LibRaw technical support

Stable LibRaw versions: technical support, errors, API questions

NEF missing values

I used libraw to decode NEF images and looked at the r, g, b values. It turns out that certain r and b values never occur. I.e., some histogram values are zero.

In fact, the pattern of zeros is very regular. So for red, we have no samples with values 5, 14, 23, 33, 42, 51, 61, 70, 80, 89, 98 ... etc. For blue, there are no samples with values 4, 12, 20, 28, 36, 44, 52, 60, 68, 76, 84, 93.

Every 9th or 10th red value is missing. Every 8th or 9th blue value is mission.

The images were taken in 14 bit mode on a Nikon D7000.

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Using only green pixels to create final image (discard red and blue)

Hi,

I was hoping for some advice on how to have libraw completely discard the red and blue pixels and only use the green pixels to interpolate for the final image. This is for a scientific application. I have done a fair amount of research and I believe there is no way for me to do this without modifying the source code. That is fine with me.

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Gamma correction in Libraw

For the life of me, I cannot clarify my mind about how gamma correction/expansion is managed in libraw/dcraw and in general in a color management chain. Or maybe, I have an idea that has to be confirmed/rejected.

I assume human eyes introduce a gamma compression of about 0.45 and that this is canceled out by the viewer who observe an lcd screen with the same law.

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Compile once for i386 and x86_64

Hi, I am using libraw in one of my projects on Mac OS X.
I want to build my mac app in Xcode with architecture set to "Stand(32/64-bit Intel)", so that I need to compile libraw that can be linked in both 32 and 64 bits environment. But at this moment, I can compile either i386 version or x86_64 version, i can not make it compile once for both architectures.
Can anyone help me? Many thanks!

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