# Image quality using PDFLaTeX

I've got some PNG images within my LaTeX document. The quality of the image files is sufficient and the result using LaTeX and viewing the resulting DVI file is quite what I expect - looks good.

But I would need such quality of the images in my PDF files as well. But unfortunately when using PDFLaTeX the images are surprisingly worse quality in the resulting PDF file.

How can the quality for the resulting PDF file be improved?

I think there's happening some kind of rasterization which makes the images showing up in bad quality.

(I tried using `dvi2pdf` or `ps2pdf` but the quality of the final PDF was the same. Additionally I would like to have a PDF ToC and the `hyperref-pdf` features when using PDFLaTeX)

Searching the web I found the following but I'm not quite sure if this helps and were to set the mentioned parameters on my *buntu
http://www.mackichan.com/index.html?techtalk/581.htm~mainFrame

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What format are your image files in? –  Jan Hlavacek Dec 17 '11 at 4:47
@Jan Hlavacek: They're png image files. –  Meinzlein Dec 17 '11 at 9:17
@Meinzlein: pdflatex includes PNG images without altering them, so the quality remains unchanged. Most likely, this is a problem with your PDF viewer, see e.g. tex.stackexchange.com/a/10978/2552. What viewer are you using? Have you tried printing the document (the quality should be better in a printout)? –  Jake Dec 17 '11 at 9:31
@Meinzlein: Those parameters don't apply here, that article is concerned with converting from other formats to PNG. You're already using PNG, no conversion (or rasterisation) is taking place. The image is included in your document in the full, unchanged quality, so there's not much you can (or need to) do. What viewer are you using? –  Jake Dec 17 '11 at 9:42
@Meinzlein: Ah, Okular is not smoothing the image (it doesn't on my system, either), and this is one of the cases where smoothing would actually be better. Since Evince smoothes all images, in this case it looks better. In the case shown at tex.stackexchange.com/a/10978/2552, smoothing is undesirable, but generally it's a good idea. I wouldn't worry about this in this case: You know that the pictures are included in perfect quality, and most people would be viewing the file in Acrobat or Evince (both smooth) anyway. By the way, typo in the second last line ("bilogische"). –  Jake Dec 17 '11 at 10:13