673 research outputs found
Neural Illumination: Lighting Prediction for Indoor Environments
This paper addresses the task of estimating the light arriving from all
directions to a 3D point observed at a selected pixel in an RGB image. This
task is challenging because it requires predicting a mapping from a partial
scene observation by a camera to a complete illumination map for a selected
position, which depends on the 3D location of the selection, the distribution
of unobserved light sources, the occlusions caused by scene geometry, etc.
Previous methods attempt to learn this complex mapping directly using a single
black-box neural network, which often fails to estimate high-frequency lighting
details for scenes with complicated 3D geometry. Instead, we propose "Neural
Illumination" a new approach that decomposes illumination prediction into
several simpler differentiable sub-tasks: 1) geometry estimation, 2) scene
completion, and 3) LDR-to-HDR estimation. The advantage of this approach is
that the sub-tasks are relatively easy to learn and can be trained with direct
supervision, while the whole pipeline is fully differentiable and can be
fine-tuned with end-to-end supervision. Experiments show that our approach
performs significantly better quantitatively and qualitatively than prior work
Joint Material and Illumination Estimation from Photo Sets in the Wild
Faithful manipulation of shape, material, and illumination in 2D Internet
images would greatly benefit from a reliable factorization of appearance into
material (i.e., diffuse and specular) and illumination (i.e., environment
maps). On the one hand, current methods that produce very high fidelity
results, typically require controlled settings, expensive devices, or
significant manual effort. To the other hand, methods that are automatic and
work on 'in the wild' Internet images, often extract only low-frequency
lighting or diffuse materials. In this work, we propose to make use of a set of
photographs in order to jointly estimate the non-diffuse materials and sharp
lighting in an uncontrolled setting. Our key observation is that seeing
multiple instances of the same material under different illumination (i.e.,
environment), and different materials under the same illumination provide
valuable constraints that can be exploited to yield a high-quality solution
(i.e., specular materials and environment illumination) for all the observed
materials and environments. Similar constraints also arise when observing
multiple materials in a single environment, or a single material across
multiple environments. The core of this approach is an optimization procedure
that uses two neural networks that are trained on synthetic images to predict
good gradients in parametric space given observation of reflected light. We
evaluate our method on a range of synthetic and real examples to generate
high-quality estimates, qualitatively compare our results against
state-of-the-art alternatives via a user study, and demonstrate
photo-consistent image manipulation that is otherwise very challenging to
achieve
What Is Around The Camera?
How much does a single image reveal about the environment it was taken in? In
this paper, we investigate how much of that information can be retrieved from a
foreground object, combined with the background (i.e. the visible part of the
environment). Assuming it is not perfectly diffuse, the foreground object acts
as a complexly shaped and far-from-perfect mirror. An additional challenge is
that its appearance confounds the light coming from the environment with the
unknown materials it is made of. We propose a learning-based approach to
predict the environment from multiple reflectance maps that are computed from
approximate surface normals. The proposed method allows us to jointly model the
statistics of environments and material properties. We train our system from
synthesized training data, but demonstrate its applicability to real-world
data. Interestingly, our analysis shows that the information obtained from
objects made out of multiple materials often is complementary and leads to
better performance.Comment: Accepted to ICCV. Project:
http://homes.esat.kuleuven.be/~sgeorgou/multinatillum
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