Extract PNGs from 6-20 PDFs

I have between six and twenty PDF files that contain embedded PNG images. I need every one of those images extracted and delivered as standalone PNG files, keeping their original dimensions, transparency and colour profile intact.
Please organise the results in a clear folder structure—ideally one sub-folder per source PDF—and use logical filenames that let me trace any image back to its document. No editing, compression, or optimisation is required; this is a straight extraction job.

I will share the PDFs via Dropbox the moment we kick off. A single zipped archive with the organised PNGs is all I need back.

If you rely on Adobe Acrobat, Photoshop, or command-line tools such as Poppler or ImageMagick, that works for me; what matters most is accuracy and a quick turnaround. Let me know your estimated timeframe after you review a sample file.