2

可能重复：
使用 php gd2 将图像从一种格式保存到另一种格式

我正在将任何图像格式转换为 JPEG 或 JPG。将图像转换为 jpg 的代码是 

function converttojpg($originalimg)
{
$filetype = @end(explode(".", $originalimg));
echo $originalimg . " asdasdfs";
if (strtolower($filetype) == 'jpg' or strtolower($filetype) == 'jpeg') 
    {
    $srcImg = imagecreatefromjpeg($originalimg);
    imagejpeg($srcImg,$originalimg,100);
    imagedestroy($srcImg);
    } 
if (strtolower($filetype) == 'png') 
    {
    $srcImg = imagecreatefrompng($originalimg);
    imagejpeg($srcImg,$originalimg,100);
    imagedestroy($srcImg);
    } 
if (strtolower($filetype) == 'gif') 
    {
    echo "executed";
    $srcImg = imagecreatefromgif($originalimg);
    imagejpeg($srcImg,$originalimg,100);
    imagedestroy($srcImg);
    }
}

之后我调整转换后的图像的大小，其代码是 

function resizeImage($originalImage,$toWidth,$toHeight)
{
// Get the original geometry and calculate scales
list($width, $height) = getimagesize($originalImage);
$xscale=$width/$toWidth;
$yscale=$height/$toHeight;

// Recalculate new size with default ratio
if ($yscale>$xscale)
    {
    $new_width = round($width * (1/$yscale));
    $new_height = round($height * (1/$yscale));
    }
else 
    {
    $new_width = round($width * (1/$xscale));
    $new_height = round($height * (1/$xscale));
    }
// Resize the original image
$imageResized = imagecreatetruecolor($new_width, $new_height);
$imageTmp     = imagecreatefromjpeg ($originalImage);
imagecopyresampled($imageResized, $imageTmp, 0, 0, 0, 0, $new_width, $new_height, $width, $height           );
return $imageResized;
}

并在每张图片上报告错误和警告 

    Warning: imagecreatefromjpeg() [function.imagecreatefromjpeg]: gd-jpeg, libjpeg: recoverable error: Corrupt JPEG data: 9 extraneous bytes before marker 0xd9 in E:\xampp\htdocs\photo\functions.php on line 33

Warning: imagecreatefromjpeg() [function.imagecreatefromjpeg]: 'userphotos/corrupted_image_1.jpg' is not a valid JPEG file in E:\xampp\htdocs\photo\functions.php on line 33

Warning: imagejpeg() expects parameter 1 to be resource, boolean given in E:\xampp\htdocs\photo\functions.php on line 34

Warning: imagedestroy() expects parameter 1 to be resource, boolean given in E:\xampp\htdocs\photo\functions.php on line 35

Warning: imagecreatefromjpeg() [function.imagecreatefromjpeg]: gd-jpeg, libjpeg: recoverable error: Corrupt JPEG data: 9 extraneous bytes before marker 0xd9 in E:\xampp\htdocs\photo\functions.php on line 22

Warning: imagecreatefromjpeg() [function.imagecreatefromjpeg]: 'userphotos/53.jpg' is not a valid JPEG file in E:\xampp\htdocs\photo\functions.php on line 22

Warning: imagecopyresampled() expects parameter 2 to be resource, boolean given in E:\xampp\htdocs\photo\functions.php on line 23
userphotos/MG_diesel-04.gif_thumb.png asdasdfsuserphotos/Porsche_911_996_Carrera_4S.jpg asdasdfs


请帮我解决这个问题。我必须完成它。

4

2 回答 2

0

不要使用扩展名来确定文件类型。要检查给定文件是否是图像并且格式允许 GD 操作它，请使用getimagesize

于 2012-03-18T18:40:25.870 回答
-1 
<?php
    $image = @imagecreatefromstring(file_get_contents($file_path));
        if ($image === false) {
            throw new Exception (sprintf('invalid image or file not found, file=%s', $file_path));
        }
?>

imagecreatefromstring 检测图像类型并创建图像资源，否则抛出异常。

于 2012-03-18T18:44:37.867 回答