这篇是关于修改图片的效果，主要还是用到php中的GD库中的函数，没想到php还有这凶残能力，出乎我的预料。
先看代码upload_image.php，主要是一个上传控件，用来选择图片
<html> <head> <title></title> <style type="text/css"></style> </head> <body> <form action="check_image.php" method="post" enctype="multipart/form-data"> <table> <tr> <td>Your username</td> <td><input type="text" name="username" /></td> </tr> <tr> <td>Upload image*</td> <td><input type="file" name="uploadfile"/></td> </tr> <tr> <td colspan="2"> <small><em> * Acceptable image formats include: GIF, JPG/JPEG and PNG.</em></small> </td> </tr> <tr> <td>Image Caption</td> <td><input type="text" name="caption"/></td> </tr> <tr> <td colspan="2" style="text-align:center;"> <input type="submit" name="submit" value="Upload" /> </td> </tr> </table> </form> </body> </html>
然后是上传和处理图片的逻辑check_image.php
<?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 $dir = 'D:Seriousphpdev estimages'; //upload_image.php页面传递过来的参数，如果是上传图片 if($_POST['submit'] == 'Upload') { if($_FILES['uploadfile']['error'] != UPLOAD_ERR_OK) { switch($_FILES['uploadfiel']['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; } 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'];?>.jpg" alt="" /> </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> <!--<img src="images/<?php echo $imagename;?>" alt="" style="float:left;" />--> </body> </html> <?php if($_POST['submit'] == 'Upload') { $imagename = 'images/'.$image_id.'.jpg'; } else { $imagename = 'image_effect.php?id='.$image_id.'&e='.$_POST['effect']; } ?> <img src="<?php echo $imagename;?>" style="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'];?>" method="post"> <div> <input type="hidden" name="id" value="<?php echo $image_id;?>"/> <select name="effect" id=""> <option value="-1">None</option> <?php echo '<option value="'.IMG_FILTER_GRAYSCALE.'" '; if(isset($_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 /> <input type="submit" value="Preview" name="submit" /><br /> <input type="submit" value="Save" name="submit" /> </div> </form> <?php } ?>
最后是一个预览效果的页面image_effect.php
<?php $dir = 'D:Seriousphpdev estimages'; if(isset($_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; } header('Content-Type:image/jpeg'); imagejpeg($image , '' , 100); ?>
第二个image_check.php有点乱，在这个页面中有上传图片，处理图片，还有预览图片的部分逻辑，注意下面这段
<?php if($_POST['submit'] == 'Upload') { $imagename = 'images/'.$image_id.'.jpg'; } else { $imagename = 'image_effect.php?id='.$image_id.'&e='.$_POST['effect']; } ?> <img src="<?php echo $imagename;?>" style="float:left;" alt="" />
如果是上传直接访问图片，如果是预览则从image_effect.php中读取图片，这里是从内存中读取图片并根据选择的处理效果来展示图片。如下
switch($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; }
当使用imagefilter方法处理图片之后会把图片输出到页面，这里要注意imagejpeg方法的第二个参数是空字符串，这样它就不会写入到硬盘中了，如果第二个参数设置了会覆盖原有的图片，这样可以让用户在保存图片之前随意的预览效果，如下：
header('Content-Type:image/jpeg'); imagejpeg($image , '' , 100);
在check_image.php中有调用到类似的方法，但是这里指定了第二个参数，就是用来保存图片的：
imagejpeg($image , $dir.'/'.$_POST['id'].'.jpg' , 100);
注意这里哦我们只写了三种处理效果，这个只是所有枚举中的一部分，我们来看所有的处理方式：
IMG_FILTER_NEGATE：将图像中所有颜色反转。
IMG_FILTER_GRAYSCALE：将图像转换为灰度的。
IMG_FILTER_BRIGHTNESS：改变图像的亮度。用 arg1 设定亮度级别。
IMG_FILTER_CONTRAST：改变图像的对比度。用 arg1 设定对比度级别。
IMG_FILTER_COLORIZE：与 IMG_FILTER_GRAYSCALE 类似，不过可以指定颜色。用 arg1，arg2 和 arg3 分别指定 red，blue 和 green。每种颜色范围是 0 到 255。
IMG_FILTER_EDGEDETECT：用边缘检测来突出图像的边缘。
IMG_FILTER_EMBOSS：使图像浮雕化。
IMG_FILTER_GAUSSIAN_BLUR：用高斯算法模糊图像。
IMG_FILTER_SELECTIVE_BLUR：模糊图像。
IMG_FILTER_MEAN_REMOVAL：用平均移除法来达到轮廓效果。
IMG_FILTER_SMOOTH：使图像更柔滑。用 arg1 设定柔滑级别。
是不是很惊艳，php很强大的。