26 Feb
2008
26 Feb
'08
8:15 a.m.
der Mouse wrote:
In terms of overall processing, I suspect that a 400dpi lossless image (TIFF,
GIF etc.) is a lot more efficient (memory, disk, decoding) than the
corresponding 3200dpi JPEG though, despite JPEG's superior compression.
For PCBs I'd be tempted to do a (very) little post-scan processing I think,
just to introduce more blocks of uniform colour and therefore keep the
filesize down.
I've not done much with scanning of (populated) PCBs though, as every scanner
I've tried so far has been rather useless for the task (focus issues, I
suspect - removing the scanner glass and supporting the PCB a more sensible
height above the scan head would likely be a good idea)
cheers
Jules
It may very
well be case that a 600dpi scan using lossless
compression will be much cleaner and usable than a 3200dpi scan using
heavy JPEG compression.
I question the "much". JPEG uses 8x8 blocks, so a 3200dpi JPEG cannot
lose more information than a 400dpi lossless, and I'm not convinced a
3:2 difference is enough to earn that "much".