Title :
Low bit-rate coding of image sequences using adaptive regions of interest
Author :
Doulamis, Nikolaos ; Doulamis, Anastasios ; Kalogeras, Dimitrios ; Kollias, Stefanos
Author_Institution :
Dept. of Electr. & Comput. Eng., Nat. Tech. Univ. of Athens, Greece
fDate :
12/1/1998 12:00:00 AM
Abstract :
An adaptive algorithm for extracting foreground objects from background in videophone or videoconference applications is presented. The algorithm uses a neural network architecture that classifies the video frames in regions of interest (ROI) and non-ROI areas, also being able to automatically adapt its performance to scene changes. The algorithm is incorporated in motion-compensated discrete cosine transform (MC-DCT)-based coding schemes, allocating more bits to ROI than to non-ROI areas. Simulation results are presented, using the Claire and Trevor sequences, which show reconstructed images of better quality, as well as signal-to-noise ratio improvements of about 1.4 dB, compared to those achieved by standard MC-DCT encoders
Keywords :
adaptive signal processing; discrete cosine transforms; image classification; image reconstruction; image segmentation; image sequences; motion compensation; neural net architecture; teleconferencing; transform coding; video coding; videotelephony; MC-DCT based coding; MC-DCT encoders; adaptive algorithm; adaptive regions of interest; background; foreground objects extraction; image sequences; low bit-rate coding; motion-compensated discrete cosine transform; neural network architecture; nonROI areas; performance; reconstructed image quality; scene changes; signal-to-noise ratio; simulation results; video frames classification; videoconference application; videophone; Bit rate; Head; Image coding; Image reconstruction; Image sequences; Layout; Neural networks; Transform coding; Video compression; Videoconference;
Journal_Title :
Circuits and Systems for Video Technology, IEEE Transactions on
