Development of visibility enhancement for projector display in bright rooms

Feb 05, 2014
Sample video image applying the technology developed.

Hitachi today announced the development of video processing technology enhancing the visibility of high resolution at a rate of 60 frames per second. Enhanced visibility video display was achieved by analyzing the visual characteristics of the video signals to be displayed, extracting key components contributing to visibility, and enhancing those components. As a result, good visibility of projector displayed video can be achieved without increasing the brightness of the projector light source. To enable this technology to be embedded into various products, the processing algorithm for the hardware structure was optimized, achieving real-time processing of high-resolution video in compact hardware. The technology was first developed for the projector but as it can also enhance visibility in surveillance monitors and vehicular displays, it is expected to find a wide range of application.

With projectors, images are converted to light and then projected onto a screen. If the screen is too bright due to strong ambient light, the clarity of the projected image deteriorates and so conventionally, a room is dimmed. In recent years however projectors are increasingly being used in brighter environments due to improvements in projector light source and in combination with mobile terminals such as smart phones and tablets.

In order to support such needs, Hitachi has developed video to enable increased visibility of video images under various ambient levels of brightness. Hitachi Maxell, Ltd., responsible for developing, producing and marketing Hitachi's projectors, has incorporated this technology in the development of an ultimate short throw projector with enhanced visibility, and will be releasing the product in the US and Europe first, followed by other regions.

Conventional processing to enhance visibility includes contrast compensation and color management. These methods however process the entire image displayed as a whole, resulting in an undesirable "side-effect" of reducing visibility in local portions of the image which did not require compensation in the first place, making it difficult to achieve a significant overall improvement through compensation. The technology developed analyzes local characteristics such as brightness and resolution in an image, and compensates by adjusting the characteristics in each locality to reduce the "side-effects" and provide significantly enhanced visibility. Features of the technology are as follows:

Visibility enhancement algorithm based on Retinex theory

A new video compensation algorithm was developed based on the Retinex Theory which models human vision. In this algorithm, several which affect visibility are separated, and depending on characteristics of the video such as brightness, resolution, and color composition, the optical components are enhanced. As a result, the following features were achieved:

(a) Texture: The perception of "sharpness," "gloss" and "shade" were enhanced to improve the clarity of the outline of objects within the video
(b) Contrast: The visibility of the dark regions within a video image were enhanced without influencing the bright regions
(c) Color rendering property: The images were reproduced with vivid coloring without losing any of the original color information

Real-time processing of high resolution video and compact size

In general, as video compensation based on the Retinex Theory requires a large amount of calculation to separate the optical components, the size of the logic circuit and processing time were issues. In order to enable the algorithm developed to be embedded in a product, the processing sequence and tasks which separate, enhance and synthesize the optical components in the video image were optimized to increase the efficiency of the logic circuits inside the hardware; achieving compact logic circuits capable of real-time processing (60 frames/second) of not only still images but also high resolution video (1920 x 1200 pixels). By applying this technology, it will become possible to achieve enhanced visibility high resolution video displays not only in business applications such as in presentations but also in home theatre and amusement applications which require , such as movies and broadcasted contents.

Further, as the above processing can be achieved with compact hardware (17x17mm), it can be easily be mounted on small electronic boards such as those for compact projectors and a wide range of applications is expected.

Hitachi Maxell, which develops, produces and markets Hitachi's projectors has developed an ultimate short throw projector embedding this technology, and intend to market this in the US and European, followed by other regions. Hitachi plans to provide the technology as part of visibility enhanced video display solutions for applications such as in-vehicle and surveillance monitors.

Explore further: Sony develops 4K ultra short throw projector

add to favorites email to friend print save as pdf

Related Stories

Sony develops 4K ultra short throw projector

Jan 08, 2014

Sony today announced the development of a state-of-the-art 4K Ultra Short Throw Projector featuring a stylish, furniture-like design. Utilizing space itself, it can be placed near most walls and has the ability ...

Micromirror technology for smartphones

Jul 16, 2013

With consumers using smartphones as a mobile entertainment centre, the ability to project photos and videos on any surface may soon become the norm.

Recommended for you

Neuroscientist's idea wins new-toy award

20 hours ago

When he was a child, Robijanto Soetedjo used to play with his electrically powered toys for a while and then, when he got bored, take them apart - much to the consternation of his parents.

Land Rover demos invisible bonnet / car hood (w/ video)

Apr 14, 2014

(Phys.org) —Land Rover has released a video demonstrating a part of its Discover Vision Concept—the invisible "bonnet" or as it's known in the U.S. the "hood" of the car. It's a concept the automaker ...

Visions of 1964 World's Fair didn't all come true

Apr 12, 2014

Video phone calls? Yeah, we do that. Asking computers for information? Sure, several times a day. Colonies on the moon and jet packs as a mode of everyday transportation. OK, maybe not.

User comments : 0

More news stories

Intel reports lower 1Q net income, higher revenue

Intel's earnings fell in the first three months of the year amid a continued slump in the worldwide PC market, but revenue grew slightly because of solid demand for tablet processors and its data center services.

Low Vitamin D may not be a culprit in menopause symptoms

A new study from the Women's Health Initiative (WHI) shows no significant connection between vitamin D levels and menopause symptoms. The study was published online today in Menopause, the journal of The North American Menopa ...

Astronomers: 'Tilt-a-worlds' could harbor life

A fluctuating tilt in a planet's orbit does not preclude the possibility of life, according to new research by astronomers at the University of Washington, Utah's Weber State University and NASA. In fact, ...