Media.Player

JPEG/MPEG Decoder-Compatible Optimized Thresholding for Image and Video Signal Compression

Summary

Lead Inventors: Kannan Ramchandran, PhD, Martin Vetterli, PhD, Yanbin Yu PhD, Dimitris Anastassiou, PhDProblem or Unmet Need:Good compression when using JPEG and MPEG decoders results from determining an optimal thresholding strategy for the DCT (discrete cosine transform) coefficients. Thresholding, or dropping, the less significant DCT coefficients, while having a marginally negative impact on coded quality, could result in a significant reduction in coding bit rate as fewer coefficients would need to be transmitted. However, determining which DCT coefficients to drop and maintain decoder compatibility can be problematic.The technology comprises an optimal algorithm that uses a fast dynamic programming recursive structure. This novel low complexity dynamic programming method exploits the monotonic nature of bit rate versus zero run-length characteristics of JPEG and MPEG standards.

Technology Benefits

Optimizes the encoder thresholding operation while maintaining compatibility with standard JPEG and MPEG decoders.

Technology Application

The optimization of delivered coding quality and signal-to-noise ratio for JPEG and MPEG while maintaining compatibility with existing decoders.

Detailed Technology Description

The technology comprises an optimal algorithm that uses a fast dynamic programming recursive structure. This novel low complexity dynamic programming method exploits the monotonic nature of bit rate versus zero run-length characteristics of JPE...

*Abstract

None

*Inquiry

Calvin Chu Columbia Technology Ventures Tel: (212) 854-8444 Email: TechTransfer@columbia.edu

*IR

MS92/01/25

*Principal Investigator

*Publications

http://goo.gl/sn5PWhttp://goo.gl/inuI6http://goo.gl/EKfPW1) Ortega, A.; Ramchandran, K., "Rate-distortion methods for image and video compression," Signal Processing Magazine, IEEE , vol.15, no.6, pp.23-50, Nov 19982) Crouse, M.; Ramchandran, K., "Joint thresholding and quantizer selection for transform image coding: entropy-constrained analysis and applications to baseline JPEG ," IEEE Transactions on Image Processing, vol.6, no.2, pp.285-297, Feb 19973) Ramchandran, K.; Vetterli, M., "Rate-distortion optimal fast thresholding with complete JPEG/MPEG decoder compatibility," IEEE Transactions on Image Processing, vol.3, no.5, pp.700-704, Sep 19944) Ramchandran, K.; Ortega, A.; Vetterli, M., "Bit allocation for dependent quantization with applications to multiresolution and MPEG video coders," IEEE Transactions on Image Processing, vol.3, no.5, pp.533-545, Sep 1994

*Web Links

USPTO: US 5,734,755

Country/Region

USA