From b9f511a8601405ecd2a023331097802fadf3184f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= Date: Sun, 16 May 2021 17:34:04 +0300 Subject: [PATCH] more explanations --- IV/Makefile | 24 ++++++++++------ IV/mj-msc.tex | 78 ++++++++++++++++++++++++++++++++------------------- 2 files changed, 65 insertions(+), 37 deletions(-) diff --git a/IV/Makefile b/IV/Makefile index 14f8273..b8e1626 100644 --- a/IV/Makefile +++ b/IV/Makefile @@ -40,9 +40,10 @@ RIVERS = \ salvis-visvalingam-64-chaikin-50k \ salvis-overlaid-douglas-64-chaikin-50k \ salvis-overlaid-visvalingam-64-chaikin-50k \ - salvis-wm-50k \ salvis-wm-250k \ - salvis-wm-overlaid-50k-zoom \ + salvis-wm-50k \ + salvis-wm-50k-nw \ + salvis-wm-50k-ne \ salvis-wm-overlaid-250k-zoom \ salvis-gdr50-overlaid @@ -199,15 +200,22 @@ salvis-overlaid-visvalingam-64-chaikin-50k_1COLOR = orange salvis-overlaid-visvalingam-64-chaikin-50k_WIDTHDIV = 2 salvis-overlaid-visvalingam-64-chaikin-50k_QUADRANT = 1 -salvis-wm-50k_1SELECT = wm_visuals where name='salvis-wm-75' -salvis-wm-50k_WIDTHDIV = 2 - salvis-wm-250k_1SELECT = wm_visuals where name='salvis-wm-220' salvis-wm-250k_WIDTHDIV = 10 -salvis-wm-overlaid-50k-zoom_1SELECT = wm_visuals where name='salvis-wm-75' -salvis-wm-overlaid-50k-zoom_2SELECT = wm_visuals where name='salvis' -salvis-wm-overlaid-50k-zoom_1COLOR = orange +salvis-wm-50k_1SELECT = wm_visuals where name='salvis-wm-75' +salvis-wm-50k_2SELECT = wm_visuals where name='salvis' +salvis-wm-50k_1COLOR = orange + +salvis-wm-50k-nw_1SELECT = wm_visuals where name='salvis-wm-75' +salvis-wm-50k-nw_2SELECT = wm_visuals where name='salvis' +salvis-wm-50k-nw_1COLOR = orange +salvis-wm-50k-nw_QUADRANT = 2 + +salvis-wm-50k-ne_1SELECT = wm_visuals where name='salvis-wm-75' +salvis-wm-50k-ne_2SELECT = wm_visuals where name='salvis' +salvis-wm-50k-ne_1COLOR = orange +salvis-wm-50k-ne_QUADRANT = 1 salvis-wm-overlaid-250k-zoom_1SELECT = wm_visuals where name='salvis-wm-220' salvis-wm-overlaid-250k-zoom_2SELECT = wm_visuals where name='salvis' diff --git a/IV/mj-msc.tex b/IV/mj-msc.tex index fed0358..f1c0ed5 100644 --- a/IV/mj-msc.tex +++ b/IV/mj-msc.tex @@ -1378,45 +1378,49 @@ table~\ref{table:scale-halfcirlce-diameter}: \subsubsection{Medium-scale (1:\numprint{50000})} \label{sec:analyzed-medium-scale} -\begin{figure}[ht] +\begin{figure}[h!] \centering - \begin{subfigure}[b]{.49\textwidth} - \includegraphics[width=\textwidth]{salvis-50k} - \caption{Original.} - \end{subfigure} - \hfill - \begin{subfigure}[b]{.49\textwidth} - \centering - \includegraphics[width=\textwidth]{salvis-wm-50k} - \caption{Simplified.} - \end{subfigure} - \caption{Simplified with {\WM} for 1:\numprint{50000}.} + \includegraphics[width=\textwidth]{salvis-wm-50k} + \caption{2x zoomed-in {\WM} for 1:\numprint{50000}.} \label{fig:salvis-wm-50k} \end{figure} As one can see in figure~\ref{fig:salvis-wm-50k}, the illustrations deliver -what was promised by the algorithm, but with a few caveats. West-side of the -river looks reasonably well simplified: long bends remain slightly curved, +what was promised by the algorithm, but with a few caveats. Left side of the +figure looks reasonably well simplified: long bends remain slightly curved, small bends are removed or slightly exaggerated. -Approximately at the middle of the figure some jagged and sharp bends appear. -Figure~\ref{fig:salvis-wm-50k-overlaid-zoom} zooms in, overlaying the original -river (in orange). These will become more pronounced in even larger-scale +Figure's~\ref{fig:salvis-wm-50k} left part is clipped to +figure~\ref{fig:salvis-wm-50k-nw}. As one can see, some bends were well +exaggerated, and some bends were eliminated. + +\begin{figure}[h!] + \centering + \includegraphics[width=\textwidth]{salvis-wm-50k-nw} + \caption{Left part of figure~\ref{fig:salvis-wm-50k}.