I am using ASP.NET MVC and I've an action that uploads the file. The file is being uploaded properly. But I want width and height of the image. I think I need to convert the HttpPostedFileBase
to Image
first and then proceed. How do I do that?
And please let me know if there is another better way to get the width and height of the image.
I use Image.FromStream
to as follows:
Image.FromStream(httpPostedFileBase.InputStream, true, true)
Note that the returned Image
is IDisposable
.
You'll need a reference to System.Drawing.dll
for this to work, and Image
is in the System.Drawing
namespace.
I'm not sure what you're trying to do, but if you happen to be making thumbnails or something similar, you may be interested in doing something like...
try {
var bitmap = new Bitmap(newWidth,newHeight);
using (Graphics g = Graphics.FromImage(bitmap)) {
g.SmoothingMode = SmoothingMode.HighQuality;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.CompositingQuality = CompositingQuality.HighQuality;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(oldImage,
new Rectangle(0,0,newWidth,newHeight),
clipRectangle, GraphicsUnit.Pixel);
}//done with drawing on "g"
return bitmap;//transfer IDisposable ownership
} catch { //error before IDisposable ownership transfer
if (bitmap != null) bitmap.Dispose();
throw;
}
where clipRectangle
is the rectangle of the original image you wish to scale into the new bitmap (you'll need to manually deal with aspect ratio). The catch-block is typical IDisposable
usage inside a constructor; you maintain ownership of the new IDisposable
object until it is returned (you may want to doc that with code-comments).
Unfortunately, the default "save as jpeg" encoder doesn't expose any quality controls, and chooses a terribly low default quality.
You can manually select the encoder as well, however, and then you can pass arbitrary parameters:
ImageCodecInfo jpgInfo = ImageCodecInfo.GetImageEncoders()
.Where(codecInfo => codecInfo.MimeType == "image/jpeg").First();
using (EncoderParameters encParams = new EncoderParameters(1))
{
encParams.Param[0] = new EncoderParameter(Encoder.Quality, (long)quality);
//quality should be in the range [0..100]
image.Save(outputStream, jpgInfo, encParams);
}