Photorefractive Fe:LiNbO_3 crystal thin plates for optical information processing

Holographic read - write projector of video images

“…On the other hand the photorefractive crystals have been extensively used as holographic memories of 2D pages of data [12][13][14][15]. The use of error correction algorithms for the digital data pages recorded in the PRCs has lead to very low error rates [16,17].…”

Face Recognition System with Holographic Memory and Stereovision Technology

“…Many researchers have proposed the high-speed optical correlator with holographic memories and applied it to character recognition and data retrieval, for example. [1][2][3][4][5] The fast recognition optical correlator (FARCO) is one of the successful applications, and it achieves high-speed processing of over 100,000 faces/s. 6) However, face recognition systems based on the correlator of two dimensional (2D) images often has the problem that a small difference in the face-to-camera angle of the input data from that of reference data causes serious reduction of the cross-correlation even if the persons in the facial images are the same.…”

“…We detected the corner positions of the eyes and mouth in the picture with more precision by the pattern-matching method using template images. (3) We calculated the disparity between the two pictures captured from the stereocamera in only the facial region, and obtained the 3D geometry of the face. (4) The facial angle of the 3D object was adjusted to position the corners of the eyes and mouth on the same x-y plane, where x-, y-, and z-axes indicate the horizontal, perpendicular, and depth directions, respectively.…”