System Components designed specifically for harsh transit environments

Progressive Scan vs Interlaced

The negative effects of interlacing have always been an issue when recording scenes with high activity – particularly in the horizontal plain. This occurs when digitally recording at the highest possible PAL or NTSC resolution from analogue cameras. The digital recorder is required to record at full frame resolution by interlacing the odd and even fields from the cameras video signal. As there is typically a 16ms gap between fields, objects moving through the scene suffer tearing, rendering the footage useless. This problem is not as noticeable in a bus saloon when vehicle occupants move slowly in the vertical plain, up and down the centre aisle. However, as soon as there is any lateral movement the result is severe tearing or feathering on the edges of the moving object.

Progressively scanning an image has numerous benefits when applied to mobile applications. Unlike analogue cameras, DTI’s progressive scan digital cameras produce video streams from images that are progressively scanned, ensuring sharp edges on even the fastest moving objects in  both horizontal and vertical plains.

For almost 5 years DTI have been pushing the benefits of progressive scan technology for mobile high activity scenes. Today virtually all DTI systems have at least one high definition progressive scan digital camera covering critical camera views such as: forward facing or the drivers area. The success rate of capturing a clear image increases tenfold with DTI’s digital cameras.

System Components