PadImage

PadImage.cs

public static System.Drawing.Image PadImage(System.Drawing.Image originalImage)
{
    int largestDimension = Math.Max(originalImage.Height, originalImage.Width);

    int h = originalImage.Size.Height;
    int w = originalImage.Size.Width;
    int final = 0;
    if (w >= h)
        final = h;
    else
        final = w;

    Size squareSize = new Size(final, final);
    Bitmap squareImage = new Bitmap(squareSize.Width, squareSize.Height);
    using (Graphics graphics = Graphics.FromImage(squareImage))
    {
        graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
        graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

        graphics.DrawImage(originalImage, (squareSize.Width / 2) - (originalImage.Width / 2), (squareSize.Height / 2) - (originalImage.Height / 2), originalImage.Width, originalImage.Height);
    }
    return squareImage;
}