Optical information recording/reproducing device, optical information reproducing device, and optical information reproducing method

An optical information reproducing device which reproduces information recorded by performing two-dimensional encoding to an interference pattern between a reference beam and a signal beam as a hologram in an optical information storage medium, the optical information reproducing device comprising:

• a light source unit configured to emit a light beam;
• a reference-beam optical unit configured to generate the reference beam from the light beam, and to irradiate the optical information storage medium;
• a photodetection unit configured to detect a reproduced beam from the optical information storage medium, and to acquire a reproduced image constituted by a plurality of pixels arrayed in a lattice shape;
• and
• a signal processing unit configured to perform, based on a rule of the two-dimensional encoding, equalization processing to a first pixel of the reproduced image using a filter used to equalize the first pixel and having a filter shape which is an array shape of the first pixel and peripheral pixels of the first pixel, wherein
• the filter shape has a different number of coefficients in a first direction from the number of coefficients in a second direction perpendicular to the first direction.

An optical information reproducing method for reproducing information recorded by performing two-dimensional encoding to an interference pattern between a reference beam and a signal beam as a hologram in an optical information storage medium, the optical information reproducing method comprising:

• a light beam emission step of emitting a light beam;
• a reference beam irradiation step of generating the reference beam from the light beam, and irradiating the optical information storage medium;
• a photodetection step of detecting a reproduced beam from the optical information storage medium, and acquiring a reproduced image constituted by a plurality of pixels arrayed in a lattice shape;
• and
• a signal processing step of performing equalization processing to a first pixel of the reproduced image using peripheral pixels existing around the first pixel, wherein
• the peripheral pixels are pixels arrayed in a rectangular region centered at the first pixel in the reproduced image and having a different number of pixels in the first direction from the number of pixels in the second direction perpendicular to the first direction.