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DPX Conversions

Posted: Mon Apr 20, 2009 6:49 am
by egrillo
I am currently working on a research project for movies restoration.
We digitally acquire old positive films using an Arriscan machine. The result are 3k dpx files with 10bit log per channel.
We would like to use XnView in our preview process, especially in the dpx to avi conversion done to enable web preview of the acquired materials.
The XnView thumbnail browser preview of our dpx images looks quite dark and flat (seems insensible to the 10logto8lin dpx read option).
The single image view looks less dark but still flat (this time seems like logtolin is ok but display levels are not correct).
Applying the menu option: image/Map/Automatic level we obtain a better balanced image, good enought for our preview purposes and better than a subjective manual adjustment).
In order to obtain an avi preview, we convert dpx sequences to jpg and then jpg sequences to mjpg avi.
The problem is that using the XnView multiple image conversion to convert dpx sequences, the automatic level options produces nasty level fluctuation between frames because evidently the automatic level adjustment is done on every single image and not on image sequences.
The question is: is there any way to save the level correction made on a single image and then apply it to an image sequences?
It will be possibile for us to find a sample image for the calibration, determine the level adjustment and apply it to all other images of the same sequence.
Thank you for any help and for any oher suggestions on the best practices to handle dpx sequences with this fantastic tool.
Regards,
Enrico Grillo
Torino, Italia

Re: DPX Conversions

Posted: Mon Apr 20, 2009 12:03 pm
by xnview
egrillo wrote: The question is: is there any way to save the level correction made on a single image and then apply it to an image sequences?
If you open the dpx, and use levels to find the good value. You can after use it in batch convert.

Re: DPX Conversions

Posted: Mon Apr 20, 2009 5:13 pm
by egrillo
Thank you Pierre.
You are confirming me that the "Automatic level" works on the Black and White points that I can adjust using Image>Adjust>Levels?
The problem is: adjusting levels with the Image>Map>Automatic Levels gives a good result without uman intervention.
Is there any way to visualize the Black and White points established by the "Automatic level" function and apply them to the batch conversion?
Regards,
Enrico

Re: DPX Conversions

Posted: Tue Apr 21, 2009 8:21 am
by xnview
egrillo wrote:Is there any way to visualize the Black and White points established by the "Automatic level" function and apply them to the batch conversion?
Currently no way, but i can add a little box with these informations in a custom version...