1. A standard memory take-in method for selecting a set of standard data for use with a pattern recognition system in which a plurality of samples of data representing a single known object to be recognized and stored as a set of standard data are stored, said plurality of samples being compared with data representing a subsequent sample to decide whether or not said subsequent sample belonging to said single known object should be stored, said standard memory take-in method comprising the steps of: a. storing a first coming sample of data representing said object in a memory unconditionally as a standard data; b. setting a predetermined threshold value which is used to determine whether or not a second coming sample of data is stored as a standard data; c. taking in said second coming sample of data; d. calculating a difference between said first coming sample of data and said second coming sample of data; e. storing said second coming sample of data in said memory only if said difference exceeds said predetermined threshold value and refusing to store said second coming sample of data in said memory if said difference is less than said predetermined threshold value; f. calculating differences between each subsequent sample of data and each sample of data previously stored in said memory; g. storing each subsequent sample of data in said memory only if all of said differences exceed said predetermined threshold value and refusing to store said subsequent sample of data in said memory if any of said differences is less than said predetermined threshold value; h. checking whether said memory is fulfilled or not; and i. repeating said steps c to g when said memory is not fulfilled to fulfil said memory.