Logi-Zoom: video recorder side digital zoom function
Remote accessibility and remote management of video surveillance systems is a basic requirement today. In case of analogous systems it can usually be implemented with the normal and accepted quality and payable bandwidth. In case of megapixel, multi-.megapixel video monitoring system the available and the required bandwidth is a more problematic issue. The purpose is to make the additional information provided by the multi-megapixel systems available with maintaining an acceptable level of network traffic and bandwidth.
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Analogous video monitoring systems
In case of analogous video monitoring systems the resolution of the image displayed on the monitor is usually the same as that of the camera (25 KB/image). Therefore, further digital zoom does not provide additional information; one does not recognize, see additional details. Zooming only results in pixel visualization on the image.
Multi-megapixel video monitoring systems
The situation is different with the multi-megapixel video monitoring systems where the resolution of the camera is usually higher than the displayed one on the monitor. There is less space on the screen as the real size of the images i.e. the image can be displayed in a resolution significantly less than the actual resolution. One can get additional information and detail by digital zooming of the image. However, to achieve this one can forward the multi-megapixel image to a control site (500 KB/image). A network with significantly wide bandwidth is required to transmit the increased amount of data.
Logipix multi-megapixel video monitoring system
What happens, however, if a network with limited bandwidth is only available? In this case the transmission of multi-megapixel images would be performed only with very low frame rate frequency or not at all. This is solved by the video monitor side digital zoom function of Logipix, the Logi-zoom.
The JPEG2000 compressing procedure utilized by the system allows transmission of an image to the control site with the displayed size which has much lower resolution (25 KB/image), and not the recorded multi-megapixel image. This way, however, we would have an image with low resolution i.e. as with the analogous systems we would not see, recognize more details with the digital zoom. Therefore, it is reasonable to achieve that the display-dependent flexibility of the resolution should be workable not only for the entire image but for the selected sections of the image as well.
This is achieved by Logi-zoom by sending the selected image section through the network to the supervision software in a resolution required to display. Thus instead of sending the high resolution image, we transmit the image section selected by digital zoom to the control side even at multi-megapixel resolution (+25KB). This function can be utilized both with live and archive images. Transmission of the significant additional information of multi-megapixel cameras is provided by Logi-Zoom function at the video recording side and by optional displaying opportunities ensured by JPEG2000 at client side beside the same magnitude of data traffic as at analogous systems.