CODEWITHSUNDEEP
c#image-resizing
Lasse Edsvik
Lasse Edsvik

Reputation: 9298

Grey and unsharp images when resizing using GDI+

I'm using asp.net mvc 3 to stream resized images. But the output of the image is greyish and blury eventhough I've set smoothingmode and interpolationmode to highbiqubic.

public ActionResult ImageTEST(int fileID, int width, int height)
{
    var file = _fileRep.GetFile(fileID);
    byte[] newFile;

    float ratioX = (float)width / (float)file.Width;
    float ratioY = (float)height / (float)file.Height;
    float ratio = Math.Min(ratioX, ratioY);

    int newWidth = (int)(file.Width * ratio);
    int newHeight = (int)(file.Height * ratio);

    using (var resizedImage = new Bitmap(newWidth, newHeight))
    {
        using (var source = new Bitmap(new MemoryStream(file.FileContent)))
        {
            using (var g = Graphics.FromImage(resizedImage))
            {
                g.SmoothingMode = SmoothingMode.HighQuality;
                g.InterpolationMode = InterpolationMode.HighQualityBicubic;
                g.DrawImage(source, 0, 0, newWidth, newHeight);
            }
        }

        using (var ms = new MemoryStream())
        {
            resizedImage.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);

            newFile = ms.ToArray();
        }
    }

    return new FileContentResult(newFile, "image/jpeg");
}

Result:

enter image description here

The right one is the exakt same picture but resized in photoshop.

How can I tune this to make quality much better?

Upvotes: 0

Views: 112

Answers (1)

Naruil
Naruil

Reputation: 2310

First, try to save in a higher quality.

EncoderParameters ep = new EncoderParameters(); 
ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (long)100); 
foo.Save(filename, ici, ep);

If that is not satisfiable, you may need to use other libraries such as Emgu cv.

The grey problem may because that the color space (AdobeRGB or sRGB) of original image and the one you saved are not the same.

Upvotes: 1

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