Axis Communications 243Q Blade user manual An I-VOP is a complete image frame

AXIS 243Q Blade - Glossary 69

analyzing image data and differences in series of images. This detection can, for example, be used to trigger an alarm event in a network camera and start the upload of images from the camera.

Video switcher - An analog video switcher sequentially displays full screen images, from one camera after another, typically at 3-5 seconds intervals. Other camera sources are not recorded while the image source from one

VOP (Video Object Plane) - A VOP is an image frame in an MPEG-4 video stream. There are several types of VOP:

-An I-VOP is a complete image frame.

-An P-VOP codes the differences between images, as long as it is more efficient to do so. Otherwise it codes the whole image, which may also be a completely new image.

Web camera (Webcam) - A camera that requires a constant connection (via e.g. USB) to a PC for its operation. See also Network camera.

Web server - A program that allows web browsers to retrieve files from computers connected to the Internet. The Web server listens for requests from browsers and upon receiving a request for a file sends it back to the browser. The primary function of a Web server is to serve pages to other remote computers.

Zoom lens - A zoom lens can be moved (zoomed) to enlarge the view of an object to show more detail.