Raw has no color space. And it doesn't matter what you set your camera to (you're shooting Raw).
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Does a raw file have a color space?The question is, “Does a raw file have a color space?” Some answer no for various reasons. Some say that the raw file can not have a color space because it is monochrome and contains no color. Of course, no file can contain color, since color is a perception and exists only in the eye and brain. What raw files and RGB files do contain is color information in the form of tristimulus color values that are perceived as color when projected on the retina. The RGB file contains three color values per pixel, for a complete RGB representation. The raw file of a Bayer array camera
contains only one color per pixel, and the other two are interpolated from adjacent pixels in the demosaicing process. Nonetheless, color information is present in the raw file and does not magically appear during demosaicing.
The recognition that the raw file does have a color space is useful in understanding how raw files are processed. Examples with code are available in DCRaw and Dng_verify, a command line program written by Thomas Knoll.
In the DNG program and DCRaw, 3 by 3 matrix conversions are used to convert from the camera space to an internal working space, in the same fashion as one would convert from ProPhotoRGB to Adobe RGB. In the case of DNG, the working space is linear ProPhotoRGB, while in the case of DCRaw, it is apparently CIE XYZ. DNG uses the dng_matrix & CameraToPCS () function to determine the white point x,y values. Thus, it is apparent that the raw file contains all the elements of a color space, either explicitly or implicitly in the form of metadata, camera profiles, or other information. Furthermore, in the source code quoted below, Thomas Knoll refers to the “
camera native space” and “
camera color space”, which would indicate that he thinks that the camera does have a color space that is represented in the raw file and the camera profile.
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Appendix[/span]
RGB Matrix profile (example is aRGB) :Gamma 2.2
White point
K 6500
x, y: 0.3127, 0.3290
Primaries
x y
R 0.6400, 0.3300
G 0.2100, 0.7100
B 0.1500 0.0600
Raw FilePrimaries: determined by CFA filters and silicon spectral response, stored in camera profile
Gamma 1.0
White point: stored in tag to raw file
White point x, y: recovered by dng_matrix & CameraToPCS () function in DNG_verify
3 by 3 matrix for Canon 1Ds, used by DCRaw
6517,-602,-867,
-8180,15926,2378,
-1618,1771,7633
Code Extracts/*****************************************************************************/
// Copyright 2006 Adobe Systems Incorporated
// All Rights Reserved.
//
// NOTICE: Adobe permits you to use, modify, and distribute this file in
// accordance with the terms of the Adobe license agreement accompanying it.
/*****************************************************************************/
/* $Id: //mondo/dng_sdk_1_1/dng_sdk/source/dng_render.cpp#1 $ */
/* $DateTime: 2006/04/05 18:24:55 $ */
/* $Change: 215171 $ */
/* $Author:
tknoll $ */
/*****************************************************************************/
for (int32 srcRow = srcArea.t; srcRow < srcArea.b; srcRow++)
{
// First convert from
camera native space to linear PhotoRGB,
// applying the white balance and camera profile.
const dng_matrix & CameraToPCS () const;
/// Return the XY value to use for SetWhiteXY for a given
camera color space coordinate as the white point.
/// \param neutral A
camera color space value to use for white point. Components range from 0.0 to 1.0 and should be normalized such that the largest value is 1.0 .
/// \retval White point in XY space that makes neutral map to this XY value as closely as possible.
DCRAW
/*
Thanks to Adobe for providing these excellent
CAM -> XYZ matrices!
*/
{ "Canon EOS-1Ds Mark II", 0,
{ 6517,-602,-867,-8180,15926,2378,-1618,1771,7633 } },