5 research outputs found
Structure evaluation of computer human animation quality
The University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of PhilosophyThis work will give a wide survey for various techniques that are present in the field of character computer animation, which concentrates particularly on those techniques and problems involved in the production of realistic character synthesis and motion. A preliminary user study (including Questionnaire, online publishing such as flicker.com, interview, multiple choice questions, publishing on Android mobile phone, and questionnaire analysis, validation, statistical evaluation, design steps and Character Animation Observation) was conducted to explore design questions, identify users' needs, and obtain a "true story" of quality character animation and the effect of using animation as useful tools in Education.
The first set of questionnaires were designed to accommodate the evaluation of animation from candidates from different walks of life, ranging from animators, gamers, teacher assistances (TA), students, teaches, professionals and researchers using and evaluating pre-prepared animated character videos scenarios, and the study outcomes has reviewed the recent advances techniques of character animation, motion editing that enable the control of complex animations by interactively blending, improving and tuning artificial or captured motions.
The goal of this work was to augment the students learning intuition by providing ways to make education and learning more interesting, useful and fun objectively, in order to improve students’ respond and understanding to any subject area through the use of animation also by producing the required high quality motion, reaction, interaction and story board to viewers of the motion.
We present a variety of different evaluation to the motion quality by measuring user sensitivity, observations to any noticeable artefact, usability, usefulness etc. to derive clear useful guidelines from the results, and discuss several interesting systematic trends we have uncovered in the experimental data. We also present an efficient technique for evaluating the capability of animation influence on education to fulfil the requirements of a given scenario, along with the advantages and the effect on those deficiencies of some methods commonly used to improve animation quality to serve the learning process. Finally, we propose a wide range of extensions and statistical calculation enabled by these evaluation tools, such as Wilcoxon, F-test, T-test, Wondershare Quiz creator (WQC), Chi square and many others explained with full details
Closing the Loop on Runtime Monitors with Fallback-Safe MPC
When we rely on deep-learned models for robotic perception, we must recognize
that these models may behave unreliably on inputs dissimilar from the training
data, compromising the closed-loop system's safety. This raises fundamental
questions on how we can assess confidence in perception systems and to what
extent we can take safety-preserving actions when external environmental
changes degrade our perception model's performance. Therefore, we present a
framework to certify the safety of a perception-enabled system deployed in
novel contexts. To do so, we leverage robust model predictive control (MPC) to
control the system using the perception estimates while maintaining the
feasibility of a safety-preserving fallback plan that does not rely on the
perception system. In addition, we calibrate a runtime monitor using recently
proposed conformal prediction techniques to certifiably detect when the
perception system degrades beyond the tolerance of the MPC controller,
resulting in an end-to-end safety assurance. We show that this control
framework and calibration technique allows us to certify the system's safety
with orders of magnitudes fewer samples than required to retrain the perception
network when we deploy in a novel context on a photo-realistic aircraft taxiing
simulator. Furthermore, we illustrate the safety-preserving behavior of the MPC
on simulated examples of a quadrotor. We open-source our simulation platform
and provide videos of our results at our project page:
https://tinyurl.com/fallback-safe-mpc.Comment: Accepted to the 2023 IEEE Conference on Decision and Contro
IMAGE BASED MODELING FROM SPHERICAL PHOTOGRAMMETRY AND STRUCTURE FOR MOTION. THE CASE OF THE TREASURY, NABATEAN ARCHITECTURE IN PETRA
This research deals with an efficient and low cost methodology to obtain a metric and photorealstic survey of a complex architecture. Photomodeling is an already tested interactive approach to produce a detailed and quick 3D model reconstruction. Photomodeling goes along with the creation of a rough surface over which oriented images can be back-projected in real time. Lastly the model can be enhanced checking the coincidence between the surface and the projected texture. The challenge of this research is to combine the advantages of two technologies already set up and used in many projects: spherical photogrammetry (Fangi, 2007,2008,2009,2010) and structure for motion (Photosynth web service and Bundler + CMVS2 + PMVS2). The input images are taken from the same points of view to form the set of panoramic photos paying attention to use well-suited projections: equirectangular for spherical photogrammetry and rectilinear for Photosynth web service. The performance of the spherical photogrammetry is already known in terms of its metric accuracy and acquisition quickness but time is required in the restitution step because of the manual homologous point recognition from different panoramas. In Photosynth instead the restitution is quick and automated: the provided point clouds are useful benchmarks to start with the model reconstruction even if lacking in details and scale. The proposed workflow needs of ad-hoc tools to capture high resolution rectilinear panoramic images and visualize Photosynth point clouds and orientation camera parameters. All of them are developed in VVVV programming environment. 