Fine granularity access in interactive compression of 360-degree images based on rate-adaptive channel codes

TL;DR

This paper introduces a novel interactive compression scheme for 360-degree images that combines efficient data compression with random access capabilities using rate-adaptive channel codes, enabling flexible and transmission-efficient image viewing.

Contribution

It presents a new incremental coding approach based on rate-adaptive channel codes that supports both efficient compression and random access for omnidirectional images.

Findings

Achieves better transmission rates than state-of-the-art tile-based methods.

Provides gradual rate growth with request size, avoiding staircase effects.

Maintains low storage costs while enabling interactive image transmission.

Abstract

In this paper, we propose a new interactive compression scheme for omnidirectional images. This requires two characteristics: efficient compression of data, to lower the storage cost, and random access ability to extract part of the compressed stream requested by the user (for reducing the transmission rate). For efficient compression, data needs to be predicted by a series of references that have been pre-defined and compressed. This contrasts with the spirit of random accessibility. We propose a solution for this problem based on incremental codes implemented by rate-adaptive channel codes. This scheme encodes the image while adapting to any user request and leads to an efficient coding that is flexible in extracting data depending on the available information at the decoder. Therefore, only the information that is needed to be displayed at the user's side is transmitted during the user's request, as if the request was already known at the encoder. The experimental results demonstrate that our coder obtains a better transmission rate than the state-of-the-art tile-based methods at a small cost in storage. Moreover, the transmission rate grows gradually with the size of the request and avoids a staircase effect, which shows the perfect suitability of our coder for interactive transmission.