There are many people suffering from loss of hair or thinning hair. There are, however, no methods to quantitatively know their hair condition such as hair density and hair thickness without cutting the hairs. Our final target is to develop a system which enables general people to easily and quantitatively know their hair condition without cutting the hairs. As the first step, a method has been developed to extract the positions of the hair roots. The method covers the case where the hairs are extracted by binarization. Preliminary results show promising performance of about 82% F-measure.