1. A method comprising: capturing an RGB image of a hand of a person; capturing a near infrared (NIR) image of the hand; producing a resultant binary image from the RGB image and the NIR image using reflectance values derived from pixels of the RGB image and corresponding pixels of the NIR image, the resultant binary image comprising a first binary pixel value for skin tissue areas in the RGB image and the NIR image corresponding to the hand of the person, the resultant binary image further comprising a second binary pixel value for non-skin areas in the RGB image and the NIR image, wherein the first binary pixel value is determined for a pixel of the binary image when a first value associated with the pixel is within a first predetermined value range and when a second value associated with the pixel is within a second predetermined value range, the first value being determined based on a comparison between a reflectance value of a color component of a pixel of the RGB image and a reflectance value of a corresponding pixel of the NIR image, and the second value being determined based on a comparison between a reflectance value of a first color component of the pixel and a reflectance value of a second color component of the pixel; determining, from the resultant binary image with the extracted hand image data corresponding to the skin tissue of the hand of the person, geometrical features of the hand; and determining whether the person is authorized to access a device based on the geometric features of the hand extracted from the resultant binary image.