Creating JPEGs from Camera RAW files

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reebear
Posts: 3
Joined: Wed Jun 19, 2013 2:36 pm

Creating JPEGs from Camera RAW files

Post by reebear »

Hi all,
we have a problem when converting Camera RAW files (such as Pentax PEF, Canon CRW, etc.) into JPEGs. When using
nconvert.exe -out jpeg -o "<outputFilePath>" -overwrite "<sourceFilePath>"
the JPEGs always have a reduced brightness. The RAWs are 48 bits (3x16) whereas the JPEGs are 24 bits (3x8).

Is there any way to keep the brightness somehow :?:

thanks a lot in advance and best regards
andreas
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xnview
Author of XnView
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Joined: Mon Oct 13, 2003 7:31 am
Location: France

Re: Creating JPEGs from Camera RAW files

Post by xnview »

Do you have tried raw_autobalance, raw_camerabalance or raw_autobright?
Pierre.
reebear
Posts: 3
Joined: Wed Jun 19, 2013 2:36 pm

Re: Creating JPEGs from Camera RAW files

Post by reebear »

Bonjour Pierre,

thanks for enlightening me!
Adding -raw_autobright and -raw_camerabalance to the commandline did the trick.

thanks a lot / merci bien
andreas :D
reebear
Posts: 3
Joined: Wed Jun 19, 2013 2:36 pm

Re: Creating JPEGs from Camera RAW files

Post by reebear »

Hi,

the other interesting bit is that - since we have tried the -raw_* parameters - RAW files with a size of e.g. 4044 x 6080 pixels turn into JPEGs of 2022 x 3040 pixels in size.
When adding the parameter -resize 100% 100% - the command-line parser of nconvert seems to ignore the first percent sign and creates a file with a width of 100 pixels - using -resize 100%% 100% (i.e. doubling the percent sign in the first value) does the trick, but I guess you know that already.
I did not find a way to create a JPEG of the RAW file's image size of 4044 x 6080 pixels. Any ideas?

Also - despite the fact that for JPEG, a quality setting of 100 should be default, setting it to -q 100 actually increases the filesize compared to omitting the parameter.

best regards
andreas
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oops66
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Joined: Tue Jul 17, 2007 1:17 am
Location: France

Re: Creating JPEGs from Camera RAW files

Post by oops66 »

Hello,
FI: In case of re-scaling ... a very interesting website about gamma error in picture scaling/re-scaling.
http://newsgroup.xnview.com/viewtopic.p ... 060#p58060
XnViewMP Linux X64 - Debian - X64