November 1, 2011

Accurate colour images at 30 frames per second at 0,1 lux.

Pixim was present at IFSEC for the first time on the C-Video Concepts stand. In this article, Pixim’s David Beech introduces the company’s technology to use.

Finding the right security camera for every application is challenging. Different scenarios create the need for a wide range of cameras:

An environment that is backlit, such as the inside of a building or vehicle looking outside requires a camera that offers wide dynamic range (WDR). Dynamic range is the ratio of the brightest image that can be captured by the imaging system to the darkest image that can be captured simultaneously in the same video frame. Light intensity greater than the brightest possible that can be handled will cause the image sensor to saturate to white, while light intensity less than the darkest possible will not register resulting in black areas of the scene. Both of these conditions distort the image, hiding potentially vital information. WDR cameras are capable of capturing highlight and shadow detail – including backlit images – in the same scene.

Some situations need cameras that are capable of capturing natural colour in any lighting. For instance, security personnel watching monitors in casinos need to be able to distinguish between red and black playing cards in both well-lit and lowlight areas. Natural colour is also important in identifying people where subtle variations in skin tone and clothing shades can make a difference when identifying and prosecuting a criminal suspect.

Video is often used for licence plate identification and facial recognition. These scenes require high-resolution cameras which make it easy to distinguish image features and details.

Additional challenges for security cameras include lighting issues such as glare and reflections. These problems can cause image artifacts including vertical smear and pixel blooming which make the video unusable.

Lowlight is the final challenge. Envision a warehouse with an indoor camera aimed at its loading dock door. The camera’s WDR allows it to get clean images of both the inside of the warehouse and the outside dock. However, at night, only emergency lights are kept on. Unfortunately, for most cameras low light equals no colour, limited dynamic range, high levels of noise, or in the worst case, no image at all (black).

One solution is to add more light, which is expensive, and another is to use true day night (TDN) cameras. TDN cameras can produce an image in lowlight but without colour due to their reliance on infrared light. A security guard, the police, or a prosecuting attorney will not be able to tell the bad guy in the red shirt from the good guy in the blue.

The answer to challenging lighting

A new camera chip can now meet all of the challenges listed above. The Seawolf chip by Pixim, a provider of imaging technology for enterprise security cameras, offers the industry’s highest effective resolution, greatest wide dynamic range and best lowlight performance. Cameras based on Seawolf can handle backlight situations, capture realistic colour and eliminate glare in all lighting conditions – night and day. Seawolf cameras need just 0,1 lux to produce accurate colour images at a full 30 frames per second.

Seawolf is based on Pixim’s unique imaging technology. Unlike traditional image capture technologies, where each pixel cannot adjust to highlights and lowlights in the same scene, Pixim’s patented Digital Pixel System technology empowers hundreds of thousands of pixels to act like individual cameras constantly self-adjusting. This all-digital system enables Pixim-powered cameras to efficiently capture the whole picture, regardless of lighting condition or application – thus securing the highest resolution, natural colour and clarity, while automatically eliminating image-compromising visual noise.

Boasting 690 HTVL effective, Seawolf delivers the highest usable resolution. Traditional, analogue CCD-based cameras lose much of their resolution when the video is recorded and reviewed. However, due to Seawolf’s high total resolution (horizontal times vertical), its high-quality, colour images are preserved by commonly used DVRs and displays.

Seawolf-powered analogue and IP cameras produce noise-free, clean images which require less hard drive space to store video content. Users of IP cameras will benefit from Seawolf’s global electronic shutter, progressive scan image capture, and full D1 resolution at 30 frames per second.

For more information contact C-Video Concepts, +27 (0)31 309 1048, andy@cvideoconcepts.co.za, www.cvideoconcepts.co.za