} + \label{fig:salvis-wm-50k-nw} +\end{figure} + +Top--right side (clipped in figure~\ref{fig:salvis-wm-50k-ne}) some jagged +and sharp bends appear. These will become more pronounced in even larger-scale simplification in the next section. -\begin{figure}[ht] +\begin{figure}[h!] \centering - \includegraphics[width=\textwidth]{salvis-wm-overlaid-50k-zoom} - \caption{2x zoomed-in {\WM} for 1:\numprint{50000}.} - \label{fig:salvis-wm-50k-overlaid-zoom} + \includegraphics[width=\textwidth]{salvis-wm-50k-ne} + \caption{Top--right part of figure~\ref{fig:salvis-wm-50k}.} + \label{fig:salvis-wm-50k-ne} \end{figure} +To sum up, mid-scale simplification works well for some geometries, but creates +sharp edges for others. + \subsubsection{Large-scale (1:\numprint{250000})} As visible in figure~\ref{fig:salvis-wm-250k}, for large-scale map, some of the resulting bends look significantly exaggerated. Why is that? Figure~\ref{fig:salvis-wm-250k-overlaid-zoom} zooms in the large-scale -simplification and overlays the original (in orange). +simplification and overlays the original. \begin{figure}[ht] \centering @@ -1431,7 +1435,7 @@ simplification and overlays the original (in orange). \includegraphics[width=.2\textwidth]{salvis-wm-250k} \caption{Simplified.} \end{subfigure} - \caption{Simplified with {\WM} for 1:\numprint{250000}.} + \caption{GDB10LT simplified with {\WM} for 1:\numprint{250000}.} \label{fig:salvis-wm-250k} \end{figure} @@ -1442,11 +1446,27 @@ simplification and overlays the original (in orange). \label{fig:salvis-wm-250k-overlaid-zoom} \end{figure} -A conglomeration of bends is visible, especially in north-east side of the -center. We assume this was caused by two bends significantly exaggerated, -leaving no space to exaggerate for those between the two. For the same reason, -the figure~\ref{fig:salvis-wm-50k} (of scale 1:\numprint{50000}) has many -smaller bends at approximately the same location. +A conglomeration of bends is visible, especially in top--right side of the +illustration. We assume this was caused by two bends significantly exaggerated, +leaving no space to exaggerate for those between the two. + +\subsubsection{Discussion} + +For mid-size scales of 1:\numprint{50000}, the implemented algorithm works well +for certain geometries, and poorly for others. This test surfaced two areas for +future research and improvement: + +\begin{itemize} + + \item Exaggeration is sometimes creating sharp edges, especially when the + exaggerated bend is quite small. When sharp edges are created, + exaggeration could interpolate more points in the bend, and exaggerate + using the interpolated points. + + \item In larger scales, when bends do not have space to exaggerate, they + should be combined or eliminated instead. + +\end{itemize} \subsection{Comparing Generalized Result with National Spatial Datasets} @@ -1547,7 +1567,7 @@ implementation: \item Fine-tune parameters for bend exaggeration. Section~\ref{sec:generalization-results-of-analyzed-rivers} contains - a exaggerated bends that became sharp. + a exaggerated bends that became sharp and includes some future ideas. \item Research when bends should be marked as \textsc{isolated}. As is seen from examples, the current criteria is not robust enough.