Combine multiple image files into a single PDF file

Question

What's a good utility for combining different image files (e.g. PNGs or JPGs) into a single PDF file, with no quality loss (or minimal quality loss)?

Required features:

• Libre
• Gratis
• Command-line
• Runs on Linux
• Runs on x86_64 machines

Desired features:

• Cross platform
• Fast

Answer 1

One possibility is to use imagemagick on each image individually:

convert foo.png foo.pdf

then combine them all with

pdfunite foo.pdf bar.pdf baz.pdf output.pdf

but make sure to list the PDFs in order. pdfunite is part of the Poppler project, and is FOSS; and so is imagemagick.