PHP imagecreatefromjpeg有效，为什么png / bmp / gif没有工作？

本文介绍了PHP imagecreatefromjpeg有效，为什么png / bmp / gif没有工作？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我想上传和调整不同扩展名的图片。 php从原始图片的中心裁剪出最大可能的正方形，然后将其保存为360 * 360像素。

I want to upload and resize pictures with different extensions. The php crops the biggest possible square from the center of the original pic, then saves it in 360*360 pixels.

代码适用于jpeg文件，但是使用gif，bmp和png我得到一个33字节大小的损坏文件。

The code works fine with jpeg files, but with gif, bmp and png I get a corrupted file with 33 Byte size.

以下是大部分代码：

$file_temp = $_FILES["pic"]["tmp_name"]; list ($width, $height, $type) = getimagesize ($file_temp); $picture_name = "... a name.ext ..."; $upload = "... some dir/$picture_name"; if (move_uploaded_file($file_temp, "$upload")) { //switches content-type and calls the imagecreatefrom... function if ($type == 1) { header ('Content-Type: image/gif'); $image = imagecreatefromgif($upload); } elseif ($type == 2) { header ('Content-Type: image/jpeg'); $image = imagecreatefromjpeg($upload); } elseif ($type == 3) { header ('Content-Type: image/png'); $image = imagecreatefrompng($upload); } else { header ('Content-Type: image/x-ms-bmp'); $image = imagecreatefromwbmp($upload); } $image_p = imagecreatetruecolor(360, 360); //this code below should preserve transparency but I couldn't try it out for now... if($type==1 or $type==3) { imagecolortransparent($image_p, imagecolorallocatealpha($image_p, 0, 0, 0, 127)); imagealphablending($image_p, true); imagesavealpha($image_p, true); } //this part is for cropping $x=0; $y=0; if ($width > $height) { $x= ($width - $height)/2; $width = $height; } else { $y = ($height - $width)/2; $height = $width; } imagecopyresampled ($image_p, $image, 0, 0, $x, $y, 360, 360, $width, $height); if ($type == 1) imagegif ($image_p, $upload, 80); elseif ($type == 2) imagejpeg ($image_p, $upload, 80); elseif ($type == 3) imagepng ($image_p, $upload, 80); else imagewbmp ($image_p, $upload, 80); }

因此，只有正确处理jpeg文件，gif，png和bmp文件都没有T。我没有想法... 提前致谢！

So, only jpeg files are processed correctly, gif, png and bmp files aren't. I'm out of ideas... Thanks in advance!

推荐答案

您的PHP可能不是编译时支持这些格式。运行phpinfo（）并检查输出，如下所示：

Your PHP may not be compiled with support for those formats. Run a phpinfo() and inspect the output for something like this:

GD Support => enabled GD Version => bundled (2.0.34 compatible) GIF Read Support => enabled GIF Create Support => enabled PNG Support => enabled libPNG Version => 1.2.10