Fast computational method for digital Cylindrical holography

Abstract

Holograms can record and reproduce all the three dimensional information like motion parallax, accommodation, occlusion, convergence and so on. Hence it is possible to perceive a three dimensional object very close to reality, when looking into a hologram, from any direction. But the potential of the holography is restricted by the geometrical shape of the hologram. Accordingly, the main aim of this work is to develop a new numerical procedure and programming scheme inorder to achieve faster and efficient generation and reconstruction of the cylindrical hologram on the computer. A hologram was made for cylindrical object using the numerical method proposed in this work. The cylindrical hologram was able to successfully reconstruct the object back using the same numerical method. Inorder to test the correctness of the hologram, the reconstructions were also performed on plane surfaces using direct integration. A segmentation algorithm was executed on the reconstruction inorder to get rid of the defocused reconstructions. This procedure resulted in a good reconstruction of the 3D object. Thus it was verified that this numerical method can successfully reconstruct 3D objects which has potential applications in 360and#9702; microscopy. The calculation procedure proposed in this work can be highly parallelized. This property of the calculation method has been put to full use by implementing the entire calculation on a General Purpose Graphics Processing Unit (GP-GPU). Execution on the GP-GPU was three times faster than that on the CPU even when using a very low end GP-GPU device. The freely available VTK libraries have been used for the 3D processing and rendering. Hence any one could reproduce all this work at no additional cost. Since every thing has been developed from the ground up and no black boxes were used, it was easily possible to parallise the whole process to improve speed. Hence it was demonstrated that, Digital holography can be done entirely using open source software alone.