How to achieve ultra-high contrast? The core technology of projection revealed

Contrast ratio is one of the important indicators to measure the performance of display products. In the past two years, contrast ratio has also become a selling point for many cinema projectors . From the 100,000:1 proposed by the first LED 1080p projector last year to 200,000:1, the contrast ratio has been constantly updated. The numbers are getting bigger and bigger. What can these changes in numbers bring to users?

What is Contrast?

Contrast is the ratio of black to white in the image, that is, the gradient from black to white. The larger the ratio, the more gradient levels from black to white, the richer the color performance, and the more realistic and gorgeous the projected image. On the contrary, the smaller the contrast, the insufficient number of colors in the image, and the image will appear gray and unclear. Levels and contrast are both important components of image quality, but contrast is relatively easier to quantify and has an important impact on levels, so in less rigorous cases, we believe that higher contrast can also provide better levels.

There are currently two contrast test methods in the projector industry. One is the full-on/full-off contrast test method, which tests the brightness ratio of the full white screen to the full black screen output by the projector. The other is the ANSI contrast, which uses the ANSI standard test method to test the contrast. The ANSI contrast test method uses 16 black and white color blocks. The ratio between the average brightness of 8 white areas and the average brightness of 8 black areas is the ANSI contrast. It is precisely because of the existence of these two different measurement methods that the contrast values ​​of different brands vary greatly.

How to achieve ultra-high contrast?

As mentioned above, the higher the contrast, the richer the number of colors, and accordingly, the more realistic and natural the color expression of the projector. Therefore, the contrast parameter is particularly important in cinema projectors that target individual home users. It is no exaggeration to say that contrast is the core parameter of home projectors. So, how is the ultra-high contrast of hundreds of thousands to 1 achieved? Today, we have selected three types of projector brands that use different technologies to achieve ultra-high contrast to reveal the secret of ultra-high contrast.

LED projection How to achieve 100,000:1?

The world's first LED 1080p projector, the Luxeon H9080FD, is the first product to exceed 100,000:1 in contrast. Let us first introduce the technology used in this product to improve the contrast.

Professional-grade decoding chip Gennum VXP GF9450

Professional-grade Gennum VXP GF9450 decoding chip

The role of decoding chips in display products is very important, similar to the graphics card in desktop computers. The top video decoding chip Gennum VXP GF9450 decoding chip has multiple top video analysis and optimization technologies such as mosquito noise elimination, picture-in-picture function, 3D noise reduction, detail enhancement, adaptive edge progressive scanning, etc. How do these technologies improve image quality?

Detail Enhancement

By using the professional-grade Gennum VXP GF9450 decoding chip, the details of the picture can be enhanced. As shown in the figure above, the enhancement function can reproduce some details that cannot be displayed and improve the clarity of the projected picture.

Adaptive color automatic brightness contrast enhancement technology

As shown in the figure above, when projecting a dark scene, the adaptive color automatic brightness contrast enhancement technology can automatically adjust the brightness and contrast according to the characteristics of the picture to display more picture details. In particular, the details of the dark scene can be expressed more richly.

100,000:1 projection effect real shot

Color reproduction and texture

100,000:1 effect

3000:1 effect

Effect analysis:

As shown in the above picture, the professional-grade video decoding chip and automatic aperture technology bring a 100,000:1 ultra-high contrast ratio to reproduce the real texture details. The tender flesh color of sushi and the skin color of human face are very real and natural. Compared with a 1080p projector with a nominal 3000:1, the 100,000:1 effect is more real and natural in color reproduction, and the details are more delicate and clear.

The highest in the industry - 200,000:1

New automatic aperture system

Next, we will introduce in detail the Epson EH-TW4500, which currently has the industry's highest 200,000:1 dynamic contrast ratio.

Dynamic Aperture Technology

Dynamic aperture technology is currently widely used in mid-to-high-end projectors to improve the expressiveness of dynamic images. Since the transition between light and dark in dynamic images is relatively fast, the higher the contrast, the easier it is for the human eye to distinguish such a transition process. A projector equipped with dynamic aperture technology can make fine adjustments for each different image to control the brightness of the image, thereby projecting a clear and bright picture.

New automatic aperture system

Compared with the previous generation of products, the new product adopts a new double-layer automatic aperture system. With the real-time change of the aperture, the brightness reduction rate is reduced, the brightness change is smoother, and more layers are provided. At the same time, the black performance is also enhanced, closer to natural black.

Super resolution

To improve the color performance of the picture, Epson TW4500 has added single-frame super resolution technology.

Single frame super resolution technology

Ordinary image analysis technology is prone to losing edge details during the calculation process, resulting in an uneven picture. However, single-frame super-resolution technology can make the edge details of each frame sharper and clearer. Combined with dynamic aperture technology, it can achieve a picture effect with rich colors and clear details.

200,000:1 projection effect real shot

Skin tone restoration, texture details

Three primary colors reproduction

Effect analysis: As shown in the above picture, the character's skin color is rich and the texture is clear. The three primary colors of the fallen leaves are restored to be real and natural, and the transparency of the clear lake water is clearly visible.

Highest true contrast

The ultra-high contrast ratios of the two products we introduced above are mainly based on dynamic aperture technology. In this page, we will start from the technical principles of projectors and introduce the core technology of products with the highest true contrast ratio. The one with the highest true contrast ratio is the JVC HD990, which is a projector based on LCoS technology.

JVC Wire Grid Technology

JVC Wire Grid Technology

The difference between native contrast and dynamic contrast

Different from the dynamic aperture technology of other projectors, JVC HD990 uses a fixed aperture to eliminate excess light that may affect the contrast. In short, JVC HD990 enhances the brightness performance (extending the white peak) and a deeper and richer black level effect (expanding the black level dynamic range), making the picture more layered and deep. Thus achieving an ultra-high native contrast ratio of 70000:1.

Projection effect real shot

Terminator 4

Effect analysis: As shown in the clip of "Crouching Tiger, Hidden Dragon" above, in a completely dark scene, the faint moonlight projected on the tiles reflects the light and truly restores the details of the roof. Another example is the complex lighting scene in "Terminator 4", including the light directly hitting the character's face and the details of the clothing in the shadows are all realistically reproduced. The colorful "Phantom of the Opera" has a good performance in both bright red and dazzling metallic colors.

General Overview:

For users, the contrast of cinema projectors is a key factor affecting the image quality of projectors. This article introduces in detail the core technologies of the three cinema projectors with the highest contrast in the current market. Although the projection technologies of the three products are different (Luxon H9080FD uses DLP technology, Epson TW4500 uses 3 LCD technology, and JVC HD990 uses LCoS technology), they all achieve ultra-high contrast through different technologies, bringing real and delicate projection images. From the actual pictures above, we can see the real effect brought by the high contrast value.