LED HD LCD display all kinds of color processing technique

AddTime:11/22/2016 12:50:47 AM
 LED HD screen while a monochromatic light colored, but LED still has about 30~50nm of the half wave width, so the color saturation is limited. A riot of colours of nature is so beautiful, unfortunately LED display current cannot be completely reproduced this beautiful scenery.

A, white field color coordinate adjustment:

White field chromaticity coordinate distribution is one of the basic techniques for full color LED display screen. But in twentieth Century 90 time metaphase, due to the lack of industry standards and test methods, usually by the human eye, feel sure white color coordinates, resulting in serious color and white color temperature optional. Along with the development of industry standards and testing means complete, many manufacturers began to regulate the full color matching technology. But there are still some manufacturers because of the lack of theoretical guidance of color, gray level, often at the expense of some color to the deployment of hundreds of color coordinates, the comprehensive performance is not improved.

In summary, we mainly discuss three aspects of the problem:

1, how to improve the LED HD display chroma uniformity;

2, how to expand the gamut, restore more natural color;

3, how to improve the LED display color reduction degree;

Industry has a very wide range of applications, the LED has a wavelength in different application of different requirements, the choice of some LED wavelength is in order to get a good visual effect, some are in order to meet the people's habits, and some are industry standards, national standards and requirements of international standard.

The chroma process technology in the specific implementation, are related to each other, some even can not have both fish and bear's paw. Integrated LED display is also necessary for the luminance uniformity correction, gray linear transformation, image enhancement, noise reduction, dynamic pixel processing, the signal processing flow is very complex. Therefore, we must weigh the performance from the point of view of system, a good grasp of the processing order, and increase the signal processing depth, in order to make the full color LED display screen to show a colorful world of a riot of colours.

For example, in full color LED display screen in tube wavelength selection; early selection of wavelength is generally 570nm LED yellow green, although the cost is relatively low, but the display color gamut is smaller, color reproduction is poor, low brightness. And in the choice of the wavelength of 525nm after the pure green tube, display color gamut expansion has nearly doubled, and the color reduction degree is greatly improved, and greatly improve the visual effect of the screen.

Two, 3+2 multi primary color processing method:

In recent years, in the field of flat display are keen to discuss the multi primary display 3+3 (red, green, blue and yellow, green, purple), to expand the gamut, more natural color reproduction. So, LED screen can display 3+3 to achieve multi colors?

We know that in the range of visible light, yellow, green for the monochromatic light, we have a high degree of saturation of yellow, cyan LED. And for polychromatic light purple, purple is the single chip of LED does not exist. Although we can not achieve the red, green, blue and yellow, green, purple color LED display 3+3. However, the research of red, green, yellow, blue and green 3+2 color LED display is feasible. As the nature of the existence of a large number of high saturation of yellow and blue; therefore, the study is of some value.

In a variety of television standards, video source only red green and blue three primary colors, yellow, green two color without. Then, the yellow, green two color display terminal how to drive?

In fact, in the determination of yellow, green two color driving strength; we follow the following three principles:

1, increase the yellow, green two colors in order to expand the gamut, so as to improve the color saturation. While the overall brightness value cannot be changed;

2, to improve the color saturation and at the same time, may not change the tone;

3, with D65 as the center; to RYGCB color gamut boundary as the endpoint, the color gamut range of each point in the linear expansion.

In the above under the guidance of three principles: according to law of gravity center, we can find the 3+2 multi primary color processing method. However, in order to realize the 3+2 multi primary color, we have to overcome the yellow, cyan LED brightness; difficulties such as rising costs, is currently limited to theoretical discussion.

Three, the chroma uniformity processing:

Full color LED display chroma uniformity has been a difficult problem in the industry generally believe that LED, the uneven brightness can be a single point correction, to improve the uniformity of brightness. The uneven color is not correct, only through the subdivision and screening of the LED color coordinate to improve.

Four, color reduction treatment:

The birth of pure blue, pure green LED, so that the full color LED display screen with the color gamut range wide, high brightness by the industry sought. However, the chromaticity coordinates of the red green blue LED chromaticity coordinates and PAL TV RGB of a large deviation (see Table 1), the LED full color display color reproduction. Especially in the representation of the color, the deviation is more obvious visual. Thus, emerge as the times require color processing technology. Methods the author recommend two kinds of color reduction treatment:

1, only the most sensitive to the human skin color gamut for proper correction; and is not sensitive to the other eye color gamut as little as possible to reduce the original color saturation. So, in the color restore balance between degree and color saturation.

2, the red green and blue three primary colors LED color coordinate transform, the three primary colors chromaticity coordinates between the LED and the PAL television both as close as possible, so as to improve the LED display color reduction degree. However, this method greatly reduced the LED display color