在PHP中将BMP转换为JPG [英] Converting BMP to JPG in PHP

问题描述

在我正在开发的网站中，我需要能够通过imagejpeg（）传递我的所有图像，所以我决定（因为我的网站只接受JPG，BMP + PNG上传）来简单地将BMP和PNG转换为JPG第一个。

In a site I'm developing I need to be able to pass all my images through imagejpeg(), so I decided (as my site only accepts JPG, BMP + PNG uploads) to simply convert BMPs and PNGs to a JPG first.

现在转换BMP我使用了这里找到的脚本：
http://forums.codewalkers.com/php-coding-7/how-to-convert-bmp- to-jpg-879135.html

Now to convert the BMP I used the script found here: http://forums.codewalkers.com/php-coding-7/how-to-convert-bmp-to-jpg-879135.html

当我通过普通BMP时，脚本运行正常。

The script works fine when I pass a normal BMP through it.

现在，我有一个PNG，我通过imagecreatefrompng（）进行转换时遇到了问题，过了一段时间我意识到它有mime-type image / x-ms-bmp ....

Now, I had a PNG which I had problems converting via imagecreatefrompng(), and after a while I realised it had the mime-type image/x-ms-bmp....

我尝试通过BMP脚本传递图像，但是我收到以下错误：

I tried passing the image through the BMP script but I get the following error:

警告：imagecreatefromgd（ ）[function.imagecreatefromgd]：'C：\ Users \Tom \ AppData \ Local \ Temp \ GD50C1.tmp'不是有效的GD第10行的C：\ xampp \ htdocs \ test\cropimage \ FCreateImageFromBMP.php文件

Warning: imagecreatefromgd() [function.imagecreatefromgd]: 'C:\Users\Tom\AppData\Local\Temp\GD50C1.tmp' is not a valid GD file in C:\xampp\htdocs\test\cropimage\FCreateImageFromBMP.php on line 10

如果有人有来之前，请帮忙。
如果您需要查看任何代码，请告诉我们。

If anyone has come accross this before, please help. If you need to see any code, just let me know.

提前致谢，Tom。

编辑：
可能有用的是，发生错误的行（从上面的链接开始）si这一行：

Might be useful to mention, the line which the error occurs on (as from the link above) si this one:

$tmp_name = tempnam("/tmp", "GD");

推荐答案

如果有一些先决条件，您链接的代码将会失效失败：

The code you linked to bails out if a few preconditions fail:

if(!($src_f = fopen($src, "rb"))) { 
...
if(!($dest_f = fopen($dest, "wb"))) { 
...
if($type != 0x4D42) { // signature "BM" 

因此假设源文件和tmp文件是可读/可写的，它看起来就像你的文件给它（它以.png发送但是给出BMP mime类型）实际上也不是BMP文件，因为文件内容不以BM标识符开头。如果您附加文件，也许有人可以确定它到底是什么。

So assuming that the source and tmp files are read/writable, it looks like the file you are giving it (which is sent as a .png but gives a BMP mime type) is in fact not a BMP file either, because the file contents don't start with the "BM" identifier. If you attach the file, perhaps somebody could identify what it really is.

我用来解决这个问题的另一个解决方案是使用ImageMagick的convert命令来转换大多数文件类型，无论它们是什么，都是所需的格式：

Another solution I've used to this problem is to use ImageMagick's convert command to convert most file types, whatever they may be, to the desired format:

// convert uses the file extension to determine the output format, so
// change .jpg to whatever you'd like
$tmp_name = tempnam("/tmp", "convert") . '.jpg';
exec('c:\path\to\imagemagick\convert ' . $inputFile . ' ' . $tmp_name);

您可以在此处获取适用于Windows和其他平台的ImageMagick：
http://www.imagemagick.org/script/binary-releases.php

You can get ImageMagick for Windows and other platforms here: http://www.imagemagick.org/script/binary-releases.php

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