need help on a scanner code

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C#

using System;
using System.Collections.Generic;
using System.IO;
using System.Drawing;
 
namespace WIATest
{
class WIAScanner
{
const string wiaFormatBMP = "{B96B3CAB-0728-11D3-9D7B-0000F81EF32E}";
 
class WIA_DPS_DOCUMENT_HANDLING_SELECT
{
public const uint FEEDER = 0x00000001;
public const uint FLATBED = 0x00000002;
}
 
class WIA_DPS_DOCUMENT_HANDLING_STATUS
{
public const uint FEED_READY = 0x00000001;
}
 
class WIA_PROPERTIES
{
public const uint WIA_RESERVED_FOR_NEW_PROPS = 1024;
public const uint WIA_DIP_FIRST = 2;
public const uint WIA_DPA_FIRST = WIA_DIP_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
public const uint WIA_DPC_FIRST = WIA_DPA_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
//
// Scanner only device properties (DPS)
//
public const uint WIA_DPS_FIRST = WIA_DPC_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
public const uint WIA_DPS_DOCUMENT_HANDLING_STATUS = WIA_DPS_FIRST + 13;
public const uint WIA_DPS_DOCUMENT_HANDLING_SELECT = WIA_DPS_FIRST + 14;
}
 
/// <summary>
/// Use scanner to scan an image (with user selecting the scanner from a dialog).
/// </summary>
/// <returns>Scanned images.</returns>
public static List<Image> Scan()
{
WIA.ICommonDialog dialog = new WIA.CommonDialog();
WIA.Device device = dialog.ShowSelectDevice(WIA.WiaDeviceType.UnspecifiedDeviceType, true, false);
 
if (device != null)
{
return Scan(device.DeviceID);
}
else
{
throw new Exception("You must select a device for scanning.");
}
}
 
/// <summary>
/// Use scanner to scan an image (scanner is selected by its unique id).
/// </summary>
/// <param name="scannerName"></param>
/// <returns>Scanned images.</returns>
public static List<Image> Scan(string scannerId)
{
List<Image> images = new List<Image>();
 
bool hasMorePages = true;
while (hasMorePages)
{
// select the correct scanner using the provided scannerId parameter
WIA.DeviceManager manager = new WIA.DeviceManager();
WIA.Device device = null;
foreach (WIA.DeviceInfo info in manager.DeviceInfos)
{
if (info.DeviceID == scannerId)
{
// connect to scanner
device = info.Connect();
break;
}
}
 
// device was not found
if (device == null)
{
// enumerate available devices
string availableDevices = "";
foreach (WIA.DeviceInfo info in manager.DeviceInfos)
{
availableDevices += info.DeviceID + "\n";
}
 
// show error with available devices
throw new Exception("The device with provided ID could not be found. Available Devices:\n" + availableDevices);
}
 
WIA.Item item = device.Items[1] as WIA.Item;
 
try
{
// scan image
WIA.ICommonDialog wiaCommonDialog = new WIA.CommonDialog();
WIA.ImageFile image = (WIA.ImageFile)wiaCommonDialog.ShowTransfer(item, wiaFormatBMP, false);
 
// save to temp file
string fileName = Path.GetTempFileName();
File.Delete(fileName);
image.SaveFile(fileName);
image = null;
 
// add file to output list
images.Add(Image.FromFile(fileName));
}
catch (Exception exc)
{
throw exc;
}
finally
{
item = null;
 
//determine if there are any more pages waiting
WIA.Property documentHandlingSelect = null;
WIA.Property documentHandlingStatus = null;
 
foreach (WIA.Property prop in device.Properties)
{
if (prop.PropertyID == WIA_PROPERTIES.WIA_DPS_DOCUMENT_HANDLING_SELECT)
documentHandlingSelect = prop;
 
if (prop.PropertyID == WIA_PROPERTIES.WIA_DPS_DOCUMENT_HANDLING_STATUS)
documentHandlingStatus = prop;
}
 
// assume there are no more pages
hasMorePages = false;
 
// may not exist on flatbed scanner but required for feeder
if (documentHandlingSelect != null)
{
// check for document feeder
if ((Convert.ToUInt32(documentHandlingSelect.get_Value()) & WIA_DPS_DOCUMENT_HANDLING_SELECT.FEEDER) != 0)
{
hasMorePages = ((Convert.ToUInt32(documentHandlingStatus.get_Value()) & WIA_DPS_DOCUMENT_HANDLING_STATUS.FEED_READY) != 0);
}
}
}
}
 
return images;
}
 
/// <summary>
/// Gets the list of available WIA devices.
/// </summary>
/// <returns></returns>
public static List<string> GetDevices()
{
List<string> devices = new List<string>();
WIA.DeviceManager manager = new WIA.DeviceManager();
 
foreach (WIA.DeviceInfo info in manager.DeviceInfos)
{
devices.Add(info.DeviceID);
}
 
return devices;
}
 
}
}
</string></string></string>

I have been trying a lot to get ideas to develop a scanner app. I avoided using TWAIn because of its complexity. So i thought of implementing WIA. I tried executing this sample code, but it gives me a error saying " no WIA devices found".

I am using a EPSON EXPRESSION 1680 scanner.
please help me with this project....................need help

source : http://miljenkobarbir.com/using-a-scanner-without-dialogs-in-net/[^]