Author Topic: changing black levels for color shit in timelapse  (Read 108 times)

skippy2008

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changing black levels for color shit in timelapse
« on: August 01, 2020, 07:05:37 PM »
Hello guys

First, sorry for my english, it' not my native language. I'll do my best

I have an issue with timelapse sequences that show color shift from frame to frame (going from green to magenta and vice versa). After researching on the web, i found out that it came from my camera that was not recording the same values for the RGB Black levels. The fix for this problem is to extract the metadata from a frame that has the correct tint, note the 3 values for "black level green, blue and red" and then batch processing all the frames of the sequence inputing those "good" values. I've tried to document myself to do so but its a pain in the ass and i really don't understand nothing at command-line application.

Please, is there someone that could help me by giving me the steps to do so ??
- extract metadata from a "good frame"
- input the same black level values for all the frames of the directory

I'm on Facebook groups where lots of people have the same issue than me but no-one find the solution/ I can help all these guys, if you tell me how to do it   lol

Im running on MacOS (with Terminal) but i assume the command must be the same on Windows or Mac ??

Hoping for your help. Thank you very much

StarGeek

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Re: changing black levels for color shit in timelapse
« Reply #1 on: August 01, 2020, 08:38:09 PM »
I'm assuming these frames are individual files and not part of an existing video?

Do you have a bad and good frame you can share with us so we can take a look?
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Phil Harvey

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Re: changing black levels for color shit in timelapse
« Reply #2 on: August 03, 2020, 09:30:46 PM »
What type of images are these, and from what camera model?

If you can see the black levels in ExifTool, then you can likely write them too.  Did you check the ExifTool output to see if they exist in your images?

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).