Here is a snippet that generates PNG images of arbitrary resolution (dpi):

# note: pymupdf can be imported as fitz 
# for backward compatibility (use `import pymupdf` in new code)
import fitz 
file_path = "my_file.pdf"
dpi = 300  # choose desired dpi here
zoom = dpi / 72  # zoom factor, standard: 72 dpi
magnify = fitz.Matrix(zoom, zoom)  # magnifies in x, resp. y direction
doc = fitz.open(fname)  # open document
for page in doc:
    pix = page.get_pixmap(matrix=magnify)  # render page to an image
    pix.save(f"page-{page.number}.png")

Generates PNG files name page-0.png, page-1.png, ... By choosing dpi < 72 thumbnail page images would be created.

Actually, it took me a while to handle this, but I think it worth it. You need to do all steps carefully to make it work.

1. Install pdf2image with pip install pdf2image.
2. Get poppler windows binaries.
3. Create a new directory like myproject.
4. Create a script converter.py inside myproject and add below code.
5. Create another directory inside myproject and name it poppler.
6. Copy all files in the binary folder of downloaded poppler into poppler directory. Try to test pdfimages.exe if it is working.
7. Use pyinstaller converter.py -F --add-data "./poppler/*;./poppler" --noupx
8. Your executable is now ready. Run it like converter.exe myfile.pdf. Results would be created inside the output directory next to the executable.
9. Now your standalone PDF2IMAGE converter app is ready!

converter.py:

import sys
import os
from pdf2image import convert_from_path


def current_path(dir_path):
    if hasattr(sys, '_MEIPASS'):
        return os.path.join(sys._MEIPASS, dir_path)
    return os.path.join(".", dir_path)


if __name__ == "__main__":
    if len(sys.argv) < 2:
        print("PASS your PDF file: \"converter.exe myfile.pdf\"")
        input()
        sys.exit(0)
    os.environ["PATH"] += os.pathsep + \
        os.pathsep.join([current_path("poppler")])

    if not os.path.isdir("./output"):
        os.makedirs("output")
    images = convert_from_path(sys.argv[-1], 500)
    for image, i in zip(images, (range(len(images)))):
        image.save('./output/out{}.png'.format(i), 'PNG')

PS: If you like it, you can add a GUI and add more settings for pdf2images.