 图片水印 * @param [type] $imageMark 水印图片地址 * @param [type] $dst 水印图片在原图片中的位置 * @param [type] $pct 透明度 * @return [type] */ public function imageMark($imageMark,$dst,$pct){ $info2=getimagesize($imageMark); $type=image_type_to_extension($info2['2'],false); $func2="imagecreatefrom".$type; $water=$func2($imageMark); imagecopymerge($this->image, $water, $dst[0], $dst[1], 0, 0, $info2['0'], $info2['1'], $pct); imagedestroy($water); } /** * 压缩图片 * @param [type] $thumbSize 压缩图片大小 * @return [type] [description] */ public function thumb($thumbSize){ $imageThumb=imagecreatetruecolor($thumbSize[0], $thumbSize[1]); imagecopyresampled($imageThumb, $this->image, 0, 0, 0, 0, $thumbSize[0], $thumbSize[1], $this->info['0'], $this->info['1']); imagedestroy($this->image); $this->image=$imageThumb; } /** * 裁剪图片 * @param [type] $cutSize 裁剪大小 * @param [type] $location 裁剪位置 * @return [type] [description] */ public function cut($cutSize,$location){ $imageCut=imagecreatetruecolor($cutSize[0],$cutSize[1]); imagecopyresampled($imageCut, $this->image, 0, 0, $location[0], $location[1],$cutSize[0],$cutSize[1],$cutSize[0],$cutSize[1]); imagedestroy($this->image); $this->image=$imageCut; } /** * 展现图片 * @return [type] [description] */ public function show(){ header("content-type:".$this->info['mime']); $funn="image".$this->type; $funn($this->image); } /** * 保存图片 * @param [type] $newname 新图片名 * @return [type] [description] */ public function save($newname){ header("content-type:".$this->info['mime']); $funn="image".$this->type; $funn($this->image,$newname.'.'.$this->type); } public function __destruct(){ imagedestroy($this->image); } } ?>

