Events

 
MPhil Thesis Presentation
Digital Photo Album Compression and HEVC Related Issues

by Ms Ruobing ZOU

Date
 :  14 Jan 2013 (Mon)
Time
 :  10am
Venue  :  Room 2463, 2/F (Lifts 25-26), HKUST

Examination Committee
Prof Roger S K CHENG, ECE/HKUST (Chairman)
Prof Oscar C L AU, ECE/HKUST (Thesis Supervisor)
Prof Li QIU, ECE/HKUST
 
Abstract
In recent years, the advance in computer, IC, internet, cloud, and multimedia technologies have led to widespread usage of digital photos and videos in our everyday multimedia-enabled lives. A consumer can easily have many photo albums each of which contain many JPEG images taken in the same occasion. Typically many photos taken in the same occasion are similar, with similar people and background. With explosive growth of photo albums in the consumer’s personal computer and in the cloud (such as facebook, twitter, Google, Renren, etc), the cost to store and transmit such digital images can be very significant. Thus it is important to compress these images efficiently. In this thesis, we propose some novel effective photo album compression algorithms to achieve higher compression efficiency than existing methods.
 
Observing that many images in albums are similar, we assume that similar images can be clustered and identified and we develop efficient ways to compress each set of similar JPEG images using video coding techniques. Our approach is to arrange all the similar images into some kind tree structure with many roots and branches and then apply video coding technique along each branch. To maximize the inter-frame correlation between adjacent photos along the branches in a tree, we consider both the minimum spanning tree (MST) and the minimum spanning forest (MSF) to achieve minimum inter-frame prediction cost. As an unconstrained tree can be very deep which can result in very long delay during random access, we consider trees with limited depth to achieve good random access performance. Taking advantage of the latest High Efficiency Video Coding (HEVC) standard, we consider several possible HEVC frame configuration in search of the best. Our methods can support common photo albums operations such as addition of new images, deletion of useless images and modification of existing images. Experiments suggest that the proposed methods can achieve significant gain in coding efficiency compared with the common JPEG format.
 

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