Scanning - hw custom document size

I need to perform a scanning of areas which do not meet standard sizes of A3, A4 etc. Those scans have开发者_运维技巧 to be loaded and post processed by custom application. The rough idea of my colleague was to disassemble standard scanner and attach optics + electronic (somehow) to a custom device which will navigate it (continuously) through the area (the hardware guy ... I have no idea).

My questions are:

1. Does anyone tried the thing? Go or no go?
2. Who controls the region and sizes of the image/document? Scanner driver/firmware? Can it run in a mode where I say from application -> perform scan -> scanner runs through available area -> image data are returned when it hits the end? Or, someone has to define the area for the scanner and only those data are sent back?
3. Can be this non-standard setup controlled via standardizes APIs (TWAIN, WIA)?

Any suggestions/remarks are highly appreciated.

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The easiest way is to use TWAIN.

In TWAIN specification 2.1, you can search for TW_IMAGELAYOUT and DAT_IMAGELAYOUT. The DAT_IMAGELAYOUT operations control information on the physical layout of the image on the acquisition platform of the Source (e.g. the glass of a flatbed scanner, the size of a photograph, etc.).

However, it is not easy to write your own code to support TWAIN. You can use any TWAIN library to achieve that.