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Hello I'm trying to understand how white balance is calculated during dng creation. I know that all info are inside the matrix AsShotNeutral , that represents white balance and tint inside a DNG. What I do not understand is how this matrix is calculated from camera? If I have the color matrices and forward matrices and the correct white balance expressed in Kelvin temperature how can I convert all these informations and build the AsShotNeutral matrix? Thank you, I'm very confused about what color space is used. I've tried to use XYZ color space without success, because I don't find enough information about DNG and white balancing.

Philip
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  • Have a look at page 80 from [the DNG manual](http://www.adobe.com/content/dam/Adobe/en/products/photoshop/pdfs/dng_spec_1.4.0.0.pdf) (Translating WB to Camera Neutral coords) – A_A May 25 '16 at 14:08
  • Thanks already read and implemented but even if I successfully found asShotNeutral white balance and above all tint are wrong. In DNG specs they speeks about XY color , to get this value I've used McCamy's formula to convert RGB mean of histogram to get Kelvin and these XY, could be this the problem? – Philip May 25 '16 at 21:05
  • Alright, just to clarify, are you trying to adjust the white balance of the image overall (with respect to "white") or correct the white balance to get rid of a specific tint? Actually, in both cases all you have to do is adjust the "power" of each band's histogram with respect to the RGB values of the tint correction (or max). How do you go from Kelvin to RGB? – A_A May 28 '16 at 16:07
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    Okay well maybe I've wrong something here: I've a camera that shots pure RAW files. These RAW should be converted in DNG , conversion is okay . To calculate neutral matrix I took the mean value of RGB histogram in live preview, then use these 3 values with McCamy's formula to calculate correct Kelvin (this step is right too). Now the problem is, how convert this correct Kelvin to asShotNeutral? I've tried to use Adobe dng spec but they speeks about XY coordinates that I don't understand what they are, should I convert kelvin in another format? – Philip May 29 '16 at 07:51
  • I'm voting to close this question as off-topic because it relates to camera white balance algorithms and would be better suited to another site – talonmies Jul 24 '16 at 11:42

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