Forum 'VintaSoft Twain .NET SDK Discussions'

Hi,

I am using AcquiredImage.IsBlank(Single) to determine if a scanned image is blank.I have noticed that the compression of the image changes to None once this code is executed.
I set device properties as below

  device.TransferMode = TransferMode.Memory;
  device.ShowUI = false;
  device.ShowIndicators = false;
  device.UnitOfMeasure = Vintasoft.Twain.UnitOfMeasure.Inches;
  device.DisableAfterAcquire = false;
  // enable duplex
  device.DocumentFeeder.DuplexEnabled = true;

  device.PixelType = PixelType.BW;
  device.ImageCompression = TwainImageCompression.Group4;
  //resolution
  device.SetResolution(300, 300);
  device.Acquire();

In debug mode i can see that the image compression is Group4, but immediately after execution of code in if statement below(this code is inside device_imageAcquired) image compression changes to None.

  if (e.Image.IsBlank(0.01f))
  {
  }

I need to know how to retain the compression set initially.

Veena

Hi Alex,

Thanks, We are not processing the image after scan.Below are the steps that we do.
1. Open device manager
2. Open device
3. set device properties
4. Scan/Acquire Image
5. During Image Acquisition check if image is blank
6. If not blank save image to disk.

Without compression the image size differs(almost doubles/triples when scanned in color) as compared to compressed image size.

Thanks

Thank you,yes i am using jpeg for color and group4 for B&W.