For many graphics systems, such as Photoshop, LUTs are not a colour management option. SpaceMan ICC will convert 3D LUTs into ICC profiles for use in such systems, for Look Management as well as Display Calibration.
When installed and started SpaceMan ICC will offer the chance to register and license. Registration details (and the option to register at a later date) are always available via the 'help\license' menu.
To convert a 3D LUT into an ICC Profile, first start a new ICC profile using the 'New Profile' button, or via 'File/New Profile' menu. This will build a basic ICC Profile starting point, with the minimum Header and Tag data.
Note: You can also load an existing ICC profile into SpaceMan ICC (v2 or v4) to enable it to be edited. Load an existing ICC profile either via the 'Open Profile' button, or via 'File/New Profile', or by dragging and dropping an existing ICC profile directly on-top of the main SpaceMan ICC window.
The above image shows a new starting ICC Profile with the Illuminant data shown - any Header or Tag information can be seen and edited by double clicking on the relevant information line.
With an ICC Profile active within SpaceMan ICC a 3D LUT can be selected and added to the profile via the 'Import 3D LUT' button. Select the 3D LUT format from the 'File Format' drop down list, activating the 'Clip out of range values' if required.
The required Class of Profile can also be set, as well as the option to 'Build VCGT Tag' for use within a graphics card for direct 1D LUT based grey scale display management.
Note: For normal use within the likes of Photoshop for Look Management via the generation of an ICC profile that matches an original 3D LUT, the 'Input+BToA Tag' option is the standard one to use. For display calibration the 'Display' option is the correct one to use.
(Input profiles actually only require an AToB Tag, but some graphics systems struggle with such profiles, hence the 'Input+BToA Tag' option.)
The 'RGB Space' option should be used to match the expected colour space within the graphics program to be used. The most common selection will be sRGB, with Encoding, as for most graphics programs, such as Photoshop, this will be expected colour space.
Note, the use of Encoding Gamma for image manipulation is not correct, but as this is how such graphics programs work with ICC profiles it is a necessary evil for SpaceMan ICC.
The 'Load Cube' button can then be used to select the specific 3D LUT to load, via a folder navigation window.
Note: If the LUT to be loaded does not appear in the File Format list it may be possible to load the LUT by selecting a similar format LUT type from the File Format list, allowing SpaceMan to parse the unknown LUT data correctly. For example, to load a Resolve .cube 3D LUT use the 'Iridas' LUT option, as that is the same format.
When a LUT has been loaded the 3D LUT can be seen visually within the cube display.
The 'View Gamma' button can be used to show a 1D RGB gamma profile of the 3D LUT, which is also the data that will be used within the VCTG Tag, if that option has been selected.
Selecting the 'Apply Cube' button will add the 3D LUT to the ICC Profile, be that a 'new' ICC profile, or an existing one that has previously been loaded, media white point, adding the correct media black point and LUT data tags to the profile.
The ICC profile should then be 'Named' using the internal 'ProfileDescriptionTag', listed within the 'Tag ID' window. This name is the one shown in any ICC profile list called up within ICC compliant programs, so it is important to use a unique name.
Select the 'Save Profile' button to save the profile, and enter the same name as used above in the 'ProfileDescriptionTag'. After saving, the 'Validate Profile' button can be used to versify the integrity of the new profile.
Note: SpaceMan ICC, by default, generates mono-direction ICC profiles, as the complex 3D LUTs used as the input data are next to impossible to invert, making such a function useless. The alternative LUT Tag (BToA or AToB, depending on the Class if ICC being generated) is populated with Null/Bypass data.
SpaceMan ICC can add a VCGT to the ICC profile, using a 3D LUT as the basis for the 1D VCGT data.
If the vcgtTag information line is double clicked a new window will open showing the VCGT data, both as a numerical list and as a Gamma Graph. The 'Apply' button will apply the VCGT to the active display, and the 'Reset Display Tables' button (monitor icon with green looping arrows, or the 'F5' key) will re-set the VCGT data - only when the vcgtTag window has been closed.
Note: This is the same operational functionality as SpaceMatch DCM.
As with any Graphics Card based calibration, the VCGT is based on 1D LUT data, not 3D, so the calibration is gamma and colour temperature (grey scale) only, as Graphics Cards cannot control display gamut.
This is true for ANY Graphics Card or Windows OS wide (ICC) calibration.
