Grains of rice are pretty big, and the images they demonstrate are NOT that impressive. There are cameras you can BUY right now whose size is 1x1x2 mm (smaller than a grain if rice) which produce images that compare. Here is one example: https://www.digikey.com/en/products/detail/ams-osram-usa-inc...

It is pretty easy to interface with too - i did it with a pi pico microcontroller: https://x.com/dmitrygr/status/1753585604971917313

The OP describes them as the size of a grain of salt, not a grain of rice.