Vidka.Core.ExternalOps.ThumbnailExtraction.StitchIntoOneBmp C# (CSharp) Method

        private void StitchIntoOneBmp(string TmpFolder, string outFilename)
        {
            var imgsFiles = Directory.GetFiles(TmpFolder)
                .Where(fff => fff.Contains("out") && fff.Contains(".jpg"))
                .ToArray();
            if (imgsFiles.Length == 0) {
                ErrorMessage2 = "No thumbnails found in tmp directory";
                return;
            }

            var nCol = (int)Math.Ceiling(Math.Sqrt(imgsFiles.Length));
            var nRow = (int)Math.Ceiling((double)imgsFiles.Length / nCol);

            #if ONE_LINE_TEST
            // tmp 1 line test
            nCol = imgsFiles.Length;
            nRow = 1;
            #endif

            Bitmap allThumbs = new Bitmap(nCol*ThumbW, nRow*ThumbH);
            Graphics ggg = Graphics.FromImage(allThumbs);
            int i = 1;
            for (int r = 0; r < nRow; r++) {
                for (int c = 0; c < nCol; c++) {
                    Bitmap bmp = (Bitmap)Image.FromFile(String.Format("{0}/out{1}.jpg", TmpFolder, i));
                    ggg.DrawImage(bmp, ThumbW * c, ThumbH * r);
                    bmp.Dispose();
                    i++;
                    if (i > imgsFiles.Length)
                        break;
                }
                if (i > imgsFiles.Length)
                    break;
            }
            ggg.Flush();

            // save all to one jpg file
            if (File.Exists(outFilename)) {
                if (PleaseUnlockThisFile != null)
                    PleaseUnlockThisFile(outFilename);
                File.Delete(outFilename);
            }
            allThumbs.Save(outFilename, ImageFormat.Jpeg);
            allThumbs.Dispose();

            // delete all tmp images
            foreach (var fff in imgsFiles)
                File.Delete(fff);
        }