X-bit labs

S3 GammaChromeS18 Graphics Processor Preview (page 8)

Category: Video

by Anton Shilov , Anna Filatova

[ 03/14/2005 | 07:34 AM ]

DeepColor

Besides the traditional TrueColor mode, S3G GammaChrome also supports DeepColor mode, which can display up to a billion colors. This mode works just like the Matrox GigaColor technology: it reduced the width of the alpha-channel to 2 bits thus increasing the precision of R, G and B color channels by 2 bits each. This way, DeepColor is configured as 10:10:10:2, while all traditional video modes use 8:8:8:8 formula. In other words, it uses 30 bits to display the color information against the traditionally used 24 bits.

It is known that most digital cameras and photo scanners produce images with 10bit+ color precision per component. However, since the standard PC video system is limited to 8bit per component, a lot of small details get lost when the image is displayed on the monitor. DeepColor allows avoiding this loss of information, because in this mode the color palette is 64 times larger than in the standard TrueColor mode.

In monochrome display mode DeepColor offers 1024 distinct shades of gray, which is 4 times more precise than what we can get in the standard mode. This feature makes DeepColor technology very efficient for the medical applications, such as X-Ray photographs for instance, where smallest details are all displayed in different shades of gray. S3G DeepColor technology will hardly be efficient for games, however, it undoubtedly has enormous potential in some other fields.

Hi-Def Experience

HDTV encoder built into the GammaChrome chip supports all existing standards including 1080p and has the following features:

• Comprehensive support for all 18 ATSC standards
• Support for 1080p mode for ultimate HDTV
• Component Video (YPbPr) output
• 4:4:4 conversion with 10 bit DAC resolution
• ChromoVision full screen video on HDTV or TV
• Full desktop view in HDTV mode
• 480i, NTSC/PAL standard TV output (S-video, composite)
• Macrovision compliant
• 2/3 tap flicker filter with programmable coefficients
• Vertical over/under-scan compensation
• Adaptive aperture correction
• ChromoColor™, including full range RGB to YUV color space conversion with Hue, Saturation and Contrast adjustment
• Smooth vertical overscan compensation with programmable contraction factor

Due to this broad functionality in terms of video playback and processing, as well as due to the CCIR656 and I2S interfaces support, S3G GammaChrome turns out an excellent solution for home entertainment systems using Windows XP Media Center Edition operating system.