A plurality of picture data storage/retrieval apparatuses are connected to each other through a communication line. Each picture data storage/retrieval apparatus has a two-dimensional scanning device for inputting picture data, a keyboard for entering control data, an optical disk for storing the picture data input through the two-dimensional scanning device, a floppy disk for storing a control program, a CRT display device for displaying the picture data stored in the optical disk, a printer fo...

A scan path is generated using one or more two-dimensional sets of training signals. For encoding, a two-dimensional set of signals is encoded using the scan path. For decoding, a two-dimensional set of encoded signals is decoded using the scan path. In a preferred embodiment, a plurality of different scan paths are generated for a plurality of quantization levels; signals are transformed and quantized using selected quantization levels; and the quantized, transformed signals are encoded using t...

A two-way audio communication system is designed to allow basic audio communication between two users on a common computer network. The audio communication system of the present invention is designed to work in the background of the computer, so the user can work on other software applications simultaneously. In a half-duplex embodiment (i.e., only one user can talk at a time), if at least two users try to talk at the same time, an arbitration scheme is employed to settle the dispute. The winner...

A bit pointer is updated by a specified value; and a byte pointer is updated in accordance with a lookup table and the updated bit pointer.

A quantization level is selected for the current video frame in accordance with a plurality of mappings, wherein each mapping correlates an activity measure with a bits per frame measure and each mapping corresponds to a quantization level of a plurality of quantization levels. The current video frame is encoded in accordance with the selected quantization level.

Video signals are encoded using quantization matrices generated based on one or more quantization matrix parameters that are contained in the encoded bit stream. Encoded video signals are decoded using quantization matrices generated using the one or more quantization matrix parameters that are contained in the encoded bit stream.

A system and method is provided for encoding data wherein contiguous data values represent a video image. Three contiguous data values are applied to a loop filter to provide digital filtering of the data values. A frame differencing device performs a subtraction operation upon one of the three contiguous data values simultaneously with the performance of a filtering operation upon another one of the three contiguous data values. Additionally, a discrete cosine transform device performs transfor...

A plurality of specially equipped personal conference managers (PCMs), one each, are provided to a plurality of personal conference systems (PCSs), and a plurality of specially equipped multi-point conference managers (MCMs), also one each, are provided to a plurality of multi-point control units (MCUs) interconnecting the PCSs. Each PCM is equipped with a first plurality of data routing matrix management functions for creating, updating, and deleting a plurality of data routing matrices specify...

Each PC conferencing application of a plurality PC conferencing systems is equipped with an enhanced profile function including the ability to allow a user to designate a personal address book, and a corporate address book. Each PC conferencing application is further equipped with functions for modeling exchange of business cards, including functions for creating, editing, sending, receiving, saving, and browsing electronic business cards. As an integral part of the bizcard create and edit proce...

A conference enabled X windows networking system using a method for determining the best match available for a conference owner's visual type is disclosed. In the system, the enabler determines if the visual type detected in the X protocol stream is the conference owner's default visual type, in which case it is matched to the participant's default visual type. If that is not the case, the system determines if a visual type is available on the participant which is compatible to that being referr...