1. A fingerprint/palmprint image processor comprising: a reading-in part for reading-in a fingerprint or palmprint as an image; an extracting part for dividing a fingerprint/palmprint image into local regions and extracting ridge candidates showing ridges for each local region; a determining part for determining candidate images that are highly likely to be ridges among the extracted ridge candidate images and local regions including the determined candidate images as highly reliable regions; a judging part for judging whether or not local regions other than the highly reliable regions are ridge exclusive regions including the existence of ridges only or crease and ridge mixed regions including a mixture of creases and ridges; a selecting part for selecting candidate images that are supposed to show ridges among ridge candidate images based on evaluation criteria adapted to each of the ridge exclusive regions and crease and ridge mixed regions; and a generating part for generating a whole image based on the candidate images of the highly reliable region determining part and the candidate images selected by the selecting part.