Develop Reference

How to create fast duplex scanning with WIA C#?

i am new to WIA. And i have been asked to make scaning service scan faster and duplex. My current service scan one page, then put it in pdf and so on untill there is less then 20 pages(this number just a crutch used before me, will be glad if someone explane how to get "if there is any paper in there" variable). I started to dig and found docs on MSDN describing properties and after found this post describing duplex sanning, but with mysterious 5 in set. After I found this and figured out what i need WIA_DPS_DOCUMENT_HANDLING_SELECT to set to 0x205(FEEDER + DUPLEX + AUTO_ADVANCE). So I tried to setup them like this:
private static void SetProperty(Property property, int value)
{
IProperty x = (IProperty)property;
Object val = value;
x.set_Value(ref val);
}
...some code...
foreach (Property prop in device.Properties)
{
//LOGGER.Warn(prop.Name);
//LOGGER.Warn(prop.PropertyID);
switch ((Int32)prop.PropertyID)
{
// Document Handling Select
case 3088:
SetProperty(prop, 517);
break;
// Pages
case 3096:
SetProperty(prop, 1);
break;
}
}
And it did't worked for me... It just stuck on setting... Can Somebody explain how to setup AUTO_ADVANCE and DUPLEX props? Or maybe "make scanning faster and duplex" need something more then just AUTO_ADVANCE and DUPLEX and my perception about them is wrong? Or I should considering "ISIS / TWAIN (Windows XP / Vista / 7 / 8 / 8.1 / 10)" string in my scan description and use other libraries?
(Window 10, Canon DR-M160||, DR-M160 & DR-M160II Driver for Windows)
and also here is the current fetch function:
public List<ImageFile> FetchImageList()
{
List<ImageFile> imageList = new List<ImageFile>();
//bool hasMorePages = true;
int testcount = 0;
while (testcount >= 0)
{
testcount--;
WIA.Device device = FindDevice(_deviceId);
if (device == null)
{
LOGGER.Warn("Scanner device not found");
return null;
}
// get item
WIA.Item scanItem = device.Items[1] as WIA.Item;
LOGGER.Debug($"ScanItem: {scanItem.ItemID}");
try
{
foreach (Property prop in device.Properties)
{
//LOGGER.Warn(prop.Name);
//LOGGER.Warn(prop.PropertyID);
switch ((Int32)prop.PropertyID)
{
// Document Handling Select
case 3088:
LOGGER.Warn("here");
SetProperty(prop, 517);
LOGGER.Warn("here");
break;
// Pages
case 3096:
SetProperty(prop, 1);
break;
}
}
// scan image
WIA.ICommonDialog wiaCommonDialog = new WIA.CommonDialog();
WIA.ImageFile image = (WIA.ImageFile)scanItem.Transfer(WIA.FormatID.wiaFormatPNG);
imageList.Add(image);
LOGGER.Warn("Front");
//get back side
image = (WIA.ImageFile)scanItem.Transfer(WIA.FormatID.wiaFormatPNG);
imageList.Add(image);
LOGGER.Warn("Back");
}
catch (Exception e)
{
throw (e);
}
}
return imageList;
}

Well... I tried to make duplex scan without AUTO_ADVANCE and got HRESULT: 0x8000FFFF (E_UNEXPECTED) on Transfer call. According to this post(even though that was on Windows 7) I guess there is no way to solve this for me by using WIA, still hope there will other suggestions...
Solved problem
I used saraff.twain and it worked for me:
- git page :https://github.com/saraff-9EB1047A4BEB4cef8506B29BA325BD5A/Saraff.Twain.NET
good library with grate wiki page.(Also have similar library for .net 4.6.1)

When using System.IO.Stream, how can I avoid OutOfMemoryException?

