Compressed Exposure Sequences for HDR Imaging

High dynamic range (HDR) imaging techniques allow photographers to capture the luminance distribution in the real-world as it is, freeing them from the limitations of capture and display devices. One common approach for creating HDR images is the multiple exposures technique (MET). This technique is preferred by many photographers as multiple exposures can be captured with off-the-shelf digital cameras and later combined into an HDR image. In this study, we propose a storage scheme in order to simplify the maintenance and usability of such sequences. In our scheme, multiple exposures are stored inside a single JPEG file with the main image representing a user-selected reference exposure. Other exposures are not directly stored, but rather their differences with each other and the reference is stored in a compressed manner in the metadata section of the same file. This allows a significant reduction in file size without impacting quality. If necessary the original exposures can be reconstructed from this single JPEG file, which in turn can be used in a standard HDR workflow.