The simple idea to improve the scanning ability of Silverfas
PostPosted: Thu Nov 21, 2002 5:00 pm
1) In 6th version of Silverfast I found the very useful feature - multiscanning (my scanner is Microtek filmscan 35). But looking how this multiscanning is done I thought that there exists better solution than to scan 4,8,16-times the entire picture and then merging it into one (it takes time to move the scanning head, to return it back, and head positioning is not perfect from scan to scan). I think that better solution would be to scan each line 4,8,16 times and then only to move the head to the next line. This would shorten the total time because the scanning head would not return 4,8,16 times from the last line to the first as it is done in the current scanning procedure.
2) It is not very difficult to modify the multiscan procedure so that each pass would be done with different exposure (normal, overexposed and underexposed) and then merging the resulting sequence into the picture that has much more Dmax than the CCD of a scanner can afford. This procedure can easily be done with Adobe photoshop. Just scan 3 pictures, normal, overexposed and underexposed, then merge them adjusting the visibility of layers.
3) It is possible to combine 1st and 2nd procedures. So the procedure of scanning would look like this: scanner moves the head to the first line, then scans it 12 times (normal, overexposed, underexposed, normal, overexposed, underexposed,...), combines this into one image of first line, then moves to the second line, and so on. This wil produce the picture with significantly lower noise and higher Dmax.
2) It is not very difficult to modify the multiscan procedure so that each pass would be done with different exposure (normal, overexposed and underexposed) and then merging the resulting sequence into the picture that has much more Dmax than the CCD of a scanner can afford. This procedure can easily be done with Adobe photoshop. Just scan 3 pictures, normal, overexposed and underexposed, then merge them adjusting the visibility of layers.
3) It is possible to combine 1st and 2nd procedures. So the procedure of scanning would look like this: scanner moves the head to the first line, then scans it 12 times (normal, overexposed, underexposed, normal, overexposed, underexposed,...), combines this into one image of first line, then moves to the second line, and so on. This wil produce the picture with significantly lower noise and higher Dmax.