RAW File Color Info

[Alan N]

It is my understanding that in a RAW output file, from a camera, the only color information is the hue of the color and that it does not contain any saturation or luminance data. Is this correct, or am I mis-informed?

[pnodrog]

I think you should read the CinC tutorial on understanding a digital camera sensor. https://www.cambridgeincolour.com/tu...ra-sensors.htm The raw file contains the detected light levels for each photo site. It is up to the RAW converter software to extract how these levels as taken through the Bayer filter mask are converted to a colour image. The hue etc are not truly defined until the conversion has been done.

[Alan N]

It is my understanding that the three photo sensors for each pixel collects certain amounts of light. The amount of light collected in the red, green, and blue sensors then determines the color hue.

[DanK]

"certain amounts of light" is luminance data. Please start with the link Paul suggested and ask about things that article leaves unclear to you.

[xpatUSA]

It is my understanding that the three photo sensors for each pixel collects certain amounts of light.

The only sensor that has three photo sensors for each pixel is the Foveon sensor used in Sigma cameras.

With respect to any other sensor type, you have been misinformed.

[xpatUSA]

"certain amounts of light" is luminance data.

There is a time element, Dan.

An amount of light at the sensor is exposure, as in H = illuminance times shutter-time = lux-sec.

[pnodrog]

It is my understanding that the three photo sensors for each pixel collects certain amounts of light. The amount of light collected in the red, green, and blue sensors then determines the color hue.

Ignoring the Foveon sensor which is similar to what you write during the raw conversion for most sensor types the pixel colours are determined from four (at least) RGBG filtered wells not just three sensor wells. However during the conversion from raw the RGB values will be determined for each pixel. Once converted provided no compression is used the resulting image file will be about three times the size of the raw file.

[Manfred M]

Alan - i would have to suggest that you have an incomplete understanding of what colour is.

First of all, the raw data that your camera captures is just that; individual R G G B values that have to be assembled into a colour image before it can be viewed. As others have noted that includes a de-mosaicing process as well as assigning a colour temperature and colour space.

When we use the word "hue", that is just another way of saying "colour". When we discuss "saturation", we are writing about the purity of the colour and lightness is how light or dark the colour is. HSL was a common colour model in the past and is definitely still in use.