php网站如何修改图片

发布时间：2020-09-17 10:49:34 作者：小新
来源：亿速云阅读：146

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！

php网站如何修改图片

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