Copyright permission granted for display of the SMPTE Test Pattern Rev. 10/ 6/83 by the Society of
Motion Picture and Television Engineers and for the CIE 1931 Chromaticity Diagram by Joe Kane
Productions, Inc.
Trademarks, service marks, and other registered names are hereby acknowledged to be the property of
their owners: Adobe Systems, Incorporated; Appian Graphics; Astro Design, Inc.; BARCO, Inc.;
Dicom; DOME Imaging Systems, Inc.; Intel Corporation; Matrox Electronic Systems, LTD; Microsoft
Corporation; National Display Systems; National Electrical Manufacturers Association; NEC; Sequel
Imaging Corporation; and Tektronix, Inc.
Companies and organizations should be contacted for complete information regarding trademarks and
other registrations.
VeriLUM is compliant with year 2000 standards and will not be affected by dates occurring before,
during, or after the year 2000.
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Table of Contents
Preface
1.0 Getting Started
1.1 System Requirements
1.2 Installing VeriLUM
1.3 Running VeriLUM
1.4 Uninstalling VeriLUM
2.0 Operating VeriLUM
2.1 Using VeriLUM for Acceptance Testing
2.2 Using VeriLUM for Calibration to a Luminance Response Model
2.3 Using VeriLUM for Verification and Tracking
2.4 Color Adjustments
2.5 Plot Results
3.0 Technical Notes
3.1 White Level and Black Level Settings
3.2 Selecting Luminance Measuring Device
3.3 Number of Luminance Measurements
3.4 Data File Format for User Defined Luminance Response Model
3.5 Registry Entries and Downloadable Gamma Ramps
3.6 CIE Chromaticity Coordinates
3.7 Color Temperature
3.8 Using VeriLUM with Multiple Color Monitors on a Desktop
4.0 Calibration Scenarios
4.1 One or More Grayscale Video Displays and BARCO or DOME Video Card
4.2 Windows 95/98/NT/2000 and Color Monitor and Downloadable Gamma Ramp Video
Card
4.3 Windows 95/98/NT/2000 and Color Monitor and Non-Downloadable Gamma Ramp
Video Card
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Preface
VeriLUM® 4.3 is a tool for ensuring consistent color and grayscale video display performance. In the past
this function has been the province of the video card vendors and the video monitor manufacturers. More
recently the responsibility for assuring the quality of soft copy display has been placed exactly where hard copy
quality assurance resides: in the hands of the end user. This means the end user must be able to make
reproducible measurements of the video display performance and interpret and act on the results.
Our goal is to make it easy and efficient to judge when a video display system is continuing to function
normally or needs adjustment or replacement.
One use of VeriLUM is acceptance testing of a video display system prior to signing off on procurement
paperwork.
VeriLUM also provides a quick visual check for the user. A SMPTE test pattern and a VeriLUM test pattern
can be displayed on each video monitor that is part of the desktop. If the grayscale range and stability is
adequate for each monitor, if the geometry and focus are acceptable, and if all of the monitors have essentially
the same look-and-feel, then the video system is ready for use. If one or more of the video displays is in need of
adjustment then maintenance can be requested.
For the quality assurance specialist interested in tracking consistent performance over time, a rapid set of
measurements of the display luminance is made and an index is computed for each video monitor. These
measurements take about 30 seconds per monitor and the history chart can be printed when hardcopy
documentation is required. The computed index indicates how well the video system matches a specific
luminance response model. Even if the “natural gamma” of the monitor is used, it is still possible to track the
computed index, the white level, and the black level, over time.
In addition, for color monitors, the correlated color temperature and chromaticity coordinates of the white level
and the luminance values for the red, green, and blue primaries are tracked.
VeriLUM also can be used to perform gamma correction in conformance with the DICOM® Part 14
Grayscale Standard Display Function or a user specified gamma model or any other user defined luminance
response model. Loading a lookup table at system startup time is possible if a grayscale video board is used
that has the facility for on-board gamma correction. Currently VeriLUM provides on-board gamma correction
using BARCO, DOME, Appian, and Astro grayscale video boards. If the operating system is Microsoft
Windows 95 or 98 or 2000 and if the color video card supports downloadable gamma ramps then VeriLUM will
use that capability, and download the gamma ramp onto the video card automatically. If the operating system is
Windows NT, then a few video cards support downloadable gamma ramps using non-standard driver calls (e.g.,
Matrox G200/G400/G450 and Appian Jeronimo 2000).
For color monitors two techniques are provided for adjusting the color presentation. If the operating system
and video card support downloadable gamma ramps, then VeriLUM can automatically adjust the red, green,
and blue (RGB) relative gains in order to achieve a user specified color temperature. However, even if
downloadable gamma ramps are not supported, guidance is provided about the appropriate RGB luminance
levels needed in order to achieve a desired luminance level and color temperature.
