High dynamic range light fields via weighted low rank approximation

Mikaël Le Pendu (1, 2) , Aljosa Smolic (2) , Christine Guillemot (1)

1 Sirocco - Analysis representation, compression and communication of visual data
2 Trinity College Dublin

In this paper, we propose a method for capturing High Dynamic Range (HDR) light fields with dense viewpoint sampling. Analogously to the traditional HDR acquisition process, several light fields are captured at varying exposures with a plenoptic camera. The RAW data is de-multiplexed to retrieve all light field viewpoints for each exposure and perform a soft detection of saturated pixels. Considering a matrix which concatenates all the vector-ized views, we formulate the problem of recovering saturated areas as a Weighted Low Rank Approximation (WLRA) where the weights are defined from the soft saturation detection. We show that our algorithm successfully recovers the parallax in the overexposed areas while the Truncated Nuclear Norm (TNN) minimization, traditionally used for single view HDR imaging, does not generalize to light fields. Advantages of our weighted approach as well as the simultaneous processing of all the viewpoints are also demonstrated in our experiments.

Mots clés: Weighted Low Rank Approximation; Low Rank Matrix Completion; Light Fields; High Dynamic Range (HDR)

Domaines: Traitement du signal et de l'image [eess.SP]

Mikaël Le Pendu, Aljosa Smolic, Christine Guillemot. High dynamic range light fields via weighted low rank approximation. ICIP 2018 - IEEE International Conference on Image Processing, Oct 2018, Athens, Greece. pp.1-5, ⟨10.1109/ICIP.2018.8451584⟩. ⟨hal-01872277⟩