Comment by paxys

They are very different problems. You can attach every kind of sensor to the phone and get HD images, lidar scan, 3D model, heat signature and whatever other signal you want, but you still won't be able to figure out calories in a piece of food without breaking it apart at a molecular level. There's just too much hidden information. What sensor will tell you how many tablespoons of oil the chef used to fry onions for the sauce? Heck the chef himself probably won't be able to tell you.