\documentclass{beamer} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage[english]{babel} %\usepackage{paralist} %\useoutertheme{infolines} \usepackage{graphicx} \usepackage{hyperref} \usepackage{listings} \usepackage{color} \usepackage{textcomp} \usepackage{csquotes} \usetheme{Warsaw} \usecolortheme{crane} \pagenumbering{arabic} \def\thesection{\arabic{section})} \def\thesubsection{\alph{subsection})} \def\thesubsubsection{(\roman{subsubsection})} \setbeamertemplate{navigation symbols}{} \graphicspath{ {src/} {/home/jim/Pictures/} } \definecolor{mygreen}{rgb}{0,0.6,0} \definecolor{mygray}{rgb}{0.5,0.5,0.5} \definecolor{mymauve}{rgb}{0.58,0,0.82} \usepackage[ backend=biber, bibstyle=authoryear, citestyle=authoryear, minnames=1, maxnames=2 ]{biblatex} \addbibresource{ma.bib} \MakeOuterQuote{"} %\definecolor{craneorange}{RGB}{61,61,61} %\definecolor{craneblue}{RGB}{255,255,255} \lstset{ % backgroundcolor=\color{white}, % choose the background color; you must add \usepackage{color} or \usepackage{xcolor} basicstyle=\footnotesize, % the size of the fonts that are used for the code breakatwhitespace=false, % sets if automatic breaks should only happen at whitespace breaklines=true, % sets automatic line breaking captionpos=b, % sets the caption-position to bottom commentstyle=\color{mygray}, % comment style deletekeywords={}, % if you want to delete keywords from the given language escapeinside={\%*}{*)}, % if you want to add LaTeX within your code extendedchars=true, % lets you use non-ASCII characters; for 8-bits encodings only, does not work with UTF-8 keepspaces=true, % keeps spaces in text, useful for keeping indentation of code (possibly needs columns=flexible) keywordstyle=\color{blue}, % keyword style language=PHP, % the language of the code morekeywords={class, function, return, protected, public, private, const, static, new, extends, namespace, null}, % if you want to add more keywords to the set numbers=left, % where to put the line-numbers; possible values are (none, left, right) numbersep=5pt, % how far the line-numbers are from the code numberstyle=\tiny\color{mygray}, % the style that is used for the line-numbers rulecolor=\color{black}, % if not set, the frame-color may be changed on line-breaks within not-black text (e.g. comments (green here)) showspaces=false, % show spaces everywhere adding particular underscores; it overrides 'showstringspaces' showstringspaces=false, % underline spaces within strings only showtabs=false, % show tabs within strings adding particular underscores stepnumber=2, % the step between two line-numbers. If it's 1, each line will be numbered stringstyle=\color{mygreen}, % string literal style tabsize=2, % sets default tabsize to 2 spaces title=\lstname % show the filename of files included with \lstinputlisting; also try caption instead of title } \hypersetup{ pdfauthor=Jim Martens, pdfstartview=Fit } \expandafter\def\expandafter\insertshorttitle\expandafter{% \raggedleft \insertframenumber\,/\,\inserttotalframenumber\;} \begin{document} \author{Jim 2martens} \title{Novelty detection for object detection in open set conditions} \date{October 18th, 2019} \begin{frame} \titlepage \end{frame} \begin{frame}{Contents} \tableofcontents \end{frame} \section{Motivation} \begin{frame}{Problem} \begin{itemize} \item network trained with one set of objects \vfill \item encounters other objects in reality \vfill \item cannot properly classify or detect unknown object types \end{itemize} \end{frame} \begin{frame}{Open Set} \centering \begin{figure}[h] \includegraphics[scale=0.8]{images/open-set.pdf} \caption{Open set problem: test set contains classes that were not present during training. Resembles figure 1 of \cite{Miller2018}} \end{figure} \end{frame} \begin{frame}{Approaches} \begin{itemize} \item somehow detect or identify novel input \vfill \item \cite{Pimentel2014} provide overview of different approaches \vfill \item will look at reconstruction-based novelty