ImageGear for C and C++ on Windows v19.10 - Updated
Multi-stream Scanning
User Guide > How to Work with... > Common Operations > Scanning > ISIS Scanning > More ISIS Characteristics > Multi-stream Scanning

Some scanners come with a feature called "multi-stream" or “dual-stream". This feature allows you to scan a page once, but retrieve multiple versions of the scanned page (e.g., colored and grayscale). To use this feature, you must set the scanner to the required mode and acquire the scanned page sequentially using the ImageGear C/C++ API.

To set the scanner settings programmatically, use IG_ISIS_drv_send with the IG_ISIS_DRV_SWAP_WINDOWS command. The IG_ISIS_DRV_SWAP_WINDOWS command allows the application to change the values of parameters in the selected driver window.

If there is a single page in the scanner, the scanner is set to “multi-stream” mode and is expected to send a colored and a grayscale image. You can get both images by executing something like this:

C
Copy Code
#define BUFSIZE 8192
AT_ERRCOUNT Acquire(HISISDRV hDriver)
{
    // Invoke the pipe and scan the page
    return IG_ISIS_run_zone(hDriver, lpBuffer, BUFSIZE);
}