I have a bmp file (or it could be any image file type).
How can I convert it to a same dimensions pdf? (because online converters I have found tend to convert it to a full a4 dimensions pdf, where the picture is somewhere in the page and the rest of the page is blank)
I tend to use this online converter : Link to a pdf converter I tried it with an image and it did not give me a A4 size.
With LaTeX you can create a document containing :
\documentclass{standalone}
\usepackage{graphicx}
\begin{document}
\includegraphics[scale=1]{file.png}
\end{document}
and compile it with PDFLaTeX.