python & twain : access scanner CCD with TWAIN on line-by-line basis

Question

I'd like to build a spectrophotometer using the CCD of a desktop scanner as the detector.

TWAIN should allow me to do that via the existing USB interface of the scanner (i.e. removing the CCD from the scanner unit and just using it without the scanning hardware).

Are any of the existing python twain packages fine-grained enough to repeatedly access the single-line output of a desktop scanner CCD?

Answer 1

TWAIN doesn't let you read single lines from the device, it's a much higher-level API than that. Even when TWAIN is transferring buffers of image data, the driver will assume it has to apply various corrections to the data - such as, correcting for non-uniform lighting across the bar, which you would have to model and undo.

I think you'd be much better off searching for a USB interface to a CCD, or some kind of capture card that lets you talk more directly to your sensor. Lots of enthusiasts out there doing things along those lines.