I am making a scanning component, but when I set a high resolution for the document (600 dpi), I tend to get System.OutOfMemoryException after just 1 or 2 scans.
My code is as follows
public ScannedImage SaveScannedImage(DataTransferredEventArgs e)
{
if (e == null) throw new IOException();
BitmapSource fullResImage;
using (var fullResImageStream = e.GetNativeImageStream())
{
fullResImage = fullResImageStream.ConvertToWpfBitmap(e.ImageInfo.ImageWidth, e.ImageInfo.ImageLength);
}
BitmapSource lowResImage;
using (var lowResImageStream = e.GetNativeImageStream())
{
lowResImage = lowResImageStream.ConvertToWpfBitmap(800, 0);
}
return new ScannedImage(lowResImage, fullResImage);
}
It is usually happening at the
using (var lowResImageStream = e.GetNativeImageStream())
Help would be much appreciated.

What you see may be caused by large object heap (LOH) fragmentation.
That is hard to avoid, but you can compact the LOH explicitely.
GCSettings.LargeObjectHeapCompactionMode =
GCLargeObjectHeapCompactionMode.CompactOnce;
GC.Collect();
Also, make sure you run as a 64 bit process. Turn of the "Prefer 32 bit" option if it is on.
For more information, you might want to read
https://msdn.microsoft.com/en-us/library/system.runtime.gcsettings.largeobjectheapcompactionmode.aspx
https://blogs.msdn.microsoft.com/ericlippert/2009/06/08/out-of-memory-does-not-refer-to-physical-memory/

OpenCL Cloo: Out of Resources Error

While running some test code in OpenCL (using Cloo C#), I started getting these OutOfResource errors from OpenCL and sometimes Unity just crashes entirely before I get an exception. I am basically re-calling a kernel function over and over with varying number of global/local work items to check timing. I leave the arguments the same and call the kernel starting with 2x2x2 global and 2x2x2 local and iterating uperwards checking only valid sizes. It works fine occasionally, but most of the time it completes about 30 or 40 Execute() calls and then crashes on the next Execute() call.
Note: Execute refers to the OpenCL.dll on the computer. The stack trace Unity returns is NULL I assume because of the native code.
Anyone have any idea what could be causing this?
Note: This version of Cloo is Cloo-Unity from GitHub and I am using it in Unity. The equivalent OpenCL function being called when I get the error is clEnqueueNDRangeKernel(), but it is called Execute() in Cloo.
Code Sample:
//Setup inputs one time...
foreach (var input in p_inputs)
{
inputs.Add(input.Function, input);
profiles.Add(input.Function, new RunProfile(input.Function, input.Weight));
input.Input.Prepare(package[input.Function]);
}
//Profile...
DateTime start;
int g_state = 0;
int l_state = 0;
long[] g = new long[3] { 2, 2, 2 };
long[] l = new long[3] { 2, 2, 2 };
while(g[0] * g[1] * g[2] < Device.MaxWorkGroupSize)
{
l[0] = 2; l[1] = 2; l[2] = 2; l_state = 0; //Reset locals
bool proceed = true;
while(proceed)
{
proceed = (l[0] != g[0] || l[1] != g[1] || l[2] != g[2]);
if (CLUtilities.ValidateExecutionParameters(Device, g, l))
{
Debug.Log("Profiling Start: " + g.ToEnumeratedString() + " / " + l.ToEnumeratedString());
foreach (var profile in profiles)
{
start = DateTime.Now;
//Exception here when on (g=6x4x4, l=6x4x4)
package.Execute(package[profile.Key], g, l);
package.Commands.Flush();
package.Commands.Finish();
float time = (float)(DateTime.Now - start).TotalMilliseconds;
profile.Value.AddRun(g, l, time);
}
Debug.Log("Profiling Ending: " + g.ToEnumeratedString() + " / " + l.ToEnumeratedString());
}
l[l_state] += 2;
l_state = (l_state == 2) ? 0 : l_state + 1;
}
g[g_state] += 2;
g_state = (g_state == 2) ? 0 : g_state + 1;
}

Sorry i cannot comment cause less than 50 rep. but which operating system do you use? gpu? driver?
i got similar problems caused by opencl.dll i used win10 and Nvidia (x64).
Also have a look on https://social.technet.microsoft.com/Forums/en-US/85680348-c2c4-40bc-9f39-9dcfeea331c0/windows-10-opencldll-error?forum=win10itprogeneral
It seems that there is/was a issue with the memory compression in win10.
My problem was caused by updating win7 to win10, without updating the nvidia drivers.

