Commit changes to Chapter 1-3

021_VideoCoding/VideoCodingReview.tex

@@ -3,7 +3,7 @@
 \renewcommand{\FigsPath}{./021_VideoCoding/Figures}
 
 % \chapter{\HIGHLIGHT{The \ac{hevc}  Standard}}
-\chapter[The High Efficiency Video Coding Standard]{The High Efficiency Video \\Coding Standard}
+\chapter{The High Efficiency Video Coding Standard \VERSION{1}}
 %\chapter{\HIGHLIGHT{The State-of-Art Video Coding}}
 \label{Chapter:HEVCReview}
 
@@ -351,22 +351,27 @@ To re-use the same context in the whole slice (or tile) each row requires a dela
 \section{Data structures}
 \label{Section2:CodingStructures}
 
-\begin{figure}[!t]
-    \centering
-    \input{\FigsPath/BlockPartitionsWithTree.tikz}
-    \caption{Representation of a CTU ($64\times64$) and its partitioning into CUs and PUs (left); corresponding quad-tree with coding order (right)}
-    \label{Figure2:HEVCCodingStructure}
-\end{figure}
-
 Despite the fact that the \ac{hevc} standard follows a traditional hybrid video coding architecture, it introduces significant changes in the data structures when compared to the previous standards (e.g., \ac{h264}).
-In \ac{h264} each frame is divided into units so-called \acs{mb}, which are composed by a $16\times16$ block of luma samples and two $8\times8$ blocks of chroma samples, assuming video data in YUV 4:2:0 sub-sampling. The \ac{mb} is considered the basic processing unit in the \ac{h264}, and the respective coding mode define whether the corresponding pixels are coded as intra or intra prediction. Each \ac{mb} could also be partitioned into sub-blocks which should follow the same prediction mode.
+In \ac{h264} each frame is divided into units so-called \acs{mb}, which are composed by a $16\times16$ block of luma samples and two $8\times8$ blocks of chroma samples, assuming video data in YUV 4:2:0 sub-sampling. The \ac{mb} is considered the basic processing unit in the \ac{h264}, and the respective coding mode define whether the corresponding pixels are coded as intra or intra prediction. 
+Each \ac{mb} could also be partitioned into sub-blocks which should follow the same prediction mode.
 
 
 \glsreset{ctu}
 \glsreset{cu}
 
-The basic data structures in \ac{hevc} are quite different from \ac{h264}. Each picture is divided into blocks named as \ac{ctu}~\cite{BlockPartHEVC2012}. The maximum \ac{ctu} size is an encoder configuration parameter and signalled to the decoder, and should be one of the following:  $64\times64$,  $32\times32$ and $16\times16$. The use of data structures with larger size in \ac{hevc} was adopted to achieve higher coding efficiency especially in high resolution video. Each \ac{ctu} can be recursively partitioned into four smaller units, referred to as \acs{cu}, until it reaches the minimum unit size, which cannot be smaller than to $8\times8$ pixels. Similar to the maximum \ac{ctu} size, the minimum size is also defined at the encoding time.
+The basic data structures in \ac{hevc} are quite different from \ac{h264}. Each picture is divided into blocks named as \ac{ctu}~\cite{BlockPartHEVC2012}. The maximum \ac{ctu} size is an encoder configuration parameter and signalled to the decoder, and should be one of the following:  $64\times64$,  $32\times32$ and $16\times16$. The use of data structures with larger size in \ac{hevc} was adopted to achieve higher coding efficiency especially in high resolution video. Each \ac{ctu} can be recursively partitioned into four smaller units, referred to as \acs{cu}, until it reaches the minimum unit size, which cannot be smaller than to $8\times8$ pixels. 
+Similar to the maximum \ac{ctu} size, the minimum size is also defined at the encoding time.
+For instance, in case of homogeneous regions, large \acs{cu} can be used to represent those regions
+by using a smaller number of symbols than is the case using several small units.
 Figure~\ref{Figure2:HEVCCodingStructure} illustrates an example of a \ac{ctu} partitioning into \acs{cu}. The partitioning illustrated in the figure leads to the quad-tree structure represented on the left side with the corresponding coding order shown on the right side.
+Data structures in \ac{hevc} provide a significant improvement in comparison with previous standards by eliminating the distinction between \ac{mb} and sub-\ac{mb} and using only \ac{cu}. This allows for the multilevel hierarchical quadtree structure to be specified in a simple and elegant way, with size-independent syntax representation.
+
+\begin{figure}[t]
+    \centering
+    \input{\FigsPath/BlockPartitionsWithTree.tikz}
+    \caption{Representation of a CTU ($64\times64$) and its partitioning into CUs and PUs (left); corresponding quad-tree with coding order (right)}
+    \label{Figure2:HEVCCodingStructure}
+\end{figure}
 
 \glsreset{pu}
 \glsreset{tu}
@@ -374,7 +379,7 @@ Figure~\ref{Figure2:HEVCCodingStructure} illustrates an example of a \ac{ctu} pa
 The \ac{cu} is the basic processing unit in \ac{hevc}. It is further partitioned into two types of units, specifically \ac{pu} and \ac{tu}, which are data blocks used for prediction and transform operations, respectively.
 The decision whether to use intra-frame or inter-frame prediction modes is taken at \ac{cu} level. However, depending on the partitioning of the \ac{cu} into \acs{pu} different intra or inter coding modes can be used for each \ac{pu}.
 
-\HERE
+
 
 %The main key feature of \ac{hevc} is the new block partition structure, which achieves more flexibility and efficiency. Four different block concepts have been introduced in the standard: \ac{ctu}, \ac{cu}, \ac{pu}, and \ac{tu}, all of which have different roles. Figure \ref{fig:HEVCBlockStructure} illustrates an example of a CTU partitioning in HEVC, and it is compared to the \ac{h264} \ac{mb} structure. CTUs are defined as the high-level partition within each slice and can be as large as 64$\times$64, which can be recursively partitioned into four smaller blocks referred to as CUs. The CU is the basic units for the intra/inter prediction and can be as small as 8$\times$8. Subsequently, the CU are divided into up to four PUs which are used for inter prediction. For intra coding PU is not used. Finally, the CU is divided into a transform unit tree, which may include several TUs, in a quad-tree structure. Transform units are the basic units for the transform operations applied to the coding residue.
 %