Magenta edge tinging at high ISO and a possible solution...

Started Aug 17, 2009 | Discussions thread
GordonBGood Veteran Member • Posts: 6,308
PROGRESS: You might like to try this...

To all,

I apologize for not getting this finished but I have re-thought the correction based on the hot sensor files I received from godfrog. I had planned on doing an overall offset correction to the overall black level but it seems that this level is not related to the masked black areas and varies relative to their level depending on temperature/exposure time. Accordingly, I will only do a relative offset adjustment in order to not erroneously increase overall image contrast (ie try to make the black's too black), as the actual overall black level can be adjusted in raw conversion.

In order to show that this is not vapour-ware, I have released version 0.5.0.0 to my Live Spaces account with all correction turned off, as per the following link:

http://cid-610bb9d47b109171.skydrive.live.com/self.aspx/Distributed%20Programs/Pentax%20K20D%20Raw%20Tinge%20Correcter.zip

The purpose of the release is pretty well explained in the following excerpt from the ReadMe.txt file in the ".zip" distribution, which I encourage you to read, excerpt as follows:

"The current version 0.5.0.0 does absolutely nothing at all other than to demonstrate the user interface and allow potential users to confirm that they have the required pre-requisites of the program. It currently only works for DNG files directly from the camera or from DNG -> DNG conversions to uncompressed DNG format and not for PEF's converted to DNG's as that strips the border photosites or for compressed DNG's as converted from the uncompressed camera DNG's, as those are not yet supported. Currently, PEF files are not even searched for. Since the correction algorithm has been turned off as it is still being debugged, the output source files are exactly the same as the input source files except that the DNG AsShotNeutral tag information has been scaled up by a factor of 32 in order to more accurately "smudge" the white balance after the correction has actually been done. Under Windows, you can do a file comparison by using "fc b %f1 %f2" where %f1/2 are the file path\file name of the source and destination files respectively."

Try it to get ready and sorry for the delay.

Regards, GordonBGood

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