HOLOGRAPHIC METHOD WITH NUMERICAL RECONSTRUCTION FOR OBTAINING AN IMAGE OF A THREE-DIMENSIONAL OBJECT IN WHICH EVEN POINTS OUT OF THE DEPTH OF FIELD ARE IN FOCUS, AND HOLOGRAPHIC APPARATUS USING SUCH A METHOD

摘要

The invention concerns a holographic method with numerical reconstruction for obtaining an image of a three-dimensional object, said method employing a digitalised hologram of an object, and comprising a step A. wherein, starting from the digitalised hologram, extracting a phase image of said object corresponding to a bidimensional matrix MD of distance values; a step B. wherein a monodimensional subassembly SD of the distance value assembly present in matrix MD of the method step A is selected, subassembly SD containing distance values dk; a step C. wherein for each distance value dk, extracting from matrix MD a iso-level assembly IQdk corresponding to a monodimensional assembly of bidimensional coordinates of said object,- a step D. wherein for each distance value dk, reconstructing, starting from the digitalised hologram, a bidimensional matrix IMdk of intensity values relevant to said object; a step E. wherein, from each bidimensional matrix IMdk a bidimensional matrix IFdk of intensity values is extracted corresponding to the bidimensional coordinates of the iso-level assembly IQdk; a step F. wherein, starting from intensity values IFdk from the bidimensional coordinates of the iso-level assembly IQdk and from the relevant distance values dk, reconstructing the three-dimensional intensity image of said object, and wherein the resolution of the bidimensional matrix IMdk for all values of k is identical to the resolution of matrix MD of distance values.