To provide a registration apparatus, a collation apparatus, an extraction method and an extraction program capable of improving authentication accuracy. An image signal obtained by imaging a biometric subject in a predetermined biological position is subjected to predetermined processing so as to extract a feature portion of the biometric subject in the image signal. The feature portion is subjected to Hough transform. Parameter extraction is performed by changing the extraction condition such that the number of parameters obtained by the Hough transform becomes a predetermined value. In the case where the value of the extraction condition at the time point when the number of parameters is the predetermined value falls within a range from the upper limit set value to the lower limit set value, the predetermined number of parameters are set as registration data or data to be collated with the registration data.