Support Center

Uneven scanning quality

David Rosenthal Jul 10, 2012 12:37PM EDT

This is a follow up question to a prior post. I have included it below.

You had suggested I change the scan to greyscale. In my VB program I added
If ImTwain1.NegotiateCapability(Capabilities.Pixel_Type, 1) Then
and the image improved but the image size went from 15K to 750K. I was hoping for something smaller.

I was able to narrow down the condition that caused the poor scan. I am scanning a yellow page, with printed characters and handwriting. If the document has any handwriting in blue ink, it causes the whole scan to be poor. When I white out the blue writing, the scan is fine.

Any hints as to what to do?

I am scanning documents that have both printed and handwritten B/W characters. Some documents scan fine while with others the printed and handwritten characters are very light. I use the following settings and save the file as a tif image.

If ImTwain1.NegotiateCapability(Capabilities.X_Resolution, 120) Then
End If
If ImTwain1.NegotiateCapability(Capabilities.Y_Resolution, 120) Then
End If
If ImTwain1.NegotiateCapability(Capabilities.Pixel_Type, 0) Then
End If

Any suggestions as to what to change?


1 Data Techniques Response

Up 0 Rated Down
DTI Support  Data Techniques Employee Jul 10, 2012 03:47PM EDT


One option would be to scan as greyscale but then use our ImageMan.Net components to dither the image to black & white ie 1 bit. This may improve the quality in a scanner independent manner. The other option is to experiment with the brightness and contrast capabilities to better scan the blue on yellow.

Blue ink can be an issue particularly on a colored background.

Thanks for your interest in our products and please let us know if you have any questions.

Data Techniques Support

This question is closed to new answers.

Contact Us