如果还需要其他操作，只需要再往这个类里面添加就好啦~~

给图片添加水印代码：

先看文件check_image_addwatermark.php代码

<?php //修改图片效果 $db = mysql_connect('localhost','root','Ctrip07185419') or die('can not connect to database'); mysql_select_db('moviesite',$db) or die(mysql_error($db)); //上传文件的路径 $dir = 'D:Seriousphpdevtestimages'; //设置环境变量 putenv('GDFONTPATH='.'C:WindowsFonts'); $font = "arial"; //upload_image.php页面传递过来的参数，如果是上传图片 if($_POST['submit'] == 'Upload') { if($_FILES['uploadfile']['error'] != UPLOAD_ERR_OK) { switch($_FILES['uploadfile']['error']) { case UPLOAD_ERR_INI_SIZE: die('The uploaded file exceeds the upload_max_filesize directive'); break; case UPLOAD_ERR_FORM_SIZE: die('The upload file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form'); break; case UPLOAD_ERR_PARTIAL: die('The uploaded file was only partially uploaded'); break; case UPLOAD_ERR_NO_FILE: die('No file was uploaded'); break; case UPLOAD_ERR_NO_TMP_DIR: die('The server is missing a temporary folder'); break; case UPLOAD_ERR_CANT_WRITE: die('The server fail to write the uploaded file to the disk'); break; case UPLOAD_ERR_EXTENSION: die('The upload stopped by extension'); break; } } $image_caption = $_POST['caption']; $image_username = $_POST['username']; $image_date = date('Y-m-d'); list($width,$height,$type,$attr) = getimagesize($_FILES['uploadfile']['tmp_name']); $error = 'The file you upload is not a supported filetype'; switch($type) { case IMAGETYPE_GIF: $image = imagecreatefromgif($_FILES['uploadfile']['tmp_name']) or die($error); break; case IMAGETYPE_JPEG: $image = imagecreatefromjpeg($_FILES['uploadfile']['tmp_name']) or die($error); break; case IMAGETYPE_PNG: $image = imagecreatefrompng($_FILES['uploadfile']['tmp_name']) or die($error); break; default: break; } $query = 'insert into images(image_caption,image_username,image_date) values("'.$image_caption.'" , "'.$image_username.'","'.$image_date.'")'; $result = mysql_query($query,$db) or die(mysql_error($db)); $last_id = mysql_insert_id(); // $imagename = $last_id.'.jpg'; // imagejpeg($image,$dir.'/'.$imagename); // imagedestroy($image); $image_id = $last_id; imagejpeg($image , $dir.'/'.$image_id.'.jpg'); imagedestroy($image); } else //如果图片已经上传，则从数据库中取图片名字 { $query = 'select image_id,image_caption,image_username,image_date from images where image_id='.$_POST['id']; $result = mysql_query($query,$db) or die(mysql_error($db)); extract(mysql_fetch_assoc($result)); list($width,$height,$type,$attr) = getimagesize($dir.'/'.$image_id.'.jpg'); } //如果是保存图片 if($_POST['submit'] == 'Save') { if(isset($_POST['id']) && ctype_digit($_POST['id']) && file_exists($dir.'/'.$_POST['id'].'.jpg')) { $image = imagecreatefromjpeg($dir.'/'.$_POST['id'].'.jpg'); } else { die('invalid image specified'); } $effect = (isset($_POST['effect'])) ? $_POST['effect'] : -1; switch($effect) { case IMG_FILTER_NEGATE: imagefilter($image , IMG_FILTER_NEGATE); //将图像中所有颜色反转 break; case IMG_FILTER_GRAYSCALE: imagefilter($image , IMG_FILTER_GRAYSCALE); //将图像转换为灰度的 break; case IMG_FILTER_EMBOSS: imagefilter($image , IMG_FILTER_EMBOSS); //使图像浮雕化 break; case IMG_FILTER_GAUSSIAN_BLUR: imagefilter($image , IMG_FILTER_GAUSSIAN_BLUR); //用高斯算法模糊图像 break; } if(isset($_POST['emb_caption'])) { imagettftext($image , 12 , 0 , 20 , 20 , 0 , $font , $image_caption); } if(isset($_POST['emb_logo'])) { //获取水印图片的尺寸并创建水印 list($wmk_width , $wmk_height) = getimagesize('images/logo.png'); $x = ($width-$wmk_width) / 2; $y = ($height-$wmk_height)/2; $wmk = imagecreatefrompng('images/logo.png'); //把水印图片和原图片合并在一起 imagecopymerge($image , $wmk , $x , $y , 0 , 0 , $wmk_width , $wmk_height , 20); //清除水印图片 imagedestroy($wmk); } imagejpeg($image , $dir.'/'.$_POST['id'].'.jpg' , 100); ?> <html> <head> <title>Here is your pic!</title> </head> <body> <h1>Your image has been saved!</h1> <img src="images/<?php echo $_POST['id'];" /> </body> </html> <?php } else { ?> <html> <head> <title>Here is your pic!</title> </head> <body> <h1>So how does it feel to be famous?</h1> <p>Here is the picture you just uploaded to your servers:</p> <> </body> </html> <?php if($_POST['submit'] == 'Upload') { $imagename = 'images/'.$image_id.'.jpg'; } else { $imagename = 'image_effect.php?id='.$image_id.'&e='.$_POST['effect']; if(isset($_POST['emb_caption'])) { $imagename .= '&capt='.urlencode($image_caption); } if(isset($_POST['emb_logo'])) { $imagename .= '&logo=1'; } } ?> <img src="<?php echo $imagename;"float:left;" alt="" /> <table> <tr> <td>Image save as:</td> <td><?php $image_id?></td> </tr> <tr> <td>Height:</td> <td><?php echo $height;?></td> </tr> <tr> <td>Widht:</td> <td><?php echo $width;?></td> </tr> <tr> <td>Upload date:</td> <td><?php echo $image_date;?></td> </tr> </table> <p>You may apply a special effect to your image from the list of option below. Note:saving an image with any of the filters applied <em>can be undone</em> </p> <form action="<?php echo $_SERVER['PHP_SELF'];"post"> <div> <input type="hidden" name="id" value="<?php echo $image_id;"/> Filter:<select name="effect" id=""> <option value="-1">None</option> <?php echo '<option value="'.IMG_FILTER_GRAYSCALE.'" '; if(isset($_POST['effect']) && $_POST['effect'] == IMG_FILTER_GRAYSCALE) { echo 'selected="selected"'; } echo ' >Black and white</option>'; echo '<option value="'.IMG_FILTER_GAUSSIAN_BLUR.'"'; if(isset($_POST['effect']) && $_POST['effect'] == IMG_FILTER_GAUSSIAN_BLUR) { echo ' selected="selected"'; } echo '>Blur</option>'; echo '<option value="'.IMG_FILTER_EMBOSS.'"'; if(isset($_POST['effect']) && $_POST['effect'] == IMG_FILTER_EMBOSS) { echo 'selected="selected"'; } echo '>Emboss</option>'; echo '<option value="'.IMG_FILTER_NEGATE.'"'; if(isset($_POST['effect']) && $_POST['effect'] == IMG_FILTER_NEGATE) { echo 'selected="selected"'; } echo '>Negative</option>'; ?> </select><br /> <?php echo '<input type="checkbox" name="emb_caption"'; if(isset($_POST['emb_caption'])) { echo ' checked="checked"'; } echo ' />Embed caption in image?'; echo '<br />'; //添加水印选项 echo '<input type="checkbox" name="emb_logo" '; if(isset($_POST['emb_logo'])) { echo 'checked="checked"'; } echo ' />Embed watermarked logo in image?'; ?> <input type="submit" value="Preview" name="submit" /><br /><br /> <input type="submit" value="Save" name="submit" /> </div> </form> <?php } ?>