detection \vfill \item in particular, dropout sampling \end{itemize} \end{frame} \begin{frame}{Hypothesis} \centering Dropout sampling delivers better object detection performance under open set conditions compared to object detection without it. \end{frame} \section{Background} \begin{frame}{Related Works} \begin{itemize} \item Bayesian networks can be used to model uncertainty (\cite{Ghahramani2015}) \vfill \item \cite{Gal2017} shows that dropout training resembles a general approximate Bayesian model \vfill \item \cite{Teye2018} argue that most modern networks have adopted other regularisation techniques \vfill \item \cite{Ioffe2015} introduce batch normalisation \end{itemize} \end{frame} \section{Methods} \subsection{Structure} \begin{frame}{Vanilla SSD} \centering \begin{figure}[h] \includegraphics{images/vanilla-ssd.pdf} \caption{Vanilla SSD network as defined by \cite{Liu2016}} \end{figure} \begin{itemize} \item detects objects of differing sizes \end{itemize} \end{frame} \begin{frame}{Bayesian SSD} \centering \begin{figure}[h] \includegraphics[scale=0.95]{images/bayesian-ssd.pdf} \caption{Bayesian SSD network as defined by \cite{Miller2018}} \end{figure} \begin{itemize} \item adds dropout layers and multiple forward passes \end{itemize} \end{frame} \subsection{Decoding Pipelines} \begin{frame}{Vanilla SSD} \begin{enumerate} \item (batch\_size, \#nr\_boxes, \#nr\_classes + 12) \vfill \item transforming relative into absolute coordinates \vfill \item per-class confidence threshold \vfill \item per-class non-maximum suppression \vfill \item top \(k\) \end{enumerate} \end{frame} \begin{frame}{Vanilla SSD with Entropy Threshold} \begin{enumerate} \item (batch\_size, \#nr\_boxes, \#nr\_classes + 12) \vfill \item transforming relative into absolute coordinates \vfill \item \textbf{entropy thresholding} \vfill \item per-class confidence threshold \vfill \item per-class non-maximum suppression \vfill \item top \(k\) \end{enumerate} \end{frame} \begin{frame}{Bayesian SSD} \begin{enumerate} \item (batch\_size, \#nr\_boxes \(\cdot\) \#nr\_forward\_passes, \#nr\_classes + 12) \vfill \item transforming relative into absolute coordinates \vfill \item confidence threshold for class with highest confidence \vfill \item discard predictions with background 0.8 or higher \vfill \item partition into observations \vfill \item entropy thresholding \vfill \item per-class confidence threshold \vfill \item per-class non-maximum suppression \vfill \item top \(k\) \end{enumerate} \end{frame} \section{Results and Interpretation} \subsection{Data} \begin{frame}{MS COCO} \begin{table}[htbp] \centering \begin{tabular}{rcc} \hline class & number of & percentage of \\ & detections & total \\ \hline total & 31,991 & 100\% \\ persons & 10,988 & 34.3\% \\ cars & 1,932 & 6\% \\ chairs & 1,791 & 5.6\% \\ bottles & 1,021 & 3.2\% \\ cups & 898 & 2.8\% \\ \hline \end{tabular} \caption{Number of ground truth detections per class (top 5).} \end{table} \end{frame} \subsection{Results} \begin{frame}[allowframebreaks]{Micro Averaging} \begin{table}[ht] \begin{tabular}{rcccc} \hline & max & abs OSE & Recall & Precision\\ & \(F_1\) Score & \multicolumn{3}{c}{at max \(F_1\) point} \\ \hline 0.01 conf & 0.255 & 3176 & 0.214 & 0.318 \\ 0.2 conf & \textbf{0.376} & 2939 & \textbf{0.382} & 0.372 \\ entropy - 0.01 conf & 0.255 & 3168 & 0.214 & 0.318 \\ % entropy} thresh: 2.4 for vanilla} SSD} is best \hline \end{tabular} \caption{Vanilla SSD rounded results for micro averaging.} \end{table} \begin{table}[ht] \begin{tabular}{rcccc} \hline & max & abs OSE & Recall & Precision\\ & \(F_1\) Score & \multicolumn{3}{c}{at max \(F_1\) point} \\ \hline no DO - 0.2 conf & 0.209 & 2709 & 0.300 & 0.161 \\ no DO - 0.2 conf - NMS& 0.371 & \textbf{2335} & 0.365 & \textbf{0.378} \\ 0.9 keep - 0.2 conf - NMS & 0.359 & 2584 & 0.363 & 0.357 \\ 0.5 keep - 0.2 conf - NMS & 0.325 & 2759 & 0.342 & 0.311 \\ \hline \end{tabular} \caption{Bayesian SSD rounded results for micro averaging. All variants use 10 forward passes.