4,249 research outputs found
Defocus Image Deblurring Network with Defocus Map Estimation as Auxiliary Task
Different from the object motion blur, the defocus blur is caused by the limitation of the cameras’ depth of field. The defocus amount can be characterized by the parameter of point spread function and thus forms a defocus map. In this paper, we propose a new network architecture called Defocus Image Deblurring Auxiliary Learning Net (DID-ANet), which is specifically designed for single image defocus deblurring by using defocus map estimation as auxiliary task to improve the deblurring result. To facilitate the training of the network, we build a novel and large-scale dataset for single image defocus deblurring, which contains the defocus images, the defocus maps and the all-sharp images. To the best of our knowledge, the new dataset is the first large-scale defocus deblurring dataset for training deep networks. Moreover, the experimental results demonstrate that the proposed DID-ANet outperforms the state-of-the-art methods for both tasks of defocus image deblurring and defocus map estimation, both quantitatively and qualitatively. The dataset, code, and model is available on GitHub: https://github.com/xytmhy/DID-ANet-Defocus-Deblurring
Focusing on out-of-focus : assessing defocus estimation algorithms for the benefit of automated image masking
Acquiring photographs as input for an image-based modelling pipeline is less trivial than often assumed. Photographs should be correctly exposed, cover the subject sufficiently from all possible angles, have the required spatial resolution, be devoid of any motion blur, exhibit accurate focus and feature an adequate depth of field. The last four characteristics all determine the " sharpness " of an image and the photogrammetric, computer vision and hybrid photogrammetric computer vision communities all assume that the object to be modelled is depicted " acceptably " sharp throughout the whole image collection. Although none of these three fields has ever properly quantified " acceptably sharp " , it is more or less standard practice to mask those image portions that appear to be unsharp due to the limited depth of field around the plane of focus (whether this means blurry object parts or completely out-of-focus backgrounds). This paper will assess how well-or ill-suited defocus estimating algorithms are for automatically masking a series of photographs, since this could speed up modelling pipelines with many hundreds or thousands of photographs. To that end, the paper uses five different real-world datasets and compares the output of three state-of-the-art edge-based defocus estimators. Afterwards, critical comments and plans for the future finalise this paper
Aperture Supervision for Monocular Depth Estimation
We present a novel method to train machine learning algorithms to estimate
scene depths from a single image, by using the information provided by a
camera's aperture as supervision. Prior works use a depth sensor's outputs or
images of the same scene from alternate viewpoints as supervision, while our
method instead uses images from the same viewpoint taken with a varying camera
aperture. To enable learning algorithms to use aperture effects as supervision,
we introduce two differentiable aperture rendering functions that use the input
image and predicted depths to simulate the depth-of-field effects caused by
real camera apertures. We train a monocular depth estimation network end-to-end
to predict the scene depths that best explain these finite aperture images as
defocus-blurred renderings of the input all-in-focus image.Comment: To appear at CVPR 2018 (updated to camera ready version
Depth Estimation and Image Restoration by Deep Learning from Defocused Images
Monocular depth estimation and image deblurring are two fundamental tasks in
computer vision, given their crucial role in understanding 3D scenes.
Performing any of them by relying on a single image is an ill-posed problem.
The recent advances in the field of Deep Convolutional Neural Networks (DNNs)
have revolutionized many tasks in computer vision, including depth estimation
and image deblurring. When it comes to using defocused images, the depth
estimation and the recovery of the All-in-Focus (Aif) image become related
problems due to defocus physics. Despite this, most of the existing models
treat them separately. There are, however, recent models that solve these
problems simultaneously by concatenating two networks in a sequence to first
estimate the depth or defocus map and then reconstruct the focused image based
on it. We propose a DNN that solves the depth estimation and image deblurring
in parallel. Our Two-headed Depth Estimation and Deblurring Network (2HDED:NET)
extends a conventional Depth from Defocus (DFD) networks with a deblurring
branch that shares the same encoder as the depth branch. The proposed method
has been successfully tested on two benchmarks, one for indoor and the other
for outdoor scenes: NYU-v2 and Make3D. Extensive experiments with 2HDED:NET on
these benchmarks have demonstrated superior or close performances to those of
the state-of-the-art models for depth estimation and image deblurring
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