Patent ID: 7123761

Claim:
A feature extracting method for a radiation image formed by radiation image signals each corresponding to an amount of radiation that has passed through a radiographed subject, said method comprising: a plurality of different feature extracting steps, each of which has a respective feature extracting condition to extract a respective feature value so that a plurality of different feature values are extracted from the radiation image by the plurality of different feature extracting steps; a feature value evaluating step of evaluating a combination of the plurality of different feature values extracted by the plurality of different feature extracting steps; and a controlling step of: selecting at least one feature extracting step from the plurality of different feature extracting steps based on an evaluation result by the feature value evaluating step, changing the feature extracting condition of the selected feature extracting step, and conducting the selected feature extracting step again so as to extract from the radiation image a feature value based on the changed feature extracting condition; wherein the controlling step includes investigating the coordination of the combination of the plurality of different feature values, and when it is judged in the controlling step that the combination of the plurality of different feature values is not coordinated, the feature value to be extracted again is selected based on the uncoordinated combination of the plurality of different feature values and conducts the selected feature extracting step again.