Mobile phone length measuring method based on bank card

The invention relates to a mobile phone length measuring method based on a bank card. The method includes the following steps that (1) a to-be-measured object and the bank card are put in the same plane, angle of a mobile phone is adjusted, and the mobile phone shoots the object and the bank card; (2) the bank card in a picture is detected and the length of the bank card in the picture is calculated; (3) a to-be-detected object in the picture is determined and the length of the to-be-detected object in the picture is calculated; (4) the length of the bank card in the picture is compared with the length of the to-be-detected object in the picture, and actual length of the to-be-detected object is calculated. By means of the mobile phone length measuring method based on the bank card, the problem of size measurement of a target object by the mobile phone is solved, the operation is simple, global unity feature is achieved on basis of length and width of the bank card, the bank card is used as the standard so that the stability and the universality of the method can be further achieved, and the demands of daily life of people can be met.