Please read How to create DCP color profiles for further instructions in case you want to contribute. New profiles are added exclusively based on user submission. Most provided DCP profiles are dual-illuminant (see below) and some provide tone curves and looks as well. Matching only works on the exact name of the camera (case-sensitive) as is present in the image metadata. It is possible to add your own DCP or ICC profiles to this folder. The available profiles are found in the dcpprofiles folder in your installation directory. RawTherapee ships multiple high-quality, custom-made, general-purpose DCP profiles that can be automatically matched when an image from a supported camera is opened. These can be tailor-made to specific scene conditions to provide the most accurate color rendition, or to generally improve upon the standard matrix profiles available. RawTherapee allows you to use custom DCP (Adobe DNG Camera Profile) or ICC (International Color Consortium) color input profiles. HDR applications usually require a predictable linear color response). This is important for several image processing operations and for example when exporting for further editing (e.g. Because no non-linear functions are applied to the data, the scene-referred linearity of the light intensities is kept intact. table-based DCP or ICC profiles) is its linearity. The benefit of a matrix profile over other profiles (e.g. However, the color accuracy is usually still good enough for very different light sources and white balances.
6500K) and provide the most accurate color reproduction if the scene illuminant matches the calibration illuminant. These matrices are specifically calibrated for a specific illuminant ( D65, i.e. The input profile consists of a square matrix (3×3 for RGB based sensors) that is multiplied with the pixel vectors of camera-native RGB values. There is one exception: when a DNG raw file has a ColorMatrix2 Exif tag and was not generated by the Adobe DNG Converter, the matrix from the Exif data is prioritized above all others.Īpplying an input profile is nothing more than a linear algebra operation on the image data. Hard-coded values provided by the dcraw library embedded within RawTherapee.The dcraw_matrix field in the camconst.json data file available in RawTherapee's installation directory.Which profile is embedded can be checked with GIMP for example.Ī conversion takes place based on profiled information from either of three sources, in decreasing priority: sRGB) will be assumed linear, making them look brighter. This means that gamma-encoded files (e.g. Note that selecting 'No Profile' for non-raw files bypasses the embedded color profile and the working profile will be assigned.
Applying no input profile is generally only useful for analytical purposes to show images in the camera's native RGB color space, or in extreme cases to prevent clipping of channels when the camera has recorded colors outside of conventional gamuts. No color conversion will take place and a unit transform of the image data is applied. RawTherapee's interface for choosing the input profile 1.1 No Profile There are several ways to apply an input profile. The input profile is applied to the image data at the beginning of RawTherapee's processing pipeline because most tools depend on it. Without a camera-specific input profile, accurate color representation is impossible. Elle Stone's article, DCamProf's documentation or How to create DCP color profiles. Such a profile is the result of the analysis of how specific colors and tones are captured, processed and represented as raw data by the camera (for more details, see e.g. This conversion requires an input profile made specifically for the camera. 3.12 Possible example of use to modify/improve the behavior of the Input profileĪn essential first step in raw processing is the faithful conversion of the camera sensor data to an internal RGB color space.3.11.1 Display Matrix XYZ-RGB - "Mat_xyz_bradford".3.11 How the "Primaries and White Point" algorithm works.3.7.1 Differences compared to a classic tone curve.
3.6 Where is it located in the toolchain pipeline?.3.5 Three main uses (with or without CIECAM).3.4 Which data and profiles are used or modified?.3.3 Use of data from the "CIE xy" diagram in Abstract profiles.