public static void RemoveBackground(App app)
        {
            if (app.Filename == null) return;
            if (app.Image == null) return;

            var img = app.Image;
            if (img == null) return;

            app.Task = "Remove background color";

            var helper = new RemoveBackgroundColorHelper();
            helper.Step1_SetImage(img);
            helper.Step2_SetDetectByFirstRow();
            helper.Step3_RemoveBackground();

            app.ErrorMessage = null;
            app.UI(UI.ErrorMessage);
            try {
                img.Save(app.Filename, "png");
            } catch (Exception ex) {
                app.ErrorMessage = ex.Message;
                app.UI(UI.ErrorMessage);
                Console.WriteLine(ex.ToString());
            }

            app.UI(UI.CompletedTask);

            AnalyzeAction.Analyze(app);
        }
        public static void RemoveBackground(App app)
        {
            if (app.Filename == null)
            {
                return;
            }
            if (app.Image == null)
            {
                return;
            }

            var img = app.Image;

            if (img == null)
            {
                return;
            }

            app.Task = "Remove background color";

            var helper = new RemoveBackgroundColorHelper();

            helper.Step1_SetImage(img);
            helper.Step2_SetDetectByFirstRow();
            helper.Step3_RemoveBackground();

            app.ErrorMessage = null;
            app.UI(UI.ErrorMessage);
            try {
                img.Save(app.Filename, "png");
            } catch (Exception ex) {
                app.ErrorMessage = ex.Message;
                app.UI(UI.ErrorMessage);
                Console.WriteLine(ex.ToString());
            }

            app.UI(UI.CompletedTask);

            AnalyzeAction.Analyze(app);
        }