Standalone ultra high definition 4K video combiner - EZwindow4K front view

4K UHD Video Combiner

The EZwindow4K™ UHD video combiner provides video combining for 4K displays up to 4096×2400 @ 60 Hz. Designed for applications that require combining of low latency UHD video with up to 4 additional video streams, to produce a single UHD video output with overlays and/or windows.



Supports 4K displays

Video combining for 4K displays up to 4096×2400 @ 60Hz resolution

Up to 5 input channels

(1) low latency UHD 4xSL DVI input plus (4) input board slots that may house various input boards

Video keying with blending

RGB, Luma, or HSV Keying inside user-defined key area with programmable foreground & background alphas when key is true or false.  Separate user-defined foreground and background alphas outside the key area


Video combining

Windowing, split screen, top-bottom, PIP, and more


Training and simulation environments

Combining multiple display images into a single instructor operator station (IOS) monitor feed in training and simulation environments

Combining HUD and out-the-window video

Combining HUD image with Out-the-Window video for a single projector

Educational environments

Combining multiple desktop images in educational applications

Real-time, minimal latency video combining applications

Any application that combines multiple video sources in real-time, with minimal latency and minimal video artifacts

Display Interfaces and Control

EZwindow4K inputs and outputs - back view

Input Features

Low Latency Ultra High Resolution Input
  • UHD LL Input: The standard low latency input is 4xSL DVI-D, compatible with many computer graphics cards and projectors with stripe configurations, and resolutions up to 4096×2400
  • LL Mezzanine Input: The optional low latency mezzanine input can be either DisplayPort 1.2 or HDMI 2.0
Up to 4 Additional Input Slots (1-4)

 Input Board A: Multi-Format Input Board (shown above)

  • Supports the following inputs: DVI-D, RGBHV, RGBsog, RS170, RS343, component, composite (NTSC/PAL). Any one of these inputs may be selected.  Digitization and de-interlacing of interlaced video formats, including RS170, RS343, NTSC and PAL
  • Resolutions up to WUXGA with pixel rates up to 162MHz

Output Features

  • 4 x SL DVI-D UHD output
  • Optional DP 1.2 or HDMI 2.0 mezzanine boards
  • Resolutions up to 4096×2400 @ 60Hz
  • Interlaced / non-interlaced conversion
  • Windowing / PIP
  • Image flip, scale, and rotate
  • Programmable Boarder Colors
  • Digital contrast and brightness adjustments


  • Free run, External sync, locked to hi-res input, or sync to input

Remote Interface Control

  • Remote interface for both initial setup and operational control
  • Commands define the input type and timing
  • RS-232, USB, and Ethernet with commands defined in the command line description

Video Blending with Keying

Alpha blend

Two video sources are mixed per a user defined ratio. This is the most common video blending technique.

RGB keying

Two video sources are mixed, based on RGB content of one of the video sources. Allows Up to (4) different levels of mixing based on If-Then-Else logic statements for RGB content.

HSV keying

Two video sources are mixed, based on the calculated HSV value of each RGB pixel in one of the video sources.

Independent windowing: 4K @ 60Hz

Examples (not exhaustive) of independent windowing with up to four video feeds (Windows 1-4) and a low latency 4K background channel

video windowing example with four video feeds and 4K at 60Hz

Independent windowing: 4K @ 30Hz

Examples (not exhaustive) of independent windowing with up to four video feeds (Windows 1-4) and a low latency 4K background channel

video windowing example with four video feeds and 4K at 30Hz

Powerful Configuration Utility

Use Westar’s EZwindow4K configuration utility to define the input timing, output timing, keying scheme, and the area-of-interest within the source video and where to map the AOI within the output resolution. The configuration utility supports user-defined:

  • Input Timing and Output Timing
  • Video Scaling and Area-Of-Interest (AOI)
  • “Key” Processing
  • Border Colors
  • Image Flip (Horizontal and Vertical)
screen capture of EZwindow4K configuration software

Example Applications

Combine HUD overlay with 4xDVI-D striped video streams using RGB keying

In this example, an EZwindow4K-LL-A#### fuses a standard resolution HUD image (1920×1200 or less) into a striped 4xDVI-D stream. An RGB key with programmable alpha values (separately programmable foreground and background alpha values outside the key area, when Key= TRUE, and when Key = FALSE) results in a realistic HUD overlay. This enables a single projector to be used for both the OTW image and the HUD overlay. Note: If single link outputs are used, then optional DP 1.2 or HDMI outputs are unavailable.
illustration of HUD overlay combined with 4xDVI-D striped video streams using RGB keying

