A text to understand the 9 major functions and technical characteristics of LED display video processor
Led video processor introduction
The LED video processor is also called a picture processor, an image converter, a video controller, an image processor picture converter, a video format converter independent video source, and the like.
LED video processor is the witness, and key equipment for the birth, growth and maturity of LED full-color display. The advantages and disadvantages of LED video processor directly affect the display effect of LED display. The binding of the LED video processor to the display screen greatly facilitates the wide application of the end user and improves the depth of use of the LED display.
Full-color LED multi-screen video image processor is a high-performance image processing and control device for full-color LEDs launched by national high-tech enterprises. The device integrates many years of experience in video image processing, high-definition signal processing and display. It adopts patented hardware design and combines the special requirements of full-color LED display to accept and process many different video graphics signals at the same time. And displayed on the full color LED.
LED video processor principle
In use, LED video processors generally need to complete the following processes:
1, resolution specification conversion: In general, the image signal source (such as Blu-ray DVD, computer, HD player box, etc.) provides a fixed resolution of the signal resolution (refer to VESA, ITU, SMPTE, etc.), and led display The modular splicing display of the screen allows the resolution to be almost any value. The video processor converts a wide variety of signal resolutions into the actual physical display resolution of the led display.
2, color space conversion: LED display color gamut is very wide, and the color space of most image signals are relatively small (such as NTSC). In order for the LED display to have an excellent image display effect, color space conversion is necessary.
3. Bit depth improvement: The gray level of the current LED display has been increased to 16 bits and 17 bits, but the input signal source is mostly only 8 bits. Therefore, following the arrival of the era of high-definition display, the application of 10-bit or even 12-bit processing technology in video processors has become an irresistible trend.
4. Zoom: During the resolution specification conversion process, the image needs to be scaled. Whether the resolution is increased or decreased, the complete image can be displayed on the screen.
5. Image Processing and Enhancement Technology: Digital image processing technology has developed from the 1920s to the present, and a large number of patented technologies have emerged. For example, DCDi, ACC2, ACM3D and other Emmy-winning Faroudja laboratories a series of patented technologies. These techniques undoubtedly make the visual effect of the image greatly improved.
LED video processor technology features
1. Support single and double screen display, support PIP/POP between any other signals except two composite signals;
2. Support cascading splicing and arbitrary cutting;
3. Support point-by-point zooming and arbitrary drag and drop (the picture can be adjusted point by point, the minimum can be reduced to one pixel);
4. Supports more than 7 channels of high definition SD video input, 2 channels of output, and can be expanded;
5. With TV function can automatically select the station, support Ethernet remote control and playback;
6. Support screen capture function, you can play any area, similar to QQ screenshot, video signal can also be cut;
7. Full ten-bit processing, realizing 1024-level grayscale of real image, and the image detail performance is very superior;
8. Support control panel independent operation, simple and convenient;
9. Support RS232 host computer for image operations such as zooming, dragging and cropping;
10. Support brightness, chromaticity, contrast, saturation adjustment, enhance image display;
11. Support multi-processor splicing of large full color screen, and have flexible scalability;
12. Support motion compensation, the screen does not appear tailing;
13. Support noise reduction processing to reduce noise and stains;
14. Support edge sharpening and enhance contours;
15. Support maximum output resolution: 1280 × 1024 or 1920 × 1080 or 1440 * 900;
16. Support keyboard lock function to prevent misoperation after construction and debugging;
17. There is synchronous audio output;
18. International 1U standard height, easy to carry.
9 major functions of LED display video processor
1, detail enhancement
The core of this technology is not only reflected in the sharpening of the edges of the image, but also includes the processing of color restoration and image scaling. The quality of this indicator of the video processor directly reflects the image clarity displayed on the LED display.
2, noise suppression (NoiseReduction)
Due to the dot-matrix characteristics of the LED display, the insignificant noise in other display media will greatly challenge the LED to show the audience's psychological tolerance. The noise mainly comes from the compression noise (mosaic) of the video signal and the random noise of the system itself. The excellent video processor can suppress the noise to the image quality itself by noise suppression.
3, gray level (GrayScale)
Gray scale has always been the goal pursued by LED display manufacturers, but most of the technical teams have been solving the gray level problem of the LED screen itself, and the gray level processing has been upgraded to the current 16bit. , 17bit. However, it ignores the problem that the input signal source has only 8 bits. The 8-bit source of the signal makes the grayscale upgrade of most people seem a bit like a castle in the air. Solving the problem of gray level processing of video processors is one of the most important key technologies to improve the overall display quality of LEDs. Combined with the advent of the current high-definition display era, the application of 10bit processing technology in video processors is the trend of the times.
