小编给大家分享一下php网站如何修改图片，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！
主要还是用到php中的GD库中的函数
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 $dir = 'D:\Serious\phpdev\test\images'; //upload_image.php页面传递过来的参数，如果是上传图片 if($_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> <h2>Your image has been saved!</h2> <img src="images/<?php echo $_POST['id'];?>.jpg" alt="" /> </body> </html> <?php } else { ?> <html> <head> <title>Here is your pic!</title> </head> <body> <h2>So how does it feel to be famous?</h2> <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
$dir = 'D:\Serious\phpdev\test\images';
if(isset($_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($image , '' , 100);
?>当使用imagefilter方法处理图片之后会把图片输出到页面，这里要注意imagejpeg方法的第二个参数是空字符串，这样它就不会写入到硬盘中了，如果第二个参数设置了会覆盖原有的图片，这样可以让用户在保存图片之前随意的预览效果，如下：
header('Content-Type:image/jpeg');
imagejpeg($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);
php中处理图片的方法：
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。
以上是php网站如何修改图片的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注亿速云行业资讯频道！
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