The Virtual Probe capability within ColourSpace can be used for more than just playing with virtual measurements.
The Virtual Probe can be used to build absolute profiles, as well as generate Profiling Patch Sets for use via the Export Selection and Add/Modify Points capabilities in higher license levels.
- All ColourSpace License Levels
- INF/XPT/PRO/CAL/LTE & LCN/CMN/LGN & HTX/HTP/HTL & DPS/ZRO
- Build Absolute Profiles
- Generate User Patch Sets
- Assess Reduced Gamut & Focused Patch Sets
- Test & Compare Different User Patch Sets
ColourSpace Integration
The Virtual Probe can be extremely useful, and opens up a range of possibilities for both testing and the generation of profile information that can be used elsewhere within ColourSpace.
The concept behind the Virtual Probe is fairly obvious, while at the same time providing some very useful capabilities.
Virtual Probe Settings
The Settings options provide specific Virtual Probe configurations.
OETF
The OETF drop-down allows the selection of any colour space - preset or user - to be used as the target for the Virtual Probe.
With higher ColourSpace license levels, it is possible to Double Right Click the OETF selection to open a Modify window, as available within the main Library options. The Modify window will allow transient changes to be made to the selected colour space, with all changes live updated enabling alternate colour space comparisons to be made, and new colour spaces to be saved into the Library.
As the Modify window is non-modal, it can be kept open and different comparisons made with different colour space settings.
As soon as the Modify window is closed, the colour space will default back to its original selection/settings.
Min Luminance (nits)
Min Luminance sets the nits value 0% black is mapped to.
Max Luminance (nits)
Max Luminance sets the nits value 100% white is mapped to.
Probe Adjustments
Probe Adjustments are generic probes settings, with consistent operation regardless of the probe in use.
Configure Matching
Probe Matching is used to match a Tristimulus to a Spectrometer, increasing the profile accuracy.
There are three different methods available for probe matching - ColourSpace's unique 4 Colour Volumetric Matching (FCVM), and Multi-point Volumetric Matching (MPVM), with the option to force the use of the traditional simple matrix method (FCMM).
Offset
Probe Offset enables a user to manually enter offset values for different probes/display combinations.
Perceptual Colour Match is a preferable approach.
Extra Delay
Extra Delay sets a delay time after the patch has changed before probe measurement starts, and can be set automatically via the Auto button, and manages signal path delays in the image pipeline.
Note: Some probe/settings/display combinations will not work accurately with the Auto function
Virtual Probe Capabilities
Unlike other calibration systems, the Virtual Probe capability within ColourSpace can be used for more than just playing with virtual measurements, with true viable functions being provided for the building and assessment of user patch sets, probe match verification, and more.
Absolute Profiles
The Virtual Probe can be used to build absolute profiles, which are basically technical profiles of any target colour space, and can be used for multiple applications, including as the basis for the generation of User Patch Sets.
To generate an absolute profile, simply set the Target Gamut/EOTF in Settings to the desired colour space, and set the OETF in Virtual Probe Settings to the same colour space, with the same Min/Max Luma values defined.
Move to the Characterisation menu, select the desired characterisation patch set, and press Start.
User Patch Sets
The Virtual Probe can also be used to generate User Patch Sets for use via the Export Selection and Add/Modify Points capabilities in higher license levels.
User patch sets can be generated totally from scratch, using Manual Measure to add each patch in turn, by setting the desired RGB patch value and pressing Measure, adding more patches until the desired patch set is complete.
Alternatively, any existing patch set can be use as a starting point by generating an Absolute profile as above, and then adding additional patches via Manual Measure, or combining different existing patch sets via Add/Modify Points. Any unwanted points can also be deleted as needed.
Patch Set Assessment
In combination with the Active LUT capability of ColourSpace, the Virtual Probe can be used to test and evaluate different profiling patch sets to see what difference they make.
Using any large Characterisation patch set make a profile from the display in native/uncalibrated mode and make a calibration LUT. The larger the patch set the more faithful to the actual characteristics of the display the profile will be, However, as you are really only interested in assessing the relative difference different patch sets make to profiling, being accurate to the underlying displays is actually irrelevant. However, a true volumetric patch set will be needed vs. a Quick Profile, as some non-linear characteristic will be of benefit.
Once you have a good reference profile, it can be used to assess any patch sets.
From the profile Extract the profile's native colour space, and make a LUT using the extracted colour space and the actual profile
The LUT will mimic the display errors (either the actual errors as the displays has or inverted depending on the Source/Destination selections).
The LUT can then be used as a Active LUT and the Virtual Probe used to test different patch sets through it, using the extracted colour space as the target in both Settings and in the Virtual Probe.
Evaluation can be from the profiles themselves but more importantly via generating LUTs from each different Patch set Profile and comparing the LUTs.
It is the variation in the LUTs that shows the difference each different patch set makes to the end calibration.
This approach obviously only test the patch set patch differences not the sorting/ordering of the patches, as there are no heat/thermal issues with the Virtual Probe.
In a similar way, the Virtual Probe can be used for assessment and testing of User Defined, Reduced Gamut, and Focused patch sets, etc., enabling verification that the correct gamut and luma ranges are covered.
