文件上传仅适用于某些图像(class.upload.php)

我尝试了使用PHP上传图像的本机方法，但是我的朋友向我建议使用class.upload.php库，该库的结果仍然与以前相同.我只能上传某些图像而没有它们的小图标，这意味着浏览器无法找到该图像，但是奇怪的是，当我将无效"图像下载到计算机上时，它们就可以了.大约有50％的图像实际上可以工作，但其余图像仅显示应具有的适当大小，但没有图像.这是我的代码(我的html表单具有名为filename的文件输入类型:

I've tried the native way of uploading images with PHP, but my friend suggested me to the class.upload.php library, which still had the same results as before. I can only upload certain images without them having that little icon that means that the browser can't find the image, but what's weird is that when I download the "invalid" images to my computer, they're fine. About 50% of images actually do work, but the rest just show the appropriate size that they should have but no image. Here is my code (my html form has a file input type called filename:

$handle = new upload($_FILES['filename']);

if ($handle->uploaded)   
{
   if ($file_src_size < 20000)
   {
        $handle->file_new_name_body = "test";  
        $handle->image_convert = 'jpg';
        $handle->process('/');  

        echo "<img src = \"test.jpg\" />";
    }
    else echo "Files must be 20 kb or under";
}
else echo "Upload failed, please try again";