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Topics - foorgol

#1
Raw Video Postprocessing / PinkDotRemover tool 650D
June 15, 2013, 08:51:57 AM
I saw the pink / blue dots in the DNGs as well and I think I have a solution. Or even two (!) solutions...

I) The easy way: use RawTherapee (http://rawtherapee.com)

For those of you who don't know: RawTherapee is a really powerful open source tool for developing RAWs. Runs under Windows, Linux and Mac.

You can directly open a DNG-file and if you then go to the "Raw"-Tab, unfold the "Preprocessing"-section and check "Hot/Dead pixel filter", the disturbing dots will magically disappear. Okay, most of them. Before you do this, you should select a processing profile from the drop down list under the histogram, because selecting a profile resets your "Hot/Dead pixel filter" setting (and all other settings as well) with the profile's default.

RawTherapee can do batch processing, so you can convert a whole image sequence for a movie with just a few clicks.


II) The DIY way: start coding

I hacked a small command line tool that removes the pink pixels directly in the DNG file. It's written in Java, so it should run under Windows and Mac, although I developed it under Linux... but who knows...

Currently the program can only remove pixels in DNGs with 1280x720 resolution, because it uses pre-stored pixel locations. I "calibrated" it to my 650D, but I guess/hope the pixel positions are identical on all 650Ds. Here's an example:

Original DNG:


Modified DNG with dots removed:

(both JPGs developed with RawTherapee and identical settings)

If you want to play with the tool, here it is:
https://dl.dropboxusercontent.com/u/22843507/MagicLantern/PinkDotRemover.zip
Just run it like "java -jar PinkDotRemover.jar YourFile.dng". If you're lucky, the program creates a _YourFile.dng with removed dots. Files will be overwritten without confirmation. Currently the tool is just a quick hack without focus on security or stability... use it at your own risk and cross your fingers... :)

As you can see above, there are still a very few dots left which the tool doesn't remove yet. But that's only a matter of fine tuning.

I'll clean up the code tomorrow and upload the sources as well. If you're (rightfully!) hesitant to execute a stranger's JAR-files on your machine, you can compile the JAR yourself by then.

Here are a few sample DNGs to compare the original with the modified image:

https://dl.dropboxusercontent.com/u/22843507/MagicLantern/M3_before.dng
https://dl.dropboxusercontent.com/u/22843507/MagicLantern/M3_after.dng

https://dl.dropboxusercontent.com/u/22843507/MagicLantern/M4_before.dng (DNG for the JPG above)
https://dl.dropboxusercontent.com/u/22843507/MagicLantern/M4_after.dng (DNG for the JPG above)

https://dl.dropboxusercontent.com/u/22843507/MagicLantern/M5_before.dng
https://dl.dropboxusercontent.com/u/22843507/MagicLantern/M5_after.dng


Let me know what you think... if you think it's useful, I could extend the tool to batch-convert all DNGs in a directory... or to handle resolutions other than 1280x720...