How to achieve the requirement of uploading pictures on the global photography network? Limit it to 12 million pixels. How?

The length of one side is not less than 1 pixels, so it should be easy to take photos now, right? Mobile phone photos can meet this requirement.

the concept of limiting 12 million pixels you mentioned is different from other people's requirements. If you don't understand, you can continue to ask questions or write privately. I feel that you don't understand the requirements of others.