Every raster image goes into a PDF the same way: as an Image XObject scaled onto a page rectangle. The only real decision is what DPI to declare. That number controls whether a 4032×3024 photo land…
The pipeline has hard limits. Some come from the formats: PDF cannot animate, signatures cannot survive a byte change. Others come from the server side: LibreOffice without the right fonts, no OCR,…
A user drops a docx, three iPhone photos, a TIFF scan, a DjVu book, and an existing PDF into the upload box and clicks Combine. One PDF comes back. Behind the button is a pipeline with a per-format…