Re: Way to Control AcquireFast Image Number

Is there a way to set the starting image number when using acquirefast?

I need to use the same base name and call acquirefast multiple times to scan more documents. Acquirefast always restarts the image number at 1 so I end up overwriting previous scans.

Using V19 and C#.

Hello,

Each time you call AcquireFast(), the internal counter for pages would reset. You could subscribe to AcquireMultiPage Event, and this would give you the page number for each page that is scanned, but I do not believe this is what you are referring to.

The file name that you pass into the AquireFast() method is the file that will be written. Part of the speed gain from Fast TWAIN is the fact that the best settings are used for each scan, and when saving to file, the compression is done in the hardware. So LEADTOOLS does not control that. LEADTOOLS indicates what the file name is that should be created, but the scanner itself handles the writing of the file. Furthermore, the TWAIN specifications dictate that when the source is writing to a file (with file transfer mode enabled), it should create the file if it does not exist or overwrite the file if it does exist. There isn't any option within TWAIN for appending to an existing file.

If you need to append scans together, you could either look at using a feed loader if the scanner hardware has one, or you could create multiple files with similar base file names (as temporary files). After scanning has completed, you could then combine these files together with RasterCodecs.Load() & Save(). There's a demo that ships with the LEADTOOLS SDK illustrating two ways how files can be combined together. It can be found through the shortcuts here:

[LEADTOOLS 19]\Shortcuts\File Formats\.NET Class Libraries\Multipage Conversions