Genoa and Philips Demo Five-Color Projection System
Royal Philips Electronics (Eindhoven, Netherlands) (http://www.philips.com/) and Genoa Color Technologies (Herzeliya Pituach, Israel) (http://www.genoacolor.com/) teamed up at SID'03 to reveal front- and rear-projection systems that feature a color space that uses five primary colors instead of the standard red, green and blue. The systems were the talk of SID as they indeed were able to show colors not typically seen in RGB systems, such as turquoise, deeply saturated greens and reds, as well as rich golds.
Genoa developed the IP behind the five-color system. It is a two-and-a-half-year old VC-funded company whose founders have roots in the pre-press industry. It has developed mapping algorithms that can convert ordinary RGB or YCbCr signal data into alternative color space coordinates with four, five, or even six primary colors. This was initially implemented in software and demonstrated on a spectrally accurate monitor, but it has also developed FPGA-based hardware versions too. The company has more than 35 patents issued or pending.
Genoa says its goal is to develop a system that would enable projectors that can reproduce the colors of film. It demonstrated this technology in a suite at SID'03. To do this, it used an unmodified DLP-based Plus projector to show conventional projection images and a pair of modified Plus projectors that showed the five-color images. Genoa says the two Plus projectors were only modified with different color wheels, made by Unaxis. A software implementation changes a standard RGB signal from a DVD to "Genoa color coordinates," which are fed to the five-color projector pair. The two systems project identical images on a screen with the five-color projector pair using neutral density filters to balance the light outputs. The idea is to make the systems identical in almost all aspects - except the color space.
The demo is impressive. Some scenes, like a Caribbean ocean, clearly showed the beautiful turquoise color of the water with the five-color system.
Golds have a more yellow and richer color while greens and reds are more saturated. Genoa says these colors are in the DVD color encoding and their algorithms can pull it out. This software implementation required the frame rate of the movie to be slowed down on the five-color projection system, but the hardware implementations can be done in real time.
The system uses red, green, blue, cyan and yellow as its primaries, but the RGB filters need to be modified to better match with the other two colors. Using the yellow color coupled with a UHP lamp has a side benefit - the yellow notch filter can be eliminated and that light now used in a primary color, thus increasing brightness. Genoa says this five-color system will have little impact on the bill of materials of the projectors, and so believes there will be significant benefits for integrators and TV viewers.
Philips has apparently investigated Genoa's IP and has negotiated an exclusive license for RPTV applications. However, licenses for other applications remain open, says Genoa.
Philips demonstrated the five-color system in an RPTV on the show floor at SID. It declined to detail what engine architecture it used, but did say it was a single-panel LCOS engine design. Doing an engine with five spinning prisms seems difficult, so we would assume it is a modified color drum approach. Amazingly, the demo was put together in only four months. The modified engine was fitted into the same cabinet that will house Philips spinning-prism LCOS RPTVs, which are set to launch this summer.
One might think that a single panel would need to operate quite fast to display five color fields. However, Philips assured us that the current single LCOS panel was up to the task. We did not see any effects like color break up or a slow frame rate in the demonstrator on the show floor.
The five-color set attracted a large crowd at SID and the image quality was impressive. While some of the colors looked very good, we thought others would need to be adjusted in the next design as they took on an almost fluorescent glow.
Philips has not yet committed to produce the set and was using SID as a first setting to gather feedback about the concept. We think the benefits of higher brightness, wider color space and minimal cost impact are very compelling. Philips likes it too and thinks such sets will give it a significant marketing and showroom selling advantage. We agree. Fine-tune the colors and verify there are no other performance or cost issues - and if all looks good, then go for it.