1,093 research outputs found
Perspective Plane Program Induction from a Single Image
We study the inverse graphics problem of inferring a holistic representation
for natural images. Given an input image, our goal is to induce a
neuro-symbolic, program-like representation that jointly models camera poses,
object locations, and global scene structures. Such high-level, holistic scene
representations further facilitate low-level image manipulation tasks such as
inpainting. We formulate this problem as jointly finding the camera pose and
scene structure that best describe the input image. The benefits of such joint
inference are two-fold: scene regularity serves as a new cue for perspective
correction, and in turn, correct perspective correction leads to a simplified
scene structure, similar to how the correct shape leads to the most regular
texture in shape from texture. Our proposed framework, Perspective Plane
Program Induction (P3I), combines search-based and gradient-based algorithms to
efficiently solve the problem. P3I outperforms a set of baselines on a
collection of Internet images, across tasks including camera pose estimation,
global structure inference, and down-stream image manipulation tasks.Comment: CVPR 2020. First two authors contributed equally. Project page:
http://p3i.csail.mit.edu
Single Image Human Proxemics Estimation for Visual Social Distancing
In this work, we address the problem of estimating the so-called "Social
Distancing" given a single uncalibrated image in unconstrained scenarios. Our
approach proposes a semi-automatic solution to approximate the homography
matrix between the scene ground and image plane. With the estimated homography,
we then leverage an off-the-shelf pose detector to detect body poses on the
image and to reason upon their inter-personal distances using the length of
their body-parts. Inter-personal distances are further locally inspected to
detect possible violations of the social distancing rules. We validate our
proposed method quantitatively and qualitatively against baselines on public
domain datasets for which we provided groundtruth on inter-personal distances.
Besides, we demonstrate the application of our method deployed in a real
testing scenario where statistics on the inter-personal distances are currently
used to improve the safety in a critical environment.Comment: Paper accepted at WACV 2021 conferenc
3D object reconstruction using computer vision : reconstruction and characterization applications for external human anatomical structures
Tese de doutoramento. Engenharia Informática. Faculdade de Engenharia. Universidade do Porto. 201
Biometric fusion methods for adaptive face recognition in computer vision
PhD ThesisFace recognition is a biometric method that uses different techniques to identify the individuals based on the facial information received from digital image data. The system of face recognition is widely used for security purposes, which has challenging problems. The solutions to some of the most important challenges are proposed in this study. The aim of this thesis is to investigate face recognition across pose problem based on the image parameters of camera calibration. In this thesis, three novel methods have been derived to address the challenges of face recognition and offer solutions to infer the camera parameters from images using a geomtric approach based on perspective projection. The following techniques were used: camera calibration CMT and Face Quadtree Decomposition (FQD), in order to develop the face camera measurement technique (FCMT) for human facial recognition.
Facial information from a feature extraction and identity-matching algorithm has been created. The success and efficacy of the proposed algorithm are analysed in terms of robustness to noise, the accuracy of distance measurement, and face recognition. To overcome the intrinsic and extrinsic parameters of camera calibration parameters, a novel technique has been developed based on perspective projection, which uses different geometrical shapes to calibrate the camera. The parameters used in novel measurement technique CMT that enables the system to infer the real distance for regular and irregular objects from the 2-D images. The proposed system of CMT feeds into FQD to measure the distance between the facial points. Quadtree decomposition enhances the representation of edges and other singularities along curves of the face, and thus improves directional features from face detection across face pose. The proposed FCMT system is the new combination of CMT and FQD to recognise the faces in the various pose.
The theoretical foundation of the proposed solutions has been thoroughly developed and discussed in detail. The results show that the proposed algorithms outperform existing algorithms in face recognition, with a 2.5% improvement in main error recognition rate compared with recent studies
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