Re: SetCapability: ImagePhysicalHeight, ImagePhysicalWidth

Hi,

I am currently developing an application using the lead tools main eval 14.5 and twain to interface with a Ricoh IS450 scanner.

I am having a little bit of trouble setting the physical height and width of the scanned document, when I set the dimensions in inches to 11.73f x 17.00f (A3) the capability values are accepted without issue.  When I then modify the values to 8.30f x 11.70f (A4) or any other values I get an 'Invalid capability value' error.

Is this a limitation of my scanner in that it only handles the A3 size?  Or is this an issue with the lead tools?

I also have had issue with the Brightness and Contrast settings in that the values are accepted as expected but seem to have no effect on the resulting image.

 

Any help would be much appreciated.

Matt.

In the Twain 1.9 specification document, the topics for ICAP_PHYSICALHEIGHT and ICAP_PHYSICALWIDTH specify that "MSG_SET not allowed", which means these 2 capabilities are read-only. This is because the 2 capabilities give you the maximum allowed scan area, not the actual scan area for a particular acquire operation.
If your scanner's driver allows you to set a value, even if it's the correct maximum value, this means the driver is violating the standard.
If you want to specify a scan area, you can either control the margins (in the Twain properties) or use the Image Frames (ICAP_FRAMES) or the Image Supported Sizes (ICAP_SUPPORTEDSIZES) capabilities, if they are supported.

You can check these capabilities and the problem with the other capabilities, such as brightness and contrast by using a utility from the TWAIN working group called Twacker. You can set and get capabilities for scanners using this program, in addition to perform scanning. Please try it if you haven't done so already to make sure the problem is not in the driver. If you don't have it, you can get it from:
http://www.twain.org/sca...ification-and-tools.html

Use it to set and get the same capabilities and values that fail with LEADTOOLS. If you need help testing with it, or if you already tried it, please let me know.

Edited by moderator Thursday, October 6, 2016 5:04:37 AM(UTC)  | Reason: Not specified