US Patent Application 18296351. Block-Based Low Latency Rate Control simplified abstract

From WikiPatents
Jump to navigation Jump to search

Block-Based Low Latency Rate Control

Organization Name

Apple Inc.


Inventor(s)

Felix C. Fernandes of Saratoga CA (US)

Block-Based Low Latency Rate Control - A simplified explanation of the abstract

This abstract first appeared for US patent application 18296351 titled 'Block-Based Low Latency Rate Control

Simplified Explanation

The patent application describes a method for controlling the encoding rate in an encoding system that uses wavelet transform to decompose pixel blocks into subbands stored as wavelet blocks (WBs).

  • Wavelet transform is used to decompose pixel blocks into subbands for encoding.
  • Quantization parameters (QPs) for the subbands are estimated to minimize distortion while staying within a rate limit.
  • Rate and distortion curves are generated for each subband using unquantized DCT histogram and bit count statistics.
  • A bisection search is used to find points on the curves where the slope is the same for all curves.
  • The QPs associated with these equally sloped points are the optimal QPs for the wavelet block.


Original Abstract Submitted

Block-based, low latency rate control for an encoding system in which a wavelet transform decomposes pixel blocks into subbands stored as subbands in wavelet blocks (WBs) for encoding. Quantization parameters (QPs) for the subbands in each WB are estimated using a method that minimizes wavelet-inverse distortion given a rate bound. For each subband, a rate curve is generated based on an unquantized DCT histogram and bit count statistics for the subband, and a distortion curve is generated based on the unquantized DCT histogram and a distortion estimate for the subband that is estimated using a masked estimator. Once the rate-distortion curves for the subbands are generated, a bisection search may be used to find a point on each curve where the slope is the same for all the curves. The QPs associated with those equally sloped points are the global minimizing QPs for the wavelet block.

Retrieved from "http://wikipatents.org/index.php?title=US_Patent_Application_18296351._Block-Based_Low_Latency_Rate_Control_simplified_abstract&oldid=6672"