The iPhone photo contest is also why mobile phones are completely different.

Photography can be divided into prophase and anaphase. For the same machine, the previous differences include three elements: scene, position, focal length and exposure. The later stage includes white balance, exposure, contrast, sharpness, noise, color difference, distortion, color scale, saturation and so on. There are many algorithms for once correction. Even if the early stage is similar, the later stage can completely set off the ever-changing characteristics.