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A VeriLUM luminance pod must be connected to the PC each time the software is run. There are two different
VeriLUM pods: color and grayscale. The same software package works with either pod type. A grayscale pod
must be used with grayscale monitors. The grayscale pod can be used on color monitors, but the chomaticity
measurement features will not be available. The color pod provides chromaticity and luminance measurements
on color monitors.
Please note that, unlike most PC software packages, VeriLUM software can be installed on as many
workstations as desired; no additional licenses are required. This allows a VeriLUM pod to be taken from
workstation to workstation to perform measurements. The VeriLUM pod uses a serial communications port on
the PC and thus a simple extension cable from the serial port to the front of the PC minimizes the aggravation of
hunting around behind the PC for the proper connector.
In summary, VeriLUM provides a simple, effective tool for performing calibration, tracking, acceptance testing,
and visual verification of a color or grayscale video display system.
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1.0 Getting Started
1.1 System Requirements
VeriLUM requires an Intel PC; Microsoft Windows 95, 98, NT 4.0, or 2000 Operating System;
and a video card capable of at least 800 X 600 pixels with a minimum of 256 colors (24 bit or 32
bit true color is highly recommended) or a grayscale video board (BARCO, DOME, Appian, or
Astro). Administrator privileges are required to install VeriLUM software in Windows NT 4.0
and Windows 2000.
1.2 Installing VeriLUM
VeriLUM software is shipped on a CD-ROM. Place it in the CD reader, double-click the CD
drive icon, and double-click the VeriLUM43_Install.exe icon with the left mouse button. The
installation script will verify the minimum system requirements, create the necessary folders and
icons, and install the program files and ancillary files.
The install process uses the Microsoft Installer Technology. If the Installer Engine is not already
on the PC, it will be included in the install process and it may be necessary to restart the PC
during and/or after the install procedure.
This User Guide is included on the CD in both Microsoft Word format and in Adobe Acrobat
PDF format. Please print as many copies as you need. In addition, this User Guide is copied to
the folder in which VeriLUM is installed so it is available on each PC where VeriLUM is used.
1.3 Running VeriLUM
[ Note: With one exception, VeriLUM uses the left mouse button exclusively. Thus all references
to clicking imply left mouse button clicks. The exception is a right mouse click to toggle the
gamma correction on and off in VeriDisplay (see Section 2.2). ]
Connect a VeriLUM pod (color or grayscale) to an active COM port on the PC. Auto-detection
of the COM ports is performed. Click on Start / Programs / VeriLUM and then click on the
VeriLUM icon.
Normally the VeriLUM main dialog box appears as shown in Figure 1
However, the first time VeriLUM is run, a configuration dialog box appears (see Figure 2).
Please specify the number of video monitors comprising the desktop. This ensures that the video
measurements are made in the center of each monitor and not the center of the desktop. Click
the OK button to activate the main dialog box of VeriLUM.
The EXIT button returns control to the desktop.
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The Configuration dialog box has two buttons in the upper right-hand corner that we use to select
the type of VeriLUM pod being used (Grayscale or Color) and the display device being used.
See Figures 2A and 2B.
The default selections are to set up VeriLUM to run with a grayscale pod and on a CRT.
If you have a National Display Systems Nova Series LCD flat panel display running on a Matrox
G200 MMS video card, then click that button. The other choices are for a National Display
Systems Vector Series LCD flat panel and a NEC 1830 LCD flat panel.
Other flat panel vendors and models will be added in the future.
A percent surround value can also be specified. Once specified, this value is used for all
luminance measurements, in particular all luminance measurements for determining the DICOM
Part 14 gamma correction table. The default value is 20%.
All other buttons are described in Section 2, Operating VeriLUM .
When using VeriLUM with a color monitor and an operating system and video card that permits
downloading gamma ramps, a Task Bar Status Area Icon appears. Resting the mouse pointer on
the icon activates the message “Gamma Correction On Off.” Clicking on the icon initiates a
dialogue to toggle the gamma correction lookup table on the video card between gamma
correction and no gamma correction. This allows a user to choose to view color images without
gamma correction of the gray scale and then to choose to view grayscale images with the gamma
correction turned on.
1.4 Uninstalling VeriLUM
An icon for removing VeriLUM is in the Control Panel under the Add/Remove Programs
function. If you click the VeriLUM item in the program list, you will be asked whether you are
certain you want to remove the VeriLUM application. If you answer YESthen all files and icons
created as a part of the install process will be removed. Files created during the operation of the
VeriLUM software will not be removed.