# Codebooks

## K-means codebook 

A common technique for codebook generation involves utilising K-means clustering on a sample of the
image descriptors. In this way descriptors may be mapped to *visual* words which lend themselves to
binning and therefore the creation of bag-of-words histograms for the use of classification.

In this courseworok 100-thousand descriptors have been selected to build the visual vocabulary from the
Caltech dataset.

## Vocabulary size 

The number of clusters or the number of centroids determine the vocabulary size.

![Bag-of-words Training histogram](fig/km-histogram.pdf)
![Bag-of-words Testing histogram](fig/km-histtest.pdf)

## Bag-of-words histograms of example training/testing images

## Vector quantisation process

# RF classifier 

Train and test Random Forest using the training and testing data set in the form of bag-of-words
obtained in Q1. Change the RF parameters (including the number of trees, the depth of trees, the
degree of randomness parameter, the type of weak-learners: e.g. axis-aligned or two-pixel test),
and show and discuss the results:

## recognition accuracy, confusion matrix,

## example success/failures,

## time-efficiency of training/testing, 

## impact of the vocabulary size on classification accuracy. 

# RF codebook

In Q1, replace the K-means with the random forest codebook, i.e. applying RF to 128 dimensional
descriptor vectors with their image category labels, and using the RF leaves as the visual
vocabulary. With the bag-of-words representations of images obtained by the RF codebook, train
and test Random Forest classifier similar to Q2. Try different parameters of the RF codebook and
RF classifier, and show/discuss the results in comparison with the results of Q2, including the
vector quantisation complexity. 

# Pictures

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/256t1_e200D5_cm.pdf}
\caption{Part 3 confusion matrix e100k256d5cm}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/Depth_Trees_P2.pdf}
\caption{DepthTreesP2}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/Depth_Trees_P3.pdf}
\caption{DepthTreesP3}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/Depth_Trees_P3_fixedestimators.pdf}
\caption{DepthTreesP3fixedestimators}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/e100k256d5_cm.pdf}
\caption{e100k256d5cm Kmean Confusion Matrix}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/error_depth_kmean100.pdf}
\caption{errordepthkmean100}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/error_depth_p3.pdf}
\caption{errordepthp3}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/kmean_rand.pdf}
\caption{kmeanrand}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/kmeans_vocsize.pdf}
\caption{kmeansvocsize}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/new_kmean_random.pdf}
\caption{newkmeanrandom}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/p3_colormap.pdf}
\caption{p3colormap}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/p3_rand.pdf}
\caption{p3rand}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/p3_time.pdf}
\caption{p3time}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/p3_vocsize.pdf}
\caption{p3vocsize}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/time_kmeans.pdf}
\caption{timekmeans}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/trees_kmean.pdf}
\caption{treeskmean}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=18em]{fig/trees_p3.pdf}
\caption{treesp3}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=10em]{fig/success_km.pdf}
\includegraphics[width=10em]{fig/fail_km.pdf}
\caption{Kmean: Success on the left; Failure on the right}
\label{fig:rerank}
\end{center}
\end{figure}

\begin{figure}[H]
\begin{center}
\includegraphics[width=10em]{fig/success_3.pdf}
\includegraphics[width=10em]{fig/fail_3.pdf}
\caption{Part3: Success on the left; Failure on the right}
\label{fig:rerank}
\end{center}
\end{figure}

# References