Digital View Blog

Many people associate night-vision with red or green images however when designing a display system that optimizes image detail and preserves a users ability to see in low light other factors are worth considering:

• Color palette: Tuning the color palette for night-safe colors may help preserve image information and usability. Factors to consider:
  • De-saturating shorter wavelength colors, ie those towards the blue end of the spectrum.
  • Adjusting the gamma curve to emphasize detail in low light areas of the image.
  • Combining all colors to Red mono or Green mono.
  • Using the Red or Green channel only.
• Brightness: When working in a low light environment a night-save setting may require a maximum limit on the display brightness setting. When invoked it makes sense that brightness adjustment operates with a suitable level of adjustment resolution over the new limit.
• Controls: Being able to invoke the night-safe easily and effectively will be a key element:
  • Auto settings: For example an light sensor is used to invoke the night-safe settings.
  • External control: This is where external equipment switches the display system to its night-safe settings, it could be a clock or as part of a larger display and system infrastrcture.
  • User control: To make things easy for a user a single button access for night-safe settings as well as controls that remain readily accessible and readable in low light conditions.

IMAGES

The top image is the original; the 2nd is with blue removed, gamma adjusted to bring out detail in shadows and is suitable for having the brightness reduced in low light conditions; the 3rd image is red only; the 4th is green only. (Note: It seems that the pictures align properly on the right in Firefox and Safari but not in Internet Explorer).

Various Digital View controllers support all of the above, details can be found from the individual controller manuals, the application notes for RS-232 and the Serial Utility as well as from Digital View directly. A good model to consider is the SVX-1920 or upcoming harsh environments version the HX-1920.

Touchscreens are in fashion, popularized initially by kiosks but most recently by smart-phones led by the Apple iPhone they are also being used for interactive retail media systems. But what about buttons – the humble button deserves consideration, it is intuitive and low cost, easy to install and reliable. The following is a brief look at some of the issues…

• Intuitive: Buttons are very intuitive, you see a button you know it is there to be pressed. Touchscreens need content that makes it clear that the display is touch-sensitive and where to touch.
• Cost: Generally buttons will be lower cost, possibly by a very considerable margin.
• Space: Buttons need space whereas touchscreens only take up the space of the display, this can be a key factor for shelf-edge displays in retail.
• Reliability: Both are likely to be quite reliable though touch panels may suffer from being too sensitive or not sensitive enough
• Feedback: You know when you have pressed a button but with a touchscreen users are never quite sure until the system responds.
• Dynamic function: With a touch screen it is relatively easy to make the button function context sensitive. Buttons can have on-screen descriptions (as with ATM cash machines) but that can lead to alignment issues.
• Calibration: Buttons don’t need calibration, neither do segment type touch screens.
• Design: Buttons come in all shapes, sizes and with a range of design and labeling options.
• Personal preference: Very often a key deciding factor.

So don’t forget buttons – they are very engaging.