VintaSoft Twain .NET SDK Discussions

Hi,

I am following your example for scanning the top part of a page. I am testing on 2 scanners. One is a Canon and the other is a Fujitsu Fi-7160. It works fine on the Canon, but the Fujitsu scans the entire page every time. Here is the code that I believe is meaningful:

                    device.UnitOfMeasure = UnitOfMeasure.Inches;
                    device.ImageLayout.Reset();
                    device.ImageLayout.Set(0f, 0f, 8.5f, 5f);
                    device.Acquire();

Any thoughts on why it would work on a Canon, but not the Fujitsu? Or anything I could do to resolve the issue?

Here is the full code:

    class Program
    {
        /// <summary>
        /// The main program.
        /// </summary>
        /// <param name="args"></param>
        static void Main(string[] args)
        {
            Console.WriteLine("Starting...");
            TwainGlobalSettings.Register("S******", "****@******.com", "****-**-**", "*****");
            try
            {
                Console.WriteLine("Select a scanner by entering its number.  Press x to quit.");
                DeviceManager deviceManager = new DeviceManager();

                deviceManager.Open();
                Scan(deviceManager);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            finally
            {
                Console.ReadLine();
            }
        }

        /// <summary>
        /// Scans an image.
        /// </summary>
        /// <param name="deviceManager"></param>
        private static void Scan(DeviceManager deviceManager)
        {
            Device device = null;

            try
            {
                ListDevices(deviceManager);
                var selected = GetSelectedScanner(deviceManager);
                if (selected >= 0)
                {
                    device = deviceManager.Devices[selected];
                    device.Open();
                    device.ShowUI = false;

                    SubscribeToDeviceEvents(device);

                    device.UnitOfMeasure = UnitOfMeasure.Inches;
                    device.ImageLayout.Reset();
                    device.ImageLayout.Set(0f, 0f, 8.5f, 5f);
                    device.Acquire();
                }
            }
            catch
            {
                // if device is found
                if (device != null)
                {
                    // if device is opened
                    if (device.State >= DeviceState.Opened)
                    {
                        // close the device
                        device.Close();
                    }

                    UnsubscribeFromDeviceEvents(device);
                }

                throw;
            }
        }

        /// <summary>
        /// Lists the devices.
        /// </summary>
        /// <param name="deviceManager"></param>
        private static void ListDevices(DeviceManager deviceManager)
        {
            var devices = deviceManager.Devices;
            for (int i = 0; i < devices.Count; i++)
            {
                if (!devices[i].Info.IsWIA)
                {
                    Console.WriteLine($"[{(i + 1).ToString("d2")}] {devices[i].Info.ProductName}");
                }
            }
        }

        /// <summary>
        /// Allows the user to select a scanner.
        /// </summary>
        /// <param name="deviceManager"></param>
        /// <returns>
        /// If a scanner is selected, returns the index of the selected scanner and -1 otherwise.
        /// </returns>
        private static int GetSelectedScanner(DeviceManager deviceManager)
        {
            do
            {
                Console.WriteLine("");
                Console.Write("Enter the number of the scanner to select it: ");
                var enteredString = Console.ReadLine();
                if (int.TryParse(enteredString, out int scannerNumber))
                {
                    scannerNumber--;
                    if ((scannerNumber >= deviceManager.Devices.Count)
                        || (scannerNumber < 0))
                    {
                        Console.WriteLine("Invalid number.  Try again.");
                    }
                    else
                    {
                        return scannerNumber;
                    }
                }
                else if (string.Compare("x", enteredString, true) == 0)
                {
                    return -1;
                }
                else
                {
                    Console.WriteLine($"{enteredString} is not a number.");
                }
            } while (true);

            deviceManager.Close();
        }

        /// <summary>
        /// Image is acquired.
        /// </summary>
        private static void device_ImageAcquired(object sender, ImageAcquiredEventArgs e)
        {
            var path = System.IO.Path.Combine(System.IO.Directory.GetCurrentDirectory(), $"image{DateTime.Now.ToString("yyyy-MM-dd HH-mm-ss")}.bmp");
            e.Image.Save(path);

            Process.Start(path);

            // dispose the acquired image
            e.Image.Dispose();
        }

        /// <summary>
        /// Scan is completed.
        /// </summary>
        private static void device_ScanCompleted(object sender, System.EventArgs e)
        {
            Console.WriteLine("Scan is competed.");
            Console.WriteLine("Press enter to exit");
            Console.Read();
        }

        /// <summary>
        /// Scan is canceled.
        /// </summary>
        private static void device_ScanCanceled(object sender, System.EventArgs e)
        {
            Console.WriteLine("Scan is canceled.");
            Console.WriteLine("Press enter to exit");
            Console.Read();
        }

        /// <summary>
        /// Scan is failed.
        /// </summary>
        private static void device_ScanFailed(object sender, ScanFailedEventArgs e)
        {
            Console.WriteLine(string.Format("Scan is failed: {0}", e.ErrorString));
            Console.WriteLine("Press enter to exit");
            Console.Read();
        }

        /// <summary>
        /// Called when the scan is finished.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private static void device_ScanFinished(object sender, System.EventArgs e)
        {
            Device device = (Device)sender;

            // unsubscribe from device events
            UnsubscribeFromDeviceEvents(device);

            // if device is not closed
            if (device.State != DeviceState.Closed)
            {
                // close the device
                device.Close();
            }
        }

        /// <summary>
        /// Subscribes to the device events.
        /// </summary>
        /// <param name="device"></param>
        private static void SubscribeToDeviceEvents(Device device)
        {
            device.ImageAcquired += new System.EventHandler<ImageAcquiredEventArgs>(device_ImageAcquired);
            device.ScanCompleted += new System.EventHandler(device_ScanCompleted);
            device.ScanCanceled += new System.EventHandler(device_ScanCanceled);
            device.ScanFailed += new System.EventHandler<ScanFailedEventArgs>(device_ScanFailed);
            device.ScanFinished += new System.EventHandler(device_ScanFinished);
        }

        /// <summary>
        /// Unsubscribes to the device events.
        /// </summary>
        /// <param name="device"></param>
        private static void UnsubscribeFromDeviceEvents(Device device)
        {
            device.ImageAcquired -= new System.EventHandler<ImageAcquiredEventArgs>(device_ImageAcquired);
            device.ScanCompleted -= new System.EventHandler(device_ScanCompleted);
            device.ScanCanceled -= new System.EventHandler(device_ScanCanceled);
            device.ScanFailed -= new System.EventHandler<ScanFailedEventArgs>(device_ScanFailed);
            device.ScanFinished -= new System.EventHandler(device_ScanFinished);
        }
    }

Thank you,
Steve

Thanks so much for the quick response. Set the Device.PageSize and it is working as expected for both scanners.