Graphics, Figures & Tables ⇒ \includegraphics makes image unsharp

[Rc3g]

Hi. I'm trying to include a png image in my LaTeX document but for some reason it shows up blurred, like it's been slightly upscaled. Surely the standard behavior of \includegraphics is to use the image's natural size? I don't really understand what's going on here. There are no errors when compiling the document (using pdflatex). I've obviously checked that there's nothing wrong with the image itself

This is the exact code I'm using:

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\begin{figure}[h]
\includegraphics{ferrers.png}
\caption{Examples of Ferrers diagrams. Note that $\mu/\lambda$ is not a border strip.}
\label{fig:ferrers}
\end{figure}

I've even tried specifying the exact width and height of the image (\includegraphics[width=330px,height=90px]{ferrers.png}), but it just makes it worse!

[localghost]

Try a certain scaling factor.

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\includegraphics[scale=0.75]{ferrers.png}

Th reason is the relation between the two units pixel and postscript point.


Best regards and welcome to the board
Thorsten¹

[Rc3g]

Thanks for your reply. I suppose that will work.

I've tried converting the image to a pdf, and then including the pdf. This makes everything nice and sharp, but once I start cropping (obviously I can't have a single page with just that figure on it), I get the same result as when I included the png. I don't suppose there is anything to do about this either (except scaling)?

[localghost]

[...] I've tried converting the image to a pdf, and then including the pdf. This makes everything nice and sharp, but once I start cropping (obviously I can't have a single page with just that figure on it), I get the same result as when I included the png. I don't suppose there is anything to do about this either (except scaling)?

Converting a pixel based format (PNG) to a vector based format (PDF) makes no sense because you can't benefit from advantages of the vector format. The best quality would be achieved by drawing these diagrams by hand with pgf/tikZ. But there will be a learning curve until you get familiar with that.

[Rc3g]

I see. Thanks.

[Rc3g]

My figure could be drawn very easily (and with acceptable quality) with MetaPost.

[localghost]

My figure could be drawn very easily (and with acceptable quality) with MetaPost.

I did two examples with pgf/tikZ. The first one with subfigures ...

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\documentclass[11pt,a4paper]{article}
\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage[english]{babel}
\usepackage{font=small,labelfont=sc]{caption}
\usepackage[font=footnotesize][subcaption}
\usepackage{nicefrac}
\usepackage{tikz}

\begin{document}
  \begin{figure}[!ht]
    \centering
    \begin{subfigure}{0.2\linewidth}
      \centering
      \begin{tikzpicture}[thick]
%        \draw[style=help lines] (0,0) grid (3,2);
        \foreach \position in {(0,0),(0,0.6),(0,1.2),(0.6,0.6),(0.6,1.2),(1.2,1.2),(1.8,1.2)}
        \draw \position rectangle +(0.5,0.5);
      \end{tikzpicture}
      \caption{$\mu=(421)$}\label{subfig-1:ferrers}
    \end{subfigure}
    \begin{subfigure}{0.2\linewidth}
      \centering
      \begin{tikzpicture}[thick]
%        \draw[style=help lines] (0,0) grid (3,2);
        \foreach \position in {(0,0.6),(0,1.2),(0.6,0.6),(0.6,1.2)}
        \draw \position rectangle +(0.5,0.5);
        \foreach \position in {(0,0),(1.2,1.2),(1.8,1.2)}
        \path \position rectangle +(0.5,0.5);
      \end{tikzpicture}
      \caption{$\lambda=(22)$}\label{subfig-2:ferrers}
    \end{subfigure}
    \begin{subfigure}{0.2\linewidth}
      \centering
      \begin{tikzpicture}[thick]
%        \draw[style=help lines] (0,0) grid (3,2);
        \foreach \position in {(0,0),(1.2,1.2),(1.8,1.2)}
        \draw \position rectangle +(0.5,0.5);
        \foreach \position in {(0,0.6),(0,1.2),(0.6,0.6),(0.6,1.2)}
        \path \position rectangle +(0.5,0.5);
      \end{tikzpicture}
      \caption{$\nicefrac{\mu}{\lambda}$}\label{subfig-3:ferrers}
    \end{subfigure}
    \caption[Examples of \textsc{Ferrers} diagrams]{Examples of \textsc{Ferrers} diagrams. Note that $\nicefrac{\mu}{\lambda}$ is not a border strip.}\label{fig:ferrers}
\end{figure}
\end{document}

... and the other one as single figure to make it look more like your screenshot.

