How to Use Sensor Matrix Corrections in HCFR and in JVC Autocal (CCMX)

The below article contains excerpts from The Display Calibration Guide and the JVC Autocal Guide.

You can create your own meter corrections (called CCMX files) by profiling a meter to a more accurate spectrometer. This is normally helpful if there is concern that the colorimeter has drifted from its factory default state or you want to get more accuracy for the particular display you are profiling.

Matrix Corrections are 6 numbers (3 for each axis x, y, z) that describe the drift difference for the colours between a good known sensor (usually a spectrometer) and the sensor you want to use.

You can build Matrix Corrections with both HCFR and with ArgyllCMS command line tool. However, it is important that matrix corrections ARE NOT built ON TOP OF spectral samples, however. These are the options that show up when you select a Display Type on the Argyll / HCFR Sensor Selection page.

The display type you should select when building a matrix correction is either Refresh or Non-Refresh Display, to get the colorimeter to return the raw data without a Spectral Sample (CCSS or EDR) being loaded.

Creating CCMX in HCFR

To create a CCMX in HCFR, you will need to start TWO projects, one with your reference instrument (preferably and spectrometer), and a target instrument that you will be making the corrections for.

Both instruments should be pointed at the same part of the display panel without blocking each other’s view or seeing each other’s shadow.

In HCFR, you will need to mark the project that you opened with your reference meter as “reference”. There is a tick box on both the right bottom of the screen as well as the right top.

Switch back to the project with you target instrument. You should leave this box unticked for your target instrument.

Now go to the menu and select Advanced –> Meter Correction File –> Build using simultaneous measures to build the correction. You have some other options here that you can also explore.

Creating CCMX in ArgyllCMS

To install ArgyllCMS, refer to this article.

You can find the documentation for ccxxmake.exe here: https://www.argyllcms.com/doc/ccxxmake.html. You will need to have both a reference meter and the colorimeter / target meter plugged in before executing the command with the correct flags.

Using CCMX in HCFR

You can load the correction file from the Advanced Menu as below.

A matrix correction can also be entered into the second tab as you initialise the sensor (the tab is called Sensor Matrix). Please see the picture below. This dialogue can also be opened from the Advanced menu –> Manually edit XYZ matrix as shown above.

Using CCMX in AutoCal

AutoCal creates a file named “init.xml” in the “AppData directory”.
For example, for version 13, it is “C:Users\YourName\AppData\Roaming\JVCKENWOOD\Proje ctor Calibration Software 13”.

The AppData directory is hidden so you have to enable hidden files in Windows folder options to be able to see it.

In the init.xlm file there is a section called matrixOfSensor as below:

<matrixOfSensor>

<double>1</double>

<double>0</double>

<double>0</double>

<double>0</double>

<double>1</double>

<double>0</double>

<double>0</double>

<double>0</double>

<double>1</double>

</matrixOfSensor>

This corresponds to the matrix.:

1, 0, 0,

0, 1, 0

0, 0, 1

Here you can enter the values for a 3 x 3 correction matrix, which you have determined in HCFR or other compatible software.

For example, you enter the following: 

<matrixOfSensor>

<double>0.962</double> <double>0.00485</double> <double>0.00425338</double>

<double>0.051885</double> <double>0.98522</double> <double>0.002102</double>

<double>-0.002255</double> <double>0.003445</double> <double>0.92885</double>

</matrixOfSensor>

Pro Guides

The Display Calibration Guide

JVC Autocal Guide