Resizing an Image without losing any quality

Question

How can I resize an image, with the image quality unaffected?

Answer 1

As rcar says, you can't without losing some quality, the best you can do in c# is:

Bitmap newImage = new Bitmap(newWidth, newHeight);
using (Graphics gr = Graphics.FromImage(newImage))
{
    gr.SmoothingMode = SmoothingMode.HighQuality;
    gr.InterpolationMode = InterpolationMode.HighQualityBicubic;
    gr.PixelOffsetMode = PixelOffsetMode.HighQuality;
    gr.DrawImage(srcImage, new Rectangle(0, 0, newWidth, newHeight));
}