At first, IP and analog cameras may seem more alike than they are
different. Both cameras employ an analog image sensor, which is either
CCD (charge coupled device) or CMOS (complementary metal oxide
semiconduc-
tor). Virtually, all analog cameras use a CCD sensor and IP cameras can
utilize either type. The analog signal from the sensor is then
converted to digital form by an analogto-digital converter and further
processed by the
camera’s onboard digital circuitry (DSP). For an IP camera the image is then compressed internally (encoded) and
transmitted via an IP protocol (Ethernet) and is either stored in the camera or on a network video recorder (NVR).
For an analog camera, the image is then converted back to analog by a
digital-to-analog converter so the image can be transmitted to a video
monitor or a digital video recorder (DVR), where the image is encoded
and stored. At this point, it seems the difference between the two
types of cameras is negligible. Primarily, the difference is where the
video is compressed and what components it utilizes. There are,
however, significant qualitative differences between CMOS and CCD
sensors, with CCD holding a demonstrable advantage in image quality
over CMOS.
Article ID: 107, Created: July 14, 2009 at 11:21 AM, Modified: July 14, 2009 at 11:21 AM