3DStudio Max environment is then chosen because of its performance in terms of interactive modeling, UV mapping parameters handling and real time visualization of projected texture on the model surface. Experimental results show how is possible to obtain a 3D photorealistic model using the scale of the spherical photogrammetry restitution to orient web provided point clouds. Moreover the proposed research highlights how is possible to speed up the model reconstruction without losing metric and photometric accuracy. In the same time, using the same panorama dataset, it picks out a useful chance to compare the orientations coming from the two mentioned technologies (Spherical Photogrammetry and Structure for Motion)
Image Based Modeling from Spherical Photogrammetry and Structure for Motion. The Case of the Treasury, Nabatean Architecture in Petra
This research deals with an efficient and low cost methodology to obtain a metric and photorealstic survey of a complex architecture. Photomodeling is an already tested interactive approach to produce a detailed and quick 3D model reconstruction. Photomodeling goes along with the creation of a rough surface over which oriented images can be back-projected in real time. Lastly the model can be enhanced checking the coincidence between the surface and the projected texture. The challenge of this research is to combine the advantages of two technologies already set up and used in many projects: spherical photogrammetry (Fangi, 2007,2008,2009,2010) and structure for motion (Photosynth web service and Bundler + CMVS2 + PMVS2). The input images are taken from the same points of view to form the set of panoramic photos paying attention to use well-suited projections: equirectangular for spherical photogrammetry and rectilinear for Photosynth web service. The performance of the spherical photogrammetry is already known in terms of its metric accuracy and acquisition quickness but time is required in the restitution step because of the manual homologous point recognition from different panoramas. In Photosynth instead the restitution is quick and automated: the provided point clouds are useful benchmarks to start with the model reconstruction even if lacking in details and scale. The proposed workflow needs of ad-hoc tools to capture high resolution rectilinear panoramic images and visualize Photosynth point clouds and orientation camera parameters. All of them are developed in VVVV programming environment. 3DStudio Max environment is then chosen because of its performance in terms of interactive modeling, UV mapping parameters handling and real time visualization of projected texture on the model surface. Experimental results show how is possible to obtain a 3D photorealistic model using the scale of the spherical photogrammetry restitution to orient web provided point clouds. Moreover the proposed research highlights how is possible to speed up the model reconstruction without losing metric and photometric accuracy. In the same time, using the same panorama dataset, it picks out a useful chance to compare the orientations coming from the two mentioned technologies (Spherical Photogrammetry and Structure for Motion)
Diffusion Model Alignment Using Direct Preference Optimization
Large language models (LLMs) are fine-tuned using human comparison data with
Reinforcement Learning from Human Feedback (RLHF) methods to make them better
aligned with users' preferences. In contrast to LLMs, human preference learning
has not been widely explored in text-to-image diffusion models; the best
existing approach is to fine-tune a pretrained model using carefully curated
high quality images and captions to improve visual appeal and text alignment.
We propose Diffusion-DPO, a method to align diffusion models to human
preferences by directly optimizing on human comparison data. Diffusion-DPO is
adapted from the recently developed Direct Preference Optimization (DPO), a
simpler alternative to RLHF which directly optimizes a policy that best
satisfies human preferences under a classification objective. We re-formulate
DPO to account for a diffusion model notion of likelihood, utilizing the
evidence lower bound to derive a differentiable objective. Using the Pick-a-Pic
dataset of 851K crowdsourced pairwise preferences, we fine-tune the base model
of the state-of-the-art Stable Diffusion XL (SDXL)-1.0 model with
Diffusion-DPO. Our fine-tuned base model significantly outperforms both base
SDXL-1.0 and the larger SDXL-1.0 model consisting of an additional refinement
model in human evaluation, improving visual appeal and prompt alignment. We
also develop a variant that uses AI feedback and has comparable performance to
training on human preferences, opening the door for scaling of diffusion model
alignment methods