These are proper PDF rip, not lossy rips from Koushoku viewer.

Part 1 (native PNG) & Part 2 (PDF rip)

@RattlesnakeOozer
Native PNG: Fakku Store untouched download. They let you choose between PNG and PDF.
Proper PDF rip: Irodori Store only has PDF. To get the images you must use poppler’s pdfimages and then losslessly optimize them with pinga (GUI) or pingo (CLI):

1. Download the latest poppler binary HERE
2. Extract the bin folder from .zip\Library and use pdfimages.exe inside it with these commands:
   pdfimages.exe -j -png "pdf file path" "output folder path and prefix for img name"
3. Download, extract and install pinga from HERE
4. Run it and change the settings to THIS to avoid using lossy conversions.
5. Add the extracted images (both JPGs and PNGs) and hit the optimize button. JPGs will be handled losslessly too.