[Tex/LaTex] PNG DPI and image size

graphicspdfpng

I created a PNG file (763px by 600px at 72DPI) from a free image. I opened the image in GIMP and changed the DPI to 300 and saved it. After including it in a LaTeX file with

\includegraphics[scale=1.0]{file.png}

and running pdflatex, the image looked good on the page. I wanted it a little bit larger, so I changed the DPI in GIMP to 600 and saved the file. After recompiling the source, the image is now much smaller on the output PDF. What have I done wrong?

Best Answer

The DPI measure the displayed number of Dot Per Inch. If you increase the DPI, it is normal that your picture dimensions will decrease at the same scale.

You do not need to change the DPI, you should insert your image like this:

\includegraphics[width=Xcm]{file.png}

to have a picture of a width equal to Xcm (height automatically adjusted, or height=Xcm). Or:

\includegraphics[width=Xcm,height=Ycm,keepaspectratio]{file.png}

to have an image of X by Y cm, with respect to proportion.

The DPI matter is important in that way: if you have a picture of 1in x 1in at 100 DPI (ie 100px x 100 px), the scaling to 6in x 6in will not look good...

Related Solutions

[Tex/LaTex] Convert GIF image to PNG on the fly

You need to enable shell escapes. With MiKTeX you do -enable-write18 and with TeXlive -shell-escape.

You can set up different conversion rules with the epstopdf package

\documentclass{article}
\usepackage{graphicx}
\usepackage{epstopdf}
\epstopdfDeclareGraphicsRule
  {.gif}{png}{.png}{convert gif:\SourceFile.\SourceExt png:\OutputFile}
\AppendGraphicsExtensions{.gif}


\begin{document}

\includegraphics{test.gif}

\end{document}

Using epstopdf you can control if the conversion should be done every time you compile or only if the target file is missing.

[Tex/LaTex] CMYK poster example: fitting pdf page size to (bitmap) image size

How can I generate an A4 PDF, from an a4@300 PPI bitmap, using pdflatex (or if there is a better alternative to pdflatex, which one?)

You can use the standalone class to get a PDF which is just as large as the the image, which gives you A4 if the image is in the size of A4. If the image is actually a PDF document the pdfpages package would be better suited.

\documentclass[border=0]{standalone}
% For older version without the `border` option:
% \renewcommand{\PreviewBorder}{0bp}
\usepackage{graphicx}
\begin{document}
\includegraphics{someA4image.png}
\end{document}

Which image format should I use, so that I ensure that the generated PDF file is in CMYK color mode?

If you are going to use pdflatex there are only PDF, PNG and JPG (or maybe MetaPost, but that support might also been dropped). You shouldn't use JPG because of the loss of quality. If you don't want to use PDF than only PNG remains. You could export the inkscrape document to EPS and import this in a DVI/PS latex document instead. Or convert the EPS to PDF using epstopdf and hope your printer likes it.

I personally wouldn't try to export, convert and import a poster from one software to the other like that. I would mind the loss of quality and the arising troubles.

Best Answer

Related Solutions

[Tex/LaTex] Convert GIF image to PNG on the fly

[Tex/LaTex] CMYK poster example: fitting pdf page size to (bitmap) image size

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