Make a square image

gistfile1.cs

private Image MakeSquareImage(Image source, int targetLength)
{
    var sourceBitmap = new Bitmap(source);

    var sourceLength = Math.Min(source.Size.Height, source.Size.Width);

    var cropRect = new Rectangle((source.Size.Width - sourceLength)/2, (source.Size.Height - sourceLength)/2, sourceLength, sourceLength);

    var squaredSource = sourceBitmap.Clone(cropRect, sourceBitmap.PixelFormat);
    var result = new Bitmap(squaredSource, new Size(targetLength, targetLength));
    return result;
}