Pixels out of control rate
Pixels out of control rate refers to the smallest screen imaging units (pixels) does not work correctly (control) proportion. The pixel control has two modes: one blind spot, that is, blind spots, in the time it does not need bright light, called blind spots; second, often highlight the need but does not shine when it has been lit, called the regular highlights. In general, the composition of pixels have 2R1G1B (2 red light, a green and a blue light, following the same reason), 1R1G1B, 2R1G, 3R6G so out of control is generally not the same pixel in the red, green, and blue light while all the out of control, in which a lamp out of control as long as we believe that this pixel is out of control. For simplicity, we have by the color LED display (red, green, blue) pixels respectively out of control statistics and calculations, whichever is the maximum out of control as the pixel display rate.
The number of pixels out of control accounted for the total number of full-screen pixel ratio, which we call "full-screen pixel out of control rate." Moreover, to avoid loss of control of any one pixel region, we proposed "regional pixels out of control rate", that is, 100 × 100 pixels in the region, out of control the number of pixels and the total pixel area (ie 10,000) of the same. The index of the "LED display general specification" SJ/T11141-2003 in "out of control pixels were discrete distribution" requirements were quantified, convenient and intuitive.
Currently the LED display in the factory will be aging (roast machine), LED lights on the control pixels are maintained or changed, "the entire screen pixels out of control rate" control in 1 / 104 s, the "regional pixels out of control rate" control 3 / 104 is not within the issues, or even some individual manufacturers of enterprise standards before leaving the factory is not allowed out of control pixels, but this is bound to increase the manufacturer's manufacturing and maintenance costs and extend the delivery time. In different applications, the pixel control the rate of actual requirements can have great differences, in general, LED display for video playback, the indicator control in 1 / 104 is acceptable within, is to be achieved; If the characters for simple information dissemination, the indicator control is reasonable within 12/104
Gray is the so-called color scale or gray scale, is the degree of brightness of light and shade. The digital display technology, the gray is the determinant of the number of display colors. Generally speaking, the higher the gray, richer color display screen and the more delicate, more performance rich in detail.
Gray level depends on the system's A / D converter bits. Of course the system of video processing chips, memory and the transmission system must provide the appropriate support Caixing median. Currently the main uses 8-bit LED display processing system, namely 256 (28) gray scales. Simple to understand that from a total of 256 black to white brightness variations. Using RGB primary colors constitute a 256 × 256 × 256 = 16777216 colors. Known as 16 trillion colors. Major international brands with 10-bit display processing system, that is 1024 gray scale, RGB color RGB constitute 1.07 billion.
Although the number of gray color determinants of the decision, but the bigger the better is not to say unlimited. Because the first resolution of the human eye is limited, Moreover the system will involve dealing with the improvement of the median to the system video processing, storage, transmission, scanning and other links of change, the cost of sharp increases in cost reduction rather than. General civil or commercial grade products can be 8-bit systems, broadcast-level products in a 10-bit systems.
Brightness level is the identification of the human eye to distinguish the image from the black to the brightness level between the most white. Mentioned earlier, the gray scale of some very high, can reach 256 or even 1024. However, due to the sensitivity of brightness the human eye is limited, and can not identify these gray levels. That is probably many neighboring gray level is the same as the human eye looks. And the resolving power of each eye varies. For the display, identify the level of the human eye is naturally the more the better, because the displayed image, after all, be looked at. The human eye can distinguish brightness levels more space means higher color display to show the greater potential of rich colors. Brightness level can identify specific software to test, generally up to 20 screens can be more than even a good grade.
Gray is the gray nonlinear transformation of data in accordance with the empirical data or a non-linear relationship between the arithmetic transform be provided to screen display. As the LED is a linear device, with the traditional display of non-linear display characteristics different. In order to make LED display can meet the traditional data sources without loss of gray level, usually in the LED display system will do after the gray-level data, the nonlinear transformation, the transformed data the median increase (to ensure no loss of gray degree of data). Internal control systems are now a number of suppliers so-called gray or 16 384 4096 or later are gray through nonlinear transformation that gray space. 4096 is the use of the 8-bit source to 12-bit nonlinear transform space, 16,384 are from 8 to 16 using the nonlinear transform. By the 8-bit source as nonlinear transformation, the transformed space is certainly higher than 8-bit source large. Usually at least 10. As gray as this parameter is not bigger is better, generally 12 to do enough to change the. I am a professional writer from China Quality Digital, which contains a great deal of information about pos receipt printers , thermal paper printers, welcome to visit!
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