公开(公告)号：US11716476B2

公开(公告)日：2023-08-01

申请号：US17663983

申请日：2022-05-18

Applicant: Dropbox, Inc.

Inventor： Daniel Horn ,  Ken Elkabany ,  Keith Winstein

IPC: G06T9/00 ,  H04N19/176 ,  H04N19/625 ,  H04N19/13 ,  H04N19/593 ,  H04N19/91 ,  H04N19/14 ,  H04N19/18 ,  H04N19/48 ,  H04N19/40 ,  H04N19/124 ,  H04N19/46 ,  H04N19/132 ,  H04N19/42 ,  H04N19/436

CPC classification number: H04N19/176 ,  H04N19/124 ,  H04N19/13 ,  H04N19/14 ,  H04N19/18 ,  H04N19/40 ,  H04N19/48 ,  H04N19/593 ,  H04N19/625 ,  H04N19/91 ,  H04N19/132 ,  H04N19/42 ,  H04N19/436 ,  H04N19/46

Abstract: Techniques for lossless compression of a digital image using prior image context.

公开(公告)号：US20190098321A1

公开(公告)日：2019-03-28

申请号：US16205114

申请日：2018-11-29

Applicant: Dropbox, Inc.

Inventor： Daniel Horn ,  Ken Elkabany ,  Keith Winstein

IPC: H04N19/176 ,  H04N19/124 ,  H04N19/14 ,  H04N19/40 ,  H04N19/48 ,  H04N19/18 ,  H04N19/13 ,  H04N19/593 ,  H04N19/91 ,  H04N19/625 ,  H04N19/42 ,  H04N19/436 ,  H04N19/132 ,  H04N19/46

Abstract: Techniques for image recompression. In one implementation, the techniques are implemented to recompress a baseline joint photographic experts group (JPEG) image with compression savings. The techniques replace the Huffman coding of baseline JPEG with an arithmetic coding that uses a sophisticated adaptive probability model. The arithmetic coding techniques avoid global operations such as global sorting that would prevent distributed and multithreaded decompression operations when recovering the original JPEG image from the recompressed image. At the same time, the techniques realize substantial compression savings relative to baseline JPEG, on average 23% compressing savings in some implementations.