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Light field (LF) is a 4-D function representing the light radiance in free space in terms of rays. A dense grid of cameras, parameterized by two planes, captures an LF: the sensor plane and the focal plane. Multi-camera images stack in volumes, and when sliced, form epipolar plane images (EPI). In EPI, lines with the same slope represent object points at the same scene depth. Thus, the synthesis of new views can be formulated as a problem of interpolation in EPI domain. In this contribution, we propose a three-pass algorithm for LF interpolation in EPI domain. Each EPI is sheared by a factor determined by the dominant slope, employing fast DCT-based fractional shifts. In sheared EPI, dominant lines appear vertical and can be easily interpolated. 'De-shearing' reconstructs EPI's original geometry. We analyze the performance of the proposed LF interpolation in Fourier domain and illustrate it with examples of virtual view synthesis from dense multi-camera imagery.

A new DCT-based algorithm for signal and image scaling by arbitrary factor is presented. The algorithm is virtually free of boundary effects and implements the discrete sinc-interpolation, which preserves the spectral content of the signal, and therefore is free from interpolation errors. Being implemented through the fast FFT-type DCT algorithm, the scaling algorithm has computational complexity of O(log[σ N ]) operations per output sample, where N and [σ N ] are number of signal input and output samples, correspondingly.

Results of comparative study of the computational complexity of different algorithms for numerical reconstruction of electronically recorded holograms are presented and discussed. The following algorithms were compared: different types of Fourier and convolutional algorithms and a new universal DCT-based algorithm, in terms of the number of operations. Based on the comparison results, the feasibility of real-time implementation of numerical reconstruction of holograms is evaluated.