How does mobile photography convert black-and-white photos into color?

Step 1: Choose the mobile phone with the highest pixel (preferably SLR), find a pure white backlight with uniform light as the background (if you can't find it, use another mobile phone to adjust the screen to pure white and the backlight to the brightest), and don't be too bright indoors to ensure that the backlight is bright enough and the light is uniform. Put the film on it, hold the mobile phone (camera) steady, and shoot as close as possible to the negative film on the premise of ensuring accurate focusing, which is also to improve the clarity of the negative film. (Remember not to shoot with beauty, beauty will lose details) to lay a good foundation for better correction in the future.

Step 2: This is the most critical step and the simplest step. By using an APP with negative function (at present, most smartphones have picture editing function), the photographed negative is converted into color pictures, and this is completed.

Step 3: At this time, the converted picture may appear gray due to insufficient backlight brightness or camera reasons. In this case, it is necessary to post-color the converted image, and the post-processing applications include Snapseed, ps mobile phone, or Meitu Xiu Xiu. This step may be difficult for some retouching. Snapseed is recommended for mobile phones that know retouching, and Meitu Xiu Xiu is recommended for inexperienced phones. Use these softwares to color the pictures until you are satisfied. It's not just the color that needs to be repaired here, because old negatives often have scratches or spots, so we need to focus on this kind of repair (the above app has repair function).