I just got back around to posting this, but the issue turned out be related to the fact that I didn't recall Kernel.SetArgument() each time I called the Execute() method. I originally did this because I was worried it would re-copy the buffer, but as it turns out the buffer copy doesn't occur in this method anyway (so the overhead was small anyway).

Does your nvidia graphics card for display?
If nvidia is main graphics card, you have to edit registry to turn off watchdog.
for windows 7
system/current/control/graphicsdriver
TdrLevel(DWORL) : 0

Out of memory exception. May be from webservice

I got out of memory exception problem for 4 months. My client use webservice, they wanna me test their webservice. In their webservice, there is a function call upload. I test that function on 1500 users who uploaded at the same time. I tried garbage collection function of visual studio (GC). With 2mb of file, there is not exception, but with 8mb of file there is still out of memory exception. I have tried many times and a lot of solutions but still happened. I gonna crazy now. When upload is on going, I watched memory of all test computers but memory is not out of. So I think that problem is from webservice and server. But my client said that i have to improve those reasons which is from webservice and server to them. I'm gonna crazy now. Do you guys have any solotions for this? In additional, Our client does not public code, I just use webservice's function to test. Additional, I have to use vps to connect their webservice and network rather slow when connect to vps.
I have to make sure that my test script doesn't have any problem. Here is my test script to test upload function.
public void UploadNewJob(string HalID, string fileUID, string jobUID, string fileName, out List errorMessages)
{
errorMessages = null;
try
{
int versionNumber;
int newVersionNumber;
string newRevisionTag;
datasyncservice.ErrorObject errorObj = new datasyncservice.ErrorObject();
PfgDbJob job = new PfgDbJob();
job.CompanyName = Constant.SEARCH_CN;
job.HalliburtonSalesOffice = Constant.SEARCH_SO;
job.HalliburtonOperationsLocation = Constant.SEARCH_OL;
job.UploadPersonHalId = HalID;
job.CheckOutState = Constant.CHECKOUT_STATE;
job.RevisionTag = Constant.NEW_REVISION_TAG;
var manifestItems = new List();
var newManifestItems = new List();
var manifestItem = new ManifestItem();
if (fileUID == "")
{
if (job.JobUid == Guid.Empty)
job.JobUid = Guid.NewGuid();
if (job.FileUid == Guid.Empty)
job.FileUid = Guid.NewGuid();
}
else
{
Guid JobUid = new Guid(jobUID);
job.JobUid = JobUid;
Guid fileUid = new Guid(fileUID);
job.FileUid = fileUid;
}
// Change the next line when we transfer .ssp files by parts
manifestItem.PartUid = job.FileUid;
job.JobFileName = fileName;
manifestItem.BinaryFileName = job.JobFileName;
manifestItem.FileUid = job.FileUid;
manifestItem.JobUid = job.JobUid;
manifestItem.PartName = string.Empty;
manifestItem.SequenceNumber = 0;
manifestItems.Add(manifestItem);
errorMessages = DataSyncService.Instance.ValidateForUploadPfgDbJobToDatabase(out newVersionNumber, out newRevisionTag, out errorObj, out newManifestItems, HalID, job, false);
if (manifestItems.Count == 0)
manifestItems = newManifestItems;
if (errorMessages.Count > 0)
{
if (errorMessages.Count > 1 || errorMessages[0].IndexOf("NOT AN ERROR") == -1)
{
return;
}
}
//upload new Job
Guid transferUid;
long a= GC.GetTotalMemory(false);
byte[] fileContents = File.ReadAllBytes(fileName);
fileContents = null;
GC.Collect();
long b = GC.GetTotalMemory(false);
//Assert.Fail((b - a).ToString());
//errorMessages = DataSyncService.Instance.UploadFileInAJob(out transferUid, out errorObj, job.UploadPersonHalId, job, manifestItem, fileContents);
DataSyncService.Instance.UploadPfgDbJobToDatabase(out errorObj, out versionNumber, job.UploadPersonHalId, job, false, manifestItems);
}
catch (Exception ex)
{
Assert.Fail("Error from Test Scripts: " + ex.Message);
}
}
Please review my test code. And if there is not any problem from my test code, I have to improve reason is not from my test code T_T

My guess would be that you hit the 2 GB object size limit of .NET (1500 * 8MB > 4GB).
You should consider to change to .NET 4.5 and use the large object mode - see here - the setting is called gcAllowVeryLargeObjects.