(Mac can perform OS wide Gamma and Gamut ICC based calibration, but suffers a number of other colour related issues that makes it impossible to rely on such colour calibration.)
SpaceMan ICC Features and Options
SpaceMan ICC is really a bit of a 'Swiss Army Knife', with a range of tools and capabilities that can be used as needed. This means the actual capabilities of SpaceMan ICC are very difficult to pin-down, as the various tools can be used in a wide variety of ways.
If just making an ICC profile that matches an existing 3D LUT for use in the likes of Photoshop for Look Management the requirements for operation of SpaceMan ICC should be simple, and exactly as described here.
Note: the 'New Tag' button is presently not active . To load a different Tag into an ICC profile first export the desired tag from another ICC profile and load into the profile that lacks it.
Generating a Display Class ICC profiles is one of the obvious capabilities of SpaceMan ICC, converting an accurate 3D Calibration LUT into an ICC profile. The ICC profile will be a perfect match to the original 3D LUT.
A major benefit of the use of a v4 ICC profile with a LightSpace 3D LUT loaded into it is the ability to maintain calibration accuracy, as LightSpace has done all of the hard work in generating the calibration LUT, meaning the graphics program and associated CMM using the ICC has no processing to perform at all. It just passes the image through the 3D LUT data held within the ICC.
To generate a Display Calibration ICC profile first use LightSpace CMS to generate an accurate calibration 3D LUT. With the LUT generated use SpaceMan ICC to build a 'Display' class ICC profile, using the instructions above.
It is possible to use the VCGT option within SpaceMan to enable OS wide gamma/grey scale/white point calibration within Windows, via the 1D LUT capability of the graphics card. However, the graphics program will probably 'double-up' this correction when the 3D LUT held within the ICC profile is applied, requiring the VCGT to be disabled for accurate display calibration.
If you want to use the VCGT for OS wide gamma/grey scale/white point calibration, the 'doubling-up' can easily be avoided by generating a second 3D LUT within LightSpace that has no 1D component. The original 3D LUT 'with' the 1D component can then be imported into the ICC profile, with the 'Build VCGT Tag' option enabled to correctly build the VCGT. The second 3D LUT exported from LightSpace 'without' the 1D component can then be imported into the same ICC with 'Build VCGT Tag' disabled, replacing the 3D LUT component of the ICC for accurate gamma correction, removing the 'doubling-up' of the 1D LUT data.
To learn about removing the 1D LUT component from a 3D LUT see the SWAPPING LUT COMPONENTS section of the Advanced LightSpace CMS Operation page of the website.
An alternative to the Subtraction of the 1D component is to initially profile using a Grey Only profile, as only the 1D grey scale component is of interest, and generate an ICC with the VCGT included. Load the ICC, and with the VCGT active, re-profile using a large Cube based profile to re-profile the display. The generated LUT will therefore not contain the same duplicated 1D data, but will contain the 3D volumetric gamut data.
To Load the Calibration ICC profile into Windows use the 'Windows Colour Management' option, found via the 'Control Panel', after first installing the ICC profile by right clicking it, and selecting 'Install Profile'.
(A Google search will find instructions for the loading of Display Calibration ICC profiles for you Windows OS version.)
The ICC profile needs to be 'associated' with the display it will be calibrating, for example via 'Windows Colour Management', as described above, and activated via enabling 'Use Windows display calibration'. The calibration will then be loaded automatically on startup - including the VCGT, if the ICC was generated with one.
Note: As the ICC profiles generated by SpaceMan ICC use XYZ as the PCS Colour Space, some graphics systems will 'complain' about the profiles potentially being defective when used as DisplayClass profile. Photoshop is an example, complaining that 'The monitor profile 'xxxx' appears to be defective. Please rerun your monitor calibration software'. Such warnings can be ignored, as using XYZ as the PCS Colour Space is entirely valid.
Look Management is another obvious application for SpaceMan ICC, enabling Look LUTs, such as Film Emulation 3D LUTs, to be accurately converted into ICC profiles.
The process is basically as above, selecting 'Input+BToA Tag' as the Profile Type. For such Look Emulation ICC profiles it is not necessary to use the VCGT option, as that is redundant.
Rather than using the OS, Look Emulation profiles should be used within the graphic program. The following describes the use of Photoshop, outlining potential issue that can cause the applied ICC profile to 'look' wrong.