[Tex/LaTex] Error including a .png: Cannot determine size of graphic


I have a little problem: I am not able to put an image in my document.
This is how I start:

















and this is the error report:

ERROR: LaTeX Error: Cannot determine size of graphic in mol.png (no BoundingBox).

--- TeX said ---

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.

l.67 \includegraphics{mol.png}

Some months ago I used the same procedure and it worked.

I even tried to reproduce the .dvi file from the .tex file that I wrote some months ago but today doesn't work.

Another question: how can I produce a .pdf file from a .tex file? I forgot it.

I'm working on debian using emacs

Best Answer

If you use the command latex (making dvi) you need to specify the natural size the image natwidth=... natwidth=... (not width= as that tries to scale to that size but still needs the natural size. If you use the command pdflatex (making pdf directly) Then the system can read the file and determine its natural size automatically. In either case it is usually a good idea to omit the extension .png then if different systems understand different image formats they will each pick up the right format.