GDI Printing In C# Memory Leak Woes, Unexplained Errors, Inability to thread

We are using Win32 calls to the GDI Printing API to print graphics.
I've noticed that on certain PCL print queues, we leak GDI memory when printing. As far as I can tell everything is being disposed of properly. Not being an admin at my company it's rather difficult for me to tell which drivers print queues are using. PCL6 drivers appear to be the main culprit. Other seemingly unrelated issues I've seen:
System.ComponentModel.Win32Exception: The data area passed to a system call is too small
System.ComponentModel.Win32Exception: The operation completed successfully
var hdc = GdiPrintWin32.CreateDC(IntPtr.Zero, printerName, IntPtr.Zero, IntPtr.Zero);
if (hdc == IntPtr.Zero)
throw GetError("Device context failed for {0}", printerName);
try
{
if (GdiPrintWin32.StartDoc(hdc, ref doc) <= 0)
throw GetError("Failed to start print job");
This logic is currently being done in a WCF hosted inside a Windows service. When I set the instance mode to single and hammer it, I only get it the first couple calls; when I set the instance mode to per call, it's a lot easier to reproduce.
I've also seen errors where basically no calls can go through to the service for about 20 minutes and requires a restart to fix. I notice that after stopping the service there are Windows Event logs to the effect of:
2 user registry handles leaked from \Registry\User...: Process 3792 (\Device\HarddiskVolume1\Windows\System32\rundll32.exe) has opened key \REGISTRY\USER... Process 3792 (\Device\HarddiskVolume1\Windows\System32\rundll32.exe) has opened key ...\Software\Hewlett-Packard\HP SSNP
Basically it's been nothing but a nightmare for us. Has anyone had any experience with anything like this?
The guts of the code we're using to print are:
var doc = new Docinfo { DocName = printJobName };
// create a device-context
var hdc = GdiPrintWin32.CreateDC(IntPtr.Zero, printerName, IntPtr.Zero, IntPtr.Zero);
if (hdc == IntPtr.Zero)
throw GetError("Device context failed for {0}", printerName);
try
{
if (GdiPrintWin32.StartDoc(hdc, ref doc) <= 0)
throw GetError("Failed to start print job");
foreach (PrintingMetafile metafile in pages)
{
var bytes = metafile.GetBytes();
// load the bytes to a memory location and get the pointer
var inMemRef = GdiPrintWin32.SetEnhMetaFileBits((uint)bytes.Length, bytes);
if (inMemRef == IntPtr.Zero)
throw GetError("Failed to create EMF in memory");
// Get the pixel coordinates of the paper
var x = 0; // GdiPrintWin32.GetDeviceCaps(hdc, HORZSIZE);
var y = 0; // GdiPrintWin32.GetDeviceCaps(hdc, VERTSIZE);
var hres = GdiPrintWin32.GetDeviceCaps(hdc, HORZRES);
var vres = GdiPrintWin32.GetDeviceCaps(hdc, VERTRES);
var rect = new Rect { Left = x, Top = y, Right = hres, Bottom = vres };
if (GdiPrintWin32.StartPage(hdc) <= 0)
throw GetError("StartPage failed");
if (GdiPrintWin32.PlayEnhMetaFile(hdc, inMemRef, ref rect) == 0)
throw GetError("PlayEnhMetaFile failed");
if (GdiPrintWin32.EndPage(hdc) <= 0)
throw GetError("EndPage failed");
if (inMemRef != IntPtr.Zero)
{
GdiPrintWin32.DeleteEnhMetaFile(inMemRef);
}
}
if (GdiPrintWin32.EndDoc(hdc) <= 0)
throw GetError("Failed to finish print job");
}
finally
{
GdiPrintWin32.DeleteDC(hdc);
}