Another suggestion for SANE2: In sane_control_option(), the info passed back in *i should allow the backend to ask for the preview to become invalid. I think this would be useful for backends which can change something fundamental (like exposure) that changes the way the image is scanned. This is not essential, it would just make the interface more idiot-proof: a frontend could mark the preview as invalid (with a red line through it or similar -- not by deleting the preview!) to indicate that the image to be scanned will be different from the one in the preview.
Therefore, how about SANE_INFO_INVALIDATE_PREVIEW ? We could also go for a more elaborate approach which allows the backend to request corrections to the preview. If, for example, red channel exposure is increased by a factor of 1.2, it would be possible to correct the preview without scanning a new one. (Note: this could be the exposure time of the scanner, which is independent of the LUTs.) Any suggestions? Andras =========================================================================== Major Andras e-mail: and...@users.sourceforge.net www: http://andras.webhop.org/ ===========================================================================