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Extron Scalers & Scan Converters from AV Supply Extron manufactures computer-video interfaces, switchers, distribution amplifiers, computer-video scan converters, scalers, signal processing equipment, and high resolution cables. These products are used to integrate computer, video, and audio into presentation displays for today's boardrooms, presentation/training centers, university lecture halls, and other applications. Give us a call at 1-800-284-2288 or email us to have one of our knowledgeable sales representatives help you to interface to an Extron system that will suit your needs. Audio Video Supply interfaces to all your new or used Extron products. We can help you design your system so give us a call today at 1-800-284-2288 or email us.

Call 1-800-284-2288 or email us about Extron Scalers & Scan Converters!

A scaler is an electronic device that converts a video or computer-video signal of one resolution to another, typically higher resolution. In general use, a video scaler is used to convert composite video, S-video, or component video and, in some cases, RGB computer-video signals, to a computer-video resolution that matches the native resolution of a plasma or LCD monitor, or data projector.

Scan converters, on the other hand, do just the opposite: they convert a high resolution computer-video signal to match the low resolution needs of NTSC or PAL video, so that the computer image can be viewed on a television or recorded on a VCR or DVD.

Scalers:

Now that we have our frame of reference, we can now make decisions as to how to display video images of one resolution on a projector or monitor of a different resolution. To display standard definition NTSC or PAL video on a computer monitor or data projector, it is typically necessary to scale the video image up to a higher pixel count in both the horizontal and vertical dimensions. For example, an NTSC resolution signal of 720x486 pixels must be increased to match the resolution of a common data projector resolution such as 1024x768. This increase in horizontal and vertical pixels is accomplished using a video scaler. In essence, a scaler takes a standard definition video signal and converts it to what we commonly refer to as ''computer-video.''

Let's take a quick look at how video scalers work. On the input side, the scaler incorporates a decoder that converts the complex NTSC and PAL video signals into the three primary colors of light, red, green, and blue, that are required by the projector or monitor. Video scalers are typically adjustable to accommodate a variety of output resolutions to match the variety of resolutions found on display devices. It's important to match the output of the scaler to the native resolution of the display in order to realize the highest image quality and to utilize the maximum available image area on the display. For example, matching a scaler output of 1024x768 pixels to a display of the same resolution yields the optimal results. Matching a scaler output of 800x600 pixels to a display with a resolution of 1024x768 pixels yields less desirable results; the image may be smaller than the available screen area, or the display itself may scale the incoming signal again, adding artifacts and potentially degrading image quality. Since virtually all computer monitors and projectors have native resolutions that far exceed that of television-grade images, video scaling has become a desirable solution for adjusting the resolution of the video image to conform to these higher resolution displays.

Image scaling is not limited just to the matching of video signals to computer-video resolutions. Standard definition, analog NTSC and PAL television standards are being replaced by new, high definition digital television systems. In the United States, the ATSC or Advanced Television Systems Committee has defined as many as 18 different television transmission standards, with two primary resolution structures: 1280x720 pixels and 1920x1080 pixels. Each of these can be transmitted at a variety of refresh or frame rates. In Europe, countries are adopting similar standards called DVB or Digital Video Broadcast, for both terrestrial and satellite transmission. High definition television may be transmitted as a progressive scan signal, where full frames of video are transmitted sequentially, or as an interlaced signal where alternating fields of odd and even lines are transmitted sequentially. Regardless of the resolution structure and frame rate of the high definition image, the pixel resolution is more compatible with computer-video display products, although the HDTV aspect ratio of 16 units wide by 9 units tall, or 1.78:1, may differ from the common computer display aspect ratio of 4 units wide by 3 units tall, or 1.33:1. Managing these various scan rates and aspect ratios is most easily accomplished with a video scaler.

