# Low quality in tex->dvi->ps->pdf

I took a screenshot an then saved as EPS using photoshop. This EPS looks well as it's original source. I use the following code to insert the image:

\begin{figure}[H]\begin{center}
\centering
\captionsetup{justification=centering}
\includegraphics[width=1\textwidth]{pictures/proposal/aaaida_use_case}
\caption{lorem ipsum \label{fig:network-architecture}}
\end{center}\end{figure}

When I compile the tex to dvi, then ps and finally pdf, the resulting image included in the document has a very poor quality, like a JPEG when you save it several times (recompression with quality loss)

Instead of this, if I compile directly to dvi and then pdf it shows nice.

And if instead of saving to EPS I save the image to PDF, using PDFLatex also looks fine.

So I don't understand why the PS step is loosing quality (image recompression).

Finally I don't understand pretty well the differences between DVI->PS->PDF and DVI->PDF on terms of the resulting document.