LaTeX images formatting

Question

I'm writing a report and inserting a few raster images in (in PNG format) using:

\usepackage[pdftex]{graphicx}

\includegraphics[width=4in]{poker.png}

My problem is that when saving as a PDF the images are look really awful, am I missing something?

Answer 1

I do the exact thing all the time, and it always looks good.

Perhaps it is the pdf viewer that renders it badly? (I use xpdf mostly.)

Maybe you can post screenshots of the image, and how it looks in the pdf document?

Answer 2

The image file poker.png has a poor resolution. The cropped text has 90 × 56 pixels only. The resolution is 72 DPI, This is not suitable for printing unless it is scaled down.

The PDF specification knows a key Interpolation for bitmap images:

Image Interpolation

When the resolution of a source image is significantly lower than that of the output device, each source sample covers many device pixels. As a result, images can appear jaggy or blocky. These visual artifacts can be reduced by applying an image interpolation algorithm during rendering. Instead of painting all pixels covered by a source sample with the same color, image interpolation attempts to produce a smooth transition between adjacent sample values.

Image interpolation is enabled by setting the Interpolate entry in the image dictionary to true. It is disabled by default because it may increase the time required to render the image.

Note: The interpolation algorithm is implementation-dependent and is not specified by PDF. Image interpolation may not always be performed for some classes of images or on some output devices.

Driver pdtex.def supports it by option interpolate:

\includegraphics[interpolate]{poker.png}

It depends on the PDF viewer, whether this feature is implemented. Example for the image without interpolation:

With interpolation:

A better variant is to replace the image by a vector graphics. The font seems to be Helvetica. The following example uses the clone TeX Gyre Heros:

\documentclass{standalone}
\usepackage{graphicx}
\usepackage{color}

\begin{document}
\scalebox{3}{%
  \setlength{\fboxsep}{2mm}%
  \colorbox{black}{%
    \textcolor{white}{%
      \usefont{T1}{qhv}{bx}{n}%
      \begin{tabular}{@{}c@{}}%
        P\kern-.15exO\kern-.18exK\kern-.175exE\kern-.21exR\\%
        F\kern-.35exA\kern-.25exC\kern-.2exE%
      \end{tabular}%
    }%
  }%
}
\end{document}

Answer 3

Years ago I had similar problem. The solution was to use directly pdflatex, instead of latex and dvipdf.

Alternative was to convert PNG to EPS.

Answer 4

I've always had the same problem, but the print is always fine. The only solution I know is to use vectorial images, but it's not always possible.

To me the problem juste comes from the fact the PDF viewer scales the image badly. There are often strange things like this, for example some capitals look wrong with Adobe's viewer, but once it's printed the result is always fine.

(You don't need to put the .png extension in the file name: graphicx automatically looks for the image with that name which has the best quality.)

Answer 5

Are you viewing the PDF in original size? And is the image included in the document in it's original size? Resizing the image can result in awful images.