PDFGen VS libvips

Maybe I'm too late to the party, but today I saw 'PDFGen', which seems to be exactly what you're looking for.

MCLib is actually "close enough" to the environment that plain C expects that I was able to port a ~3000 line C library for building PDF files in maybe an hour or two a few weeks back. And in that time, MCLib has been getting better and better at faking the environment that C expects, so it is likely even easier to port code now.

After some research, I found libvips, a demand-driven, horizontally threaded image processing library. It is designed to run quickly while using as little as memory as possible.

Sharp is a fast and efficient image optimization Node.js module that makes use of the native libvips library.

h2non/bimg can handle both if the underlying libvips is compiled with support for both formats.

if you're using linux (which it doesn't seem so) there's also vispdisp https://github.com/jcupitt/vipsdisp which is based on https://github.com/libvips/libvips which will likely take over how images are decoded in the future for everything, at least methodology wise.

The magic happens by way of a library called Libvips, which contains an ultra-high-speed low-memory image resizer.

imagor uses one of the most efficient image processing library libvips. It is typically 4-8x faster than using the quickest ImageMagick and GraphicsMagick settings.

Try the solutions here: https://github.com/libvips/libvips/issues/2479

in that case maybe take a look at https://github.com/libvips/libvips

libvips v8.6+ or ImageMagick for image analysis and transformations