Le jeudi 4 mars 2010 17:13:12 Chris Berry, vous avez ?crit : > On 03/03/2010 06:03 AM, stef wrote: ... > Ok thanks guys, this seems to have done the trick! There is now a black > line down one side of the page (not sure if that is supposed to be there > or not) and the colours seem to be a bit grainy. I have attached photos > to the site page > (http://sites.google.com/site/bez625/updates-1/update040310), these show > the shading calibration and the latest current scan. > > If possible could you take a look and advise on how to sort out the > grainy parts of colour, im completely unsure myself :) > > Chris > Hello,
I think there are a couple of things to look. First compute_coefficient() can't handle case where averaging is enabled for CCD, either disable averaging it or improve the function. Then you'll have to find what the offset to feed as a parameter. To find it I usually give 0 offset, then I count the number of vertical lines between a dark line and a bright one. Because a dark line isn't corrected and another is applied the correction which turns it bright. Then I use this value as offset. With some trial and error you can have a good value. You may also look at the color matrix. Regards, Stef