Sharper, brighter images thanks to ExwavePRO Technology

All-new CCD designed for security applications

Designing the image acquisition devices used in cameras and camcorders is an expensive, highly specialised business, so it should come as no surprise that security cameras generally use basically the same CCDs for image acquisition as consumer devices. After all, these CCDs are produced using the latest technologies and in such large numbers that costs are kept relatively low. The downside is that these CCD designs are optimised for very different requirements than those that are required in the security or surveillance industry.

Sony is a world-leader in the design and manufacture of CCD and CMOS imaging devices, which are used in a wide variety of products – and not just those which are branded Sony. At the heart of ExwavePRO technology is an all-new CCD design specifically developed to meet the requirements of security applications. The basic imaging technology, ExwaveHAD, is exceptionally efficient at converting light into images. Until now, however, this technology had only been used with interlaced scanning CCDs – typically designed for use in camcorders where interlacing has the benefit of making it easier to capture fast movement at a relatively high resolution.

Interlacing works by splitting each image frame in half, with the sensor scanning every alternative line per frame. In motion, this technique is very effective and is, of course, the basis of both PAL and NTSC TV. For security applications, however, motion is usually a problem. The details of a person or object in motion become more difficult to make out with an interlaced image - the higher the speed, the greater the difference between the two combined interlaced images and the more visual artifacts and blurry an image will seem.

For this reason, all ExwavePRO CCDs use progressive scan technology – which means every frame of video is captured at full resolution with no interlacing. When trying to read the details of a licence plate on a fast-moving car, progressive scan technology effectively doubles the vertical resolution of the image you’re analysing and the practical benefits are obvious.

The below left image was captured with the SNC-DS10 Camera (ExwavePRO) and the right image was captured with a Conventional Camera (Progressive scan CCD with a primary filter) in 0.7 lx Lighting Conditions (actual images).