Point-of-sale terminal, checkout system, and storage medium

A checkout system comprising:

• an attendant terminal;
• and
• a point-of-sale (POS) terminal including:
• a communication interface connectable to the attendant terminal,
• a first table on which one or more commodities that have been registered for purchase can be placed,
• a weight sensor disposed in or under the first table,
• a camera positioned to image the first table,
• a memory that stores a program and a plurality of commodity information each indicating a commodity, a weight range of the commodity, and a preset image of the commodity, and
• a processor configured to execute the program to:
• determine whether a first operation for registering a first commodity is input,
• upon determining that the first operation is input, search the memory for first commodity information corresponding to the first commodity,
• determine whether a weight measured by the weight sensor increases after the first operation,
• upon determining that the measured weight increases, determine whether an increase in the measured weight is within a first weight range indicated by the first commodity information,
• upon determining that the increase is within the first weight range, register the first commodity, and
• upon determining that the increase is not within the first weight range,
• determine whether a first image captured by the camera after the first operation shows the first commodity based on a first preset image indicated by the first commodity information,
• upon determining that the first image shows the first commodity, register the first commodity, and
• upon determining that the first image does not show the first commodity, control the communication interface to transmit an error signal to the attendant terminal.

A non-transitory computer readable storage medium that causes a computer to execute a method comprising:

• storing in a memory a plurality of commodity information each indicating a commodity, a weight range of the commodity, and a preset image of the commodity;
• determining whether a first operation for registering a first commodity is input;
• upon determining that the first operation is input, searching the memory for first commodity information corresponding to the first commodity;
• determining whether a weight measured by a weight sensor increases after the first operation, the weight sensor being disposed in or under a first table on which one or more commodities that have been registered can be placed;
• upon determining that the measured weight increases, determining whether an increase in the measured weight is within a first weight range indicated by the first commodity information;
• upon determining that the increase is within the first weight range, registering the first commodity;
• and
• upon determining that the increase is not within the first weight range,
• determining whether a first image captured by a camera after the first operation shows the first commodity based on a first preset image indicated by the first commodity information, the camera being positioned to image the first table,
• upon determining that the first image shows the first commodity, registering the first commodity, and
• upon determining that the first image does not show the first commodity, issuing an error signal.