4, format conversion function
The signal format of the PC camp (VESA organization) in the consumer field and the video format of the consumer or professional video (ITU and SMPTE organizations) spanned from the analog signal era to the digital signal era and even the current high-definition display in the early days of enlightenment. And many of the legacy signal formats and signal standards are still active or working in the consumer market, so in most engineering bids, video processors are needed to solve signal access, processing and display problems. The fundamental solution is that the video processing device can complete the format conversion problem between many signal formats, including the following:
The VGA~UXGA signal format conversion of the camp involves the processing of signal input interfaces VGA (analog), DVI-D (digital), HDMI (digital) and Displayport;
And the SMPTE camp's 480i ~ 1080p60 signal format conversion, digital bandwidth from 143Mbps to 3G height. It involves the processing of composite video (analog), S-terminal (analog), standard-definition component (YCbCr), high-definition component (YPbPr), SD-SDI (digital), HD-SDI (digital) of signal input interface;
The mutual conversion between formats is called upconversion (UpConvert, such as VGA to XGA conversion) or downconversion (DownConvert, such as UXGA to XGA conversion); and SMPTE to VESA format conversion is called cross transformation (CrossConvert, such as composite Video to XGA conversion);
5, color space conversion function
The color space is much larger than the NTSC color space of the TV signal. Therefore, if the RGB color space of the NTSC is used directly in the display screen to control the illumination of the three primary colors of the LED, a color deviation will occur, which seriously affects the display effect of the LED display. Therefore, the video processor is required to complete the transformation of the color space, that is, the conversion of CCIR601 and CCIR709 to the RGB color space. This is also the root cause of the conversion of VESA and ITU and SMPTE signal formats to VESA standard signal formats when the LED-specific video processor completes the format conversion function.
6, image processing and enhancement technology
Full-color large-screen display not only involves image processing technology issues involved in general image display processing, such as 3:2 and 2:2 pull-down, because the pixel pitch is much larger than other display media, so for image processing technology especially Image enhancement technology has more stringent requirements, including the following:
7. Motion compensation
It involves motion compensation for slow images and fast images. Good motion compensation technology can reduce the aliasing of the edges of moving images when LEDs are displayed;
8, deinterlace (De-interlace)
Video signals must use interlaced scanning to reduce bandwidth and increase resolution.
The interlaced signal needs to be preprocessed to the progressive line signal during display. Excellent deinterlacing technology eliminates the scanning line effects that exist during live broadcasts and shooting;
9, scaling (Scale)
The display uses a modular design, so the requirements for image and video display are higher, especially the display resolution of each engineering application can hardly be found in the VESA standard. Therefore, the video processor is required to provide zooming functionality. Typical scaling features are as follows:
The dot matrix resolution for general display engineering applications is below the VESA standard XGA (1024*768) resolution. The video processor is required to reduce the respective signals to be accessed to the resolution of the corresponding terminal, and it is preferable to require the video processing device to have a pixel-by-point pixel scaling function (pixel-by-point pixel scaling can be performed simultaneously in the horizontal and vertical directions).
More and more engineering applications, especially the amount of building advertising, and so on, the resolution of LED display is not limited to the conventional XGA resolution, and some engineering applications even reached the level of 2048 points (including pixel sharing). The scale. In similar applications, the video processor needs to have enhanced processing technology for image magnification. The key metric is that the internal processing bandwidth of the video processor can reach or exceed the dot matrix area of 2048x1536 in atypical applications. In conjunction with such applications, the video processor needs to have a stack function to complete the final dot matrix display through multiple video wall stitching.
The importance of LED video processors
LED video processor is the witness, and key equipment for the birth, growth and maturity of LED full-color display. The advantages and disadvantages of LED video processor directly affect the display effect of LED display.
The video processor is the witness, witness and the iconic device for the birth, growth and maturity of the LED full-color display. The LED-specific video processing equipment has gradually matured in the process. The advantages and disadvantages of the LED video processor directly affect the LED display. The display effect of the screen. In the HD era of LED display, the video processor not only carries a lot of work such as image processing and analysis, codec compression, but also a large number of intelligent analysis algorithms to analyze massive data. The binding of the LED video processor to the display screen greatly facilitates the wide application of the end user and improves the depth of use of the LED display.