这里面主要是添加水印选项，如果选中添加水印则将logo.png作为水印图片和原来的图片合并在一起。

在预览文件中添加了对应的逻辑，代码如下：

<?php $dir = 'D:Seriousphpdevtestimages'; //设置环境变量 putenv('GDFONTPATH='.'C:WindowsFonts'); $font = "arial"; if(isset($_GET['id']) && ctype_digit($_GET['id']) && file_exists($dir.'/'.$_GET['id'].'.jpg')) { $image = imagecreatefromjpeg($dir.'/'.$_GET['id'].'.jpg'); } else { die('invalid image specified'); } $effect = (isset($_GET['e'])) ? $_GET['e'] : -1; switch($effect) { case IMG_FILTER_NEGATE: imagefilter($image , IMG_FILTER_NEGATE); break; case IMG_FILTER_GRAYSCALE: imagefilter($image , IMG_FILTER_GRAYSCALE); break; case IMG_FILTER_EMBOSS: imagefilter($image , IMG_FILTER_EMBOSS); break; case IMG_FILTER_GAUSSIAN_BLUR: imagefilter($image , IMG_FILTER_GAUSSIAN_BLUR); break; } if(isset($_GET['capt'])) { //echo $_GET['capt']; imagettftext($image, 12, 0, 20, 20, 0, $font, $_GET['capt']); } if(isset($_GET['logo'])) { list($widht , $height) = getimagesize($dir.'/'.$_GET['id'].'.jpg'); list($wmk_width , $wmk_height) = getimagesize('images/logo.png'); $x = ($widht-$wmk_width) / 2; $y = ($height-$wmk_height) / 2; $wmk = imagecreatefrompng('images/logo.png'); imagecopymerge($image , $wmk , $x , $y , 0 , 0 , $wmk_width , $wmk_height , 20); imagedestroy($wmk); } header('Content-Type:image/jpeg'); imagejpeg($image , '' , 100); ?>

最后上传的水印图片效果如下：

注意主要的逻辑就是通过 imagecopymerge() 方法把两个图片合并在一起造成水印效果。来看看这个方法的方法原型和参数：

bool imagecopymerge ( resource $dst_im , resource $src_im , int $dst_x , int $dst_y , int$src_x , int $src_y , int $src_w , int $src_h , int $pct )

将 src_im 图像中坐标从 src_x，src_y 开始，宽度为 src_w，高度为 src_h 的一部分拷贝到 dst_im 图像中坐标为 dst_x 和 dst_y 的位置上。两图像将根据 pct 来决定合并程度，其值范围从 0 到 100。当 pct = 0 时，实际上什么也没做，当为 100 时对于调色板图像本函数和 imagecopy() 完全一样，它对真彩色图像实现了 alpha 透明。

以上内容是本文介绍PHP给图片添加水印 压缩 剪切的封装类的全部内容，希望大家对本文介绍感兴趣。