stacker.cs

// Make a variable of: List<Image>
// I'm not going to give any support other than saying that you need to run this in a form app in c#
// It assumes a image size of 256 x 256, change the values at will.

                    var numperrow = 4;
                    var w = 256 * numperrow;
                    int h = int.Parse(Math.Ceiling(double.Parse(imgs.Count.ToString()) / numperrow).ToString()) * 256;
                    if (imgs.Count * 256 < 256 * numperrow)
                    {
                        w = imgs.Count * 256;
                    }
                    var num = 1;

                    var cur_w = 0;
                    var cur_h = 0;

                    Bitmap bmp = new Bitmap(w, h);
                    using (Graphics g = Graphics.FromImage(bmp))
                    {

                        foreach (var i in imgs)
                        {
                            g.DrawImage(i, new PointF(cur_w, cur_h));
                            if (num % numperrow == 0)
                            {
                                cur_w = 0;
                                cur_h += 256;
                                num += 1;
                            }
                            else
                            {
                                cur_w += 256;
                                num += 1;
                            }
                        }
                    }

                    bmp.Save(Directory.GetCurrentDirectory() + "output.png");