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\documentclass[11pt,a4paper]{article}
\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage[english]{babel}
\usepackage{font=small,labelfont=sc]{caption}
\usepackage{nicefrac}
\usepackage{tikz}

\begin{document}
  \begin{figure}[!ht]
    \centering
    \begin{tikzpicture}[thick]
%      \draw[style=help lines] (0,0) grid (9,3);
      \foreach \position in {(0,0),(0,0.6),(0,1.2),(0.6,0.6),(0.6,1.2),(1.2,1.2),(1.8,1.2)}
        \draw \position rectangle +(0.5,0.5);
      \draw (1.5,2) node[above] {\small $\mu=(421)$};
      \begin{scope}[xshift=3cm]
        \foreach \position in {(0,0.6),(0,1.2),(0.6,0.6),(0.6,1.2)}
        \draw \position rectangle +(0.5,0.5);
        \draw (1.5,2) node[above] {\small $\lambda=(22)$};
      \end{scope}
      \begin{scope}[xshift=6cm]
        \foreach \position in {(0,0),(1.2,1.2),(1.8,1.2)}
          \draw \position rectangle +(0.5,0.5);
        \draw (1.5,2) node[above] {\small $\nicefrac{\mu}{\lambda}$};
      \end{scope}
    \end{tikzpicture}
    \caption[Examples of \textsc{Ferrers} diagrams]{Examples of \textsc{Ferrers} diagrams. Note that $\nicefrac{\mu}{\lambda}$ is not a border strip.}\label{fig:ferrers}
  \end{figure}
\end{document}

Nevertheless I'm also interested in a solution with MetaPost.

[phi]

Here is an example using Asymptote, which can be used to draw arbitrary diagrams of this kind. Compile with your platform equivalent of (pdf)latex AAA && asy AAA && (pdf)latex AAA:

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\documentclass{article}
\usepackage{asymptote}

\begin{document}

\begin{figure}
\centering
\begin{asy}
unitsize(6mm);
struct Ferrer {
	static path Box = box((0, 0), (0.8, -0.8));
	static int offset = 0;
	bool[][] values;
	bool get(int i, int j) {
		return values.initialized(i) && values[i].initialized(j) && values[i][j];
	}
	void set(int i, int j) {
		if(!values.initialized(i)) values[i] = new bool[];
		values[i][j] = true;
	}
	void operator init(...int[] r) {
		for(int i = 0; i < r.length; ++i) {
			for(int j = 0; j < r[i]; ++j) set(i,j);
		}
	}
	void Draw(string L) {
		int n = 0;
		for(int i = 0; i < values.length; ++i) {
			n = max(n, values[i].length);
			for(int j = 0; j < values[i].length; ++j) {
				currentpen = get(i,j) ? defaultpen : nullpen;
				draw(shift(offset+j, -i) * Box);
			}
		}
		label(L, (offset+n/2, 0), N, defaultpen);
		offset += n+2;
	}
}
Ferrer operator/(Ferrer L, Ferrer R) {
	Ferrer result;
	for(int i = 0; i < L.values.length; ++i) {
		for(int j = 0; j < L.values[i].length; ++j) {
			if(L.get(i,j) && !R.get(i,j)) result.set(i,j);
		}
	}
	return result;
}
Ferrer mu = Ferrer(4, 2, 1);
Ferrer lambda = Ferrer(2, 2);
mu.Draw("$\mu = (421)$");
lambda.Draw("$\lambda = (22)$");
(mu/lambda).Draw("$\mu/\lambda$");
\end{asy}
\caption{Examples of \textsc{Ferrers} diagrams. Note that $\mu/\lambda$ is not a border strip.}
\end{figure}

\end{document}