Combine HUD overlay with 1080P video (scaled to 4K with an SP2)

In this example, a SP2 (available separately from Westar) converts a 1080P image into a 3840×2160 image via 4x Single Link DVI streams (each 960×2160), for input into the EZwindow4K. The HUD is created as a 1280×1024 image (or similar). This approach allows the HUD to be displayed in its native resolution on a 4K display device for maximum fidelity. For a given sized HUD, this approach allows 4x the pixel density for the HUD versus using a 1080 display device. This is an excellent method to upgrade projectors or display devices without changing the OTW IG.illustration of HUD overlay combined with 1080P video using RGB keying

Fuse (4) Multi-function display feeds with a high resolution overlay for a part task trainer

In this example, an EZwindow4K-LL-AAAAM2 fuses (4) Multi-function display feeds with a high resolution overlay for a part task trainer. The overlay is generated in a 4kx2k DisplayPort format. The output device is a 4k x 2k DisplayPort 1.2 monitor.

Recommended windowing mode: Regional Windowing (RW) at 4K 60 Hz (IW possible with 4K 30 Hz I/O).

illustration of five video feeds combined into one


UHD I/O (1 UHD input and output included per unit)
I/O Video Type4 x Single Link DVI-D Input and Output
Pixel RateUp to 4 x 166 MPixels/s
Active Pixels per LineUp to 4 x 2176
Lines per FrameUp to 4096
FeatureNo re-timing or re-sizing on inputs
Type A Input Board (max 4 per unit)
Video TypeAnalog RGB (0.7 Volt levels, Interlaced or Non-interlaced)
1xDVI-D, NTSC/PAL, Component, more
Pixel RateUp to 166 MPixels/s
Active Pixels per LineUp to 4096 (constrained by pixel rate)
Lines per FrameUp to 4096
Phase AdjustmentsAdjustable sample clock to ensure center sampling
ConnectorsDVI-I connector for 1xDVI-D and Analog RGB (included)
(3) BNC’s for NTSC/PAL, Component
Optional Mezzanine I/O (1 per unit, either M2 or M6)
M2 MezzanineDisplayPort 1.2 I/O (RGB 4:4:4 mode only)
M6 MezzanineHDMI 2.0 I/O (Input RGB 4:4:4 mode only,
Output RGB 4:4:4, YCbCr 4:2:0 modes)
  • Video Blend (Alpha, RGB, Luma, HSV)
  • Video Scaling, Video Flip
  • Windowing, PIP
  • Convert Interlaced / Non-interlaced
  • Programmable Border Colors
  • Brightness and Contrast Adjustments
Output Sync Modes
  • Free Run
  • External Sync
  • Locked to hi-res input
  • Sync to input
Color Depth8 bits per color
Re-sizing LimitVirtually unlimited
Electro Mechanical
Dimensions1U Rackmount: 19"x13.75"x1.75"
PowerIEC Connector, 100-240 VAC,
47-63 Hz, under 60 Watts
ControlRS-232, USB, Ethernet
Warranty & Certifications
Warranty1 Year Limited

Ordering Information

The standard configuration EZwindow4K-LL comes with the following:

  • EZwindow4K-LL Video Processor
  • RS-232 Serial Cable
  • USB Cable
  • Power Cable

CD Containing

  • Configuration Utility Software
  • User’s Guide
  • Command Line Description

Check out the Options and Accessories and Ordering Configurations tabs for more.

Contact Westar for additional options and accessories
The EZwindow4K-LL has

  • (1) low latency UHD 4xSL DVI input and
  • (1) 4xSL DVI output, plus
  • (4) input board slots, plus
  • (1) mezzanine location that may house various I/O boards.

These slots are populated and configured at the factory. The table below shows the available I/O boards.

I/O BoardFunctionLocations
RGBHV, DVI-D, NTSC/PAL, Component Input Card (only 1 input processed at a time)Any of Slots 1-4
DisplayPort 1.2 I/OMezz
HDMI 2.0 I/OMezz

The I/O boards and their location are defined directly in the part number, in the following format:

EZwindow4K-LL-wxyzm, where:

  • w is the input board type in Slot 1
  • x is the input board type in Slot 2
  • y is the input board type in Slot 3
  • z is the input board type in Slot 4
  • m is the mezz board type

Want to find out more?

If you are interested in more information, send us an inquiry.