} \end{table} \end{frame} \begin{frame}[allowframebreaks]{Macro Averaging} \begin{table}[ht] \begin{tabular}{rcccc} \hline & max & abs OSE & Recall & Precision\\ & \(F_1\) Score & \multicolumn{3}{c}{at max \(F_1\) point} \\ \hline 0.01 conf & 0.370 & 1426 & 0.328 & 0.424 \\ 0.2 conf & \textbf{0.375} & 1218 & \textbf{0.338} & 0.424 \\ entropy - 0.01 conf & 0.370 & 1373 & 0.329 & \textbf{0.425} \\ \hline \end{tabular} \caption{Vanilla SSD rounded results for macro averaging.} \end{table} \begin{table}[ht] \begin{tabular}{rcccc} \hline & max & abs OSE & Recall & Precision\\ & \(F_1\) Score & \multicolumn{3}{c}{at max \(F_1\) point} \\ \hline no DO - 0.2 conf & 0.226 & \textbf{809} & 0.229 & 0.224 \\ no DO - 0.2 conf - NMS & 0.363 & 1057 & 0.321 & 0.420 \\ 0.9 keep - 0.2 conf - NMS & 0.355 & 1137 & 0.320 & 0.399 \\ 0.5 keep - 0.2 conf - NMS & 0.322 & 1264 & 0.307 & 0.340 \\ \hline \end{tabular} \caption{Bayesian SSD rounded results for macro averaging. All variants use 10 forward passes.} \end{table} \end{frame} \begin{frame}{Example: Vanilla SSD} \centering \begin{figure}[h] \includegraphics[width=\textwidth]{images/COCO_val2014_000000336587_bboxes_vanilla.png} \end{figure} \end{frame} \begin{frame}{Example: Bayesian SSD 0.9 keep ratio} \centering \begin{figure}[h] \includegraphics[width=\textwidth]{images/COCO_val2014_000000336587_bboxes_bayesian.png} \end{figure} \end{frame} \subsection{Interpretation} \begin{frame}[allowframebreaks]{Effect of NMS} \begin{table}[tbp] \centering \begin{tabular}{rccc} \hline variant & before & after & after \\ & entropy/NMS & entropy/NMS & top \(k\) \\ \hline no DO, no NMS & 155,251 & 122,868 & 72,207 \\ no DO, NMS & 155,250 & 36,061 & 33,827 \\ \hline \end{tabular} \caption{Comparison of Bayesian SSD variants without dropout with respect to the number of detections before the entropy threshold, after it and/or NMS, and after top \(k\). The entropy threshold 1.5 was used for both.} \end{table} \begin{table}[htbp] \centering \begin{tabular}{rccc} \hline variant & before & after & after \\ & entropy/NMS & entropy/NMS & top \(k\) \\ \hline no DO, no NMS & 19,014 & 48,484 & 27,707 \\ no DO, NMS & 19,014 & 14,542 & 13,486 \\ \hline \end{tabular} \caption{Comparison of Bayesian SSD variants without dropout with respect to the number of detections before the entropy threshold, after it and/or NMS, and after top \(k\). The entropy threshold 1.5 was used for both. The numbers are for the persons class.} \end{table} \begin{table}[htbp] \centering \begin{tabular}{rccc} \hline variant & before & after & after \\ & entropy/NMS & entropy/NMS & top \(k\) \\ \hline no DO, no NMS & 1,011 & 1,785 & 1,458 \\ no DO, NMS & 1,011 & 426 & 425 \\ \hline \end{tabular} \caption{Comparison of Bayesian SSD variants without dropout with respect to the number of detections before the entropy threshold, after it and/or NMS, and after top \(k\). The entropy threshold 1.5 was used for both. The numbers are for the dogs class.} \end{table} \end{frame} \begin{frame}{Effect of Dropout on Observations} \begin{table}[tbp] \centering \begin{tabular}{rccc} \hline variant & after & after \\ & prediction & observation grouping \\ \hline no DO, NMS & 1,677,050 & 155,250 \\ keep rate 0.9, NMS & 1,617,675 & 549,166 \\ \hline \end{tabular} \caption{Comparison of Bayesian SSD variants without dropout and with 0.9 keep ratio of dropout with respect to the number of detections directly after the network predictions and after the observation grouping.} \end{table} \end{frame} \begin{frame}{Conclusion} \begin{itemize} \item hypothesis was not confirmed \vfill \item worse performance than according to \cite{Miller2018} \vfill \item reason for difference should be investigated \end{itemize} \end{frame} \begin{frame}{Questions} \centering Time for questions! \end{frame} \begin{frame}[t,allowframebreaks]{References} \printbibliography \end{frame} \end{document}