3D Video: From Capture to Diffusion

Chapter 19

3D HDR Images and Videos: Acquisition and Restitution

19.1. Introduction

The human eye is able to perceive up to 10 orders of magnitude of light intensity (10¹⁰ cd m⁻²), but only 5 simultaneously (see [FER 01] and Chapter 2). This order of magnitude is reduced to 2 when displaying images on standard screens. Images acquired up to now, known as low dynamic range (LDR) images, contain a limited range of light intensities. This restriction is highlighted in scenes involving back lighting, for example. For this reason, the development of images with high color dynamics, or high dynamic range (HDR), is increasingly important.

This type of image has recently been the subject of considerable research effort, focusing on acquisition, storage, display and use. Specific HDR cameras already exist, but are either still at the experimental stage or too costly. Methodologies have been established to compensate for the absence of specific material. An introduction to HDR images and classic acquisition methods is presented in Chapter 2, in which we see that static image capture has been the subject of particular attention. Current sensors allow us to acquire and directly store a wider dynamic range of colors (up to 16 bits for still cameras). HDR video has recently attracted much attention, but video sensors remain limited in terms of color intensity ranges (mainly represented in 12 bits). For now, it is difficult to transmit and store HDR video data in the absence of effective formats. ...