Monitor testing methodology
On the pages of our website we are trying to present you the latest developments in computer components market. But due to lack of proper equipment one of the components was omitted, although this element is very important either for office or game purpose. As you may guess we are talking about monitors.
Monitor market develops along with other components: new technologies and improved capabilities are continuously introduced. Therefore the relevance of these devices reviews has not doubts.
During testing methodology preparation we focused on the following monitor parameters: color rendering accuracy, uniformity of screen illumination and color temperature, contrast dependence on intensity level, matrix rate and viewing angles. Another parameter of rating is device calibration capability and type of end product after testing.
We plan to provide the testing on the basis of mini-computer ZOTAC ZBOX NANO ID65-PLUS-BE. Since the level of components does not affect the result of the test, there is no need to pay much attention to these products. But the device for note reading should be considered in more details.
For experimental procedure we use X-Rite i1Display Pro calibrator. Thanks to its accurate and rapid operation it is perfect for our purposes. In addition, it can be used not only for monitor measurement and adjustment but also for other screening devices such as TV sets, Plasma Display Panels, projection devices, phones, etc.
Together with calibrator functional utility program X-Rite i1Profiler is provided. It has a good account during calibration of the monitor. However to cover the full range of planned tests its capacity is not enough. Therefore, in the course of the experiments a number of various utility programs will be used. Full list of software used during testing is given below.
Argyll CMS with graphical interface DispcalGUI
Pixel Persistence Analyzer
Let us note that all utilities are free of charge and support a great number of calibrators including present device.
After briefly presentation of testing tools, we offer to consider its stages. At first we examine the characteristics of preset monitor profiles. Then we choose the most suitable for accurate color rendering. Then we standardize the monitor and analyze the obtained results.
Accuracy of hue rendering
The essence of this experiment is to determine the correctness of monitor to render the hue as well as to estimate the maximum and the mean error. To check this parameter we use 51-color palette. After testing we obtain a report, where the main indices are the last two columns. These columns represent the deviation from the desired hue
A good result is if the deviation (dE*94) from each color (ΔH) does not exceed 3, and mean delta (ΔE) is 1. Permissible values are 4 and 1.5 respectively. If obtained data exceed these values we can talk about the wrong color rendering. The value and color nominal allow to judge about places of hue deviations.
Color gamut allows us to estimate how many colors available for the human eye perception can render the monitor. In other words how the colors will be “clean” and natural. Numerically, this is a percentage of the real color range to a standard color space. Currently the most popular color spaces are sRGB and AdobeRGB. The first is used in games, movies and amateur photography. The second one is more professional and used in printing industry. In the first place we will focus to sRGB gamut correspondence. But if the monitor is pretend to professional status the special attention will be paid to both color spaces.
The result is considered as good if sRGB value is 90% and AdobeRGB more than 65%. If we are talking about professional devices the gamut should be 100%.
For a better perception the results will be presented in the type of CIE-diagrams where gray dotted line indentifies the limit of standard color space (sRGB or AdobeRGB), and firm line specifies the obtained range.