Advantages of an Image Scaler:

Perhaps the most important, key attribute of a video scaler is the way in which it can simplify the design of an A/V system. When video signals are scaled up to match the native resolution of the display, the system requires only one RGBHV connection to the display. This reduces installation time and cabling, and minimizes control system programming as well. Other advantages include:

• Fewer points of failure

• Allows the use of smaller conduit

• Simplifies operation and control

• Speeds operation by eliminating the need for the projector to switch between inputs

• Key Features of an Image Scaler:

• Image sizing and aspect ratio control

• Pre-programmed, common resolutions native to typical display devices

• Input rate auto-scanning

• Memory presets

• Remote control via IP Link® and/or RS-232

Scan Converters:

To this point, we've concentrated on the conversion of television-quality images up to computer-video resolutions. On the flip side, there are just as many occasions in which computer resolution images must be converted for use in a television or video presentation application. For example, computer graphics such as those used in PowerPoint® presentations must be converted to a video signal in order to be transmitted over a videoconference system, or recorded on a DVD. In cases such as these, the resolution of the image is higher than the capability of the system that will convey the image to the viewer. To make the conversion from a higher resolution image to a lower resolution, we typically use a reverse scaler, or scan converter.

The scan converter is an image scaler that's specially designed to decrease, or conform, computer-video image resolution to match that of a lower resolution system such as NTSC or PAL video, or to that of MPEG-2 data for Internet streaming applications. The scan conversion process is complicated by the fact that some information in the original image may be lost in the down-conversion process. For example, if the original image has a resolution of 1024x768 pixels and it is being converted to 720x486 pixels for NTSC video, it will be necessary to compress or eliminate 304 pixels on the horizontal plane, and 282 pixels on the vertical plane. Deciding which image information is redundant, and which is important, requires a significant amount of signal processing. Most scan converters include specialized, adjustable image filters that can be used to minimize the loss of detail and provide the best possible image when the original is compressed.

Scan Converter Attributes to Consider: 

• Compatibility with the computer's maximum output resolution

• Ability to genlock two or more input signals

• Quantizing level, or width of data bit path used to process image information

• Quality of the broadcast or MPEG-2 encoder

• The necessary output video formats required for use

• Support for digital input and output formats such as SDI and HD-SDI

• Need for a test pattern generator

• Ability to manage product updates via software downloads and field-upgradeable hardware

Various Types Available:

Video Scalers: Extron Video Scalers are commonly used to scale standard definition video signals, such as component video, S-video, and composite video, to high resolution output rates, including HDTV. Many of the scalers in this category also offer input switching, aspect ratio conversion, and quad standard video decoding for worldwide compatibility.

RGB Scalers: Extron RGB Scalers accept RGB/computer-video high resolution sources and scale them to another RGB/computer-video resolution — or HDTV or plasma/LCD resolution depending on the scaler. They also include additional capabilities, such as picture controls for brightness and contrast.

Video & RGB Scalers: Extron Video & RGB Scalers are capable of scaling RGB, component video, S-video, composite video, and/or optional SDI - Serial Digital Interface video formats up or down into a single output resolution — while maintaining optimum image quality. These scalers offer multiple scaled output rates, including computer-video, plasma or LCD, and HDTV rates.

Seamless Switchers: Extron Seamless Switchers provide high performance scaling of standard definition video, HDTV, and computer-video sources to high resolution output rates, including HDTV. They also offer true seamless switching between inputs with selectable transition effects for professional quality presentations.

Scan Converters: Extron Scan Converters optimize high resolution computer-video signals for use on standard definition video displays. Each scan converter Extron manufactures provides a different set of features and level of functionality.

Scaling Matrix Switchers: Extron Scaling matrix switchers are designed for applications requiring all video input signals to be scaled to a common video output rate. They support high resolution, up to 1400x1050, as well as HDTV video signals.

Universal Signal Processors: An Extron Universal Signal Processor combines high performance scaling, switching, scan conversion, standards conversion, and transcoding in one unit. It accepts a wide range of video input signals and transcodes them, or converts them up or down, into a number of different signal formats to meet the video signal requirements of virtually any system.

Scalers & Scan Converter Accessories: Extron offers a variety of accessories for select scalers and scan converters including IR remote controls, SDI and DVI expansion boards, and remote control panels.

Call 1-800-284-2288 or email us about Extron Scalers & Scan Converters!