我正在阅读JPEG的Exif信息以旋转图像。 JPEG在ASP.NET中上传,我读取上传流,旋转并保存。它在我的开发机器(Windows 10,IIS 10)上完美运行,但是当我尝试使用服务器(Windows Server 2012 R2,IIS 8.5)时,它不起作用,它不会加载任何Exif信息。
这是代码:
void SavePhoto()
{
// PHOTO is the Html
HttpPostedFile photo = Request.Files["ProfilePhoto_File"];
using (var image = Image.FromStream(photo.InputStream, true, true))
{
SaveConvertingFormat(image, "output_path.jpg");
}
}
public static void SaveConvertingFormat(Image image, string outputPath)
{
int imageWidth = image.Width;
int imageHeight = image.Height;
using (var result = new Bitmap(imageWidth, imageHeight))
{
using (var g = Graphics.FromImage(result))
{
g.DrawImage(image, 0, 0, imageWidth, imageHeight);
}
var rotation = GetExifRotate(image, outputPath);
// IN THE SERVER, rotation IS ALWAYS RotateNoneFlipNone
if (rotation != RotateFlipType.RotateNoneFlipNone)
result.RotateFlip(rotation);
SaveJpeg(result, outputPath, 85);
}
}
private static void SaveJpeg(this Image img, string filename, int quality)
{
EncoderParameter qualityParam = new EncoderParameter(Encoder.Quality, (long)quality);
ImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
EncoderParameters encoderParams = new EncoderParameters(1);
encoderParams.Param[0] = qualityParam;
img.Save(filename, jpegCodec, encoderParams);
}
public static RotateFlipType GetExifRotate(Image img, string outputPath)
{
// Source: https://stackoverflow.com/a/48347653/72350
// ERROR:
// IN THE PRODUCTION SERVER, PropertyIdList IS EMPTY!
const int ExifOrientationId = 0x112;
if (!img.PropertyIdList.Contains(ExifOrientationId))
return RotateFlipType.RotateNoneFlipNone;
var prop = img.GetPropertyItem(ExifOrientationId);
int val = BitConverter.ToUInt16(prop.Value, 0);
var rot = RotateFlipType.RotateNoneFlipNone;
if (val == 3 || val == 4)
rot = RotateFlipType.Rotate180FlipNone;
else if (val == 5 || val == 6)
rot = RotateFlipType.Rotate90FlipNone;
else if (val == 7 || val == 8)
rot = RotateFlipType.Rotate270FlipNone;
if (val == 2 || val == 4 || val == 5 || val == 7)
rot |= RotateFlipType.RotateNoneFlipX;
return rot;
}
再次,上面的代码:
有什么建议?
无需剥离EXIF数据。 AutoOrient()自动将EXIF方向设置为TopLeft。
您还需要使用using子句,因为MagickImage实现了IDisposable。
using (var img = new MagickImage(inputStream))
{
img.AutoOrient(); // Fix orientation
img.Write(outputPath);
}
以防有人有同样的问题。我在生产中使用WFP和GDI阅读方向时遇到了问题。
使用WPF时,错误是:
System.Runtime.InteropServices.COMException (0x88982F8A): The component registration is invalid.
(Exception from HRESULT: 0x88982F8A)
at System.Windows.Media.Imaging.BitmapMetadata.GetQuery(String query)
解:
唯一有用的是使用:https://github.com/dlemstra/Magick.NET
代码很简单:
var img = new MagickImage(inputStream);
img.AutoOrient(); // Fix orientation
img.Strip(); // remove all EXIF information
img.Write(outputPath);
它还帮我删除了10行。