How to reduce the size of an image in C# and .NET 3.5?

Question

I have a screen shot I take in my mobile app. The screen shot takes about 32 KB when saved as a png on a disk.

I am sending these to a central SQL Server and 32 KB

Answer 1

    private static Image ResizeImage(int newSize, Image originalImage)
    {
        if (originalImage.Width <= newSize)
            newSize = originalImage.Width;

        var newHeight = originalImage.Height * newSize / originalImage.Width;

        if (newHeight > newSize)
        {
            // Resize with height instead
            newSize = originalImage.Width * newSize / originalImage.Height;
            newHeight = newSize;
        }

        return originalImage.GetThumbnailImage(newSize, newHeight, null, IntPtr.Zero);
    }

This should work with your Bitmap object Type and resize the Height or Width, depending on which is appropriate for your image dimensions. It will also maintain scale.

EDIT:

You could create a new Bitmap object and resize your original image into that Bitmap object.

Bitmap b = new Bitmap(newWidth, newHeight);
Graphics g = Graphics.FromImage((Image)b);
g.InterpolationMode = InterpolationMode.HighQualityBicubic;

g.DrawImage(imgToResize, 0, 0, newWidth, newHeight);
g.Dispose();

return (Image)b;

I don't have the Compact Framework installed, but it seems that this should work for you.