Yep! That did the trick. No more auto rotate. I'll see if I can find a the 9.17 version of dcraw.Does the option '-t 0' (flip image = none) help with the auto rotate?
Yep, you can leave the RAW files bayered and let another program take care of it, if you trust it to do a good/better job (you will have to make sure you get the bayer matrix right).Rowland wrote:I take it that the -W option is not required if the -4 option is used. That is, dcraw -v -r 1 1 1 1 -4 -T -S 32767 -k 0 -o 0 *.CR2 produces an image with no automatic gamma increase.
The -D option extracts pure raw data. How might this apply to our cause for as near as unadulterated data? It seems this is useful for analysis?
A closer look and I think the options I'm seeking are $dcraw -v -d -4 -T -o 0 *.CR2 which should produce a 16bit linear tiff, Bayer, monochrome, no auto gamma increase and no black point set. Not sure if this is the PI preset - away from computer a few days. Images aee converted to RGB at deBayer, which saves memory and simplifies calibration.
I think that debayer is done first and calibration later (I cannot see the source for any program, but that is definitely how I would do it!).Rowland wrote:Calibration sits between the dcraw linear and deBayer outputs
Yep, a stacking algorithm based on statistical rejection should take care of removing trailing, and if the user has properly dithered in between frames, dead or hot pixels will also have been taken care of.Rowland wrote:Pixel rejection is necessary however, for removing satellite trails and so on
Makes sense to me!Interestingly, the recommended manual PI preprocessing for DSLR data is to use the -r 1 1 1 1 option. This is not favoured by some, however, rather than indicating that monochrome is personal preference, the argument has been presented authoritatively - by well meaning people - as the preprocessing default, which has generated confusion. The main advantage of monochrome calibration is memory and speed.