Comparison of numerical image reconstruction methods in holography

In favour of the reconstruction of the real or virtual image's phase and intensity, the complete digital holographic images are being processed. This reconstruction takes place with the numerical definition of the diffraction integral. One of the possible realization is the Fresnel approximation, which employs a sole Fourier-transformation. Another method is to interpret the diffraction formula as a convolution integral, and if we calculate the formula, it will be doubled or tripled because of the transformation. The impulse response of wave fields should be represented in this convolution approach, from which the Fourier transform can be immediately determined. The impulse response as well as the Fourier transform can be immediately specified, or well approximated. The essential distinction between the Fresnel and convolution approach is the different size of resultant images. Furthermore, this size in case of the Fresnel process depends on the distance of the object and the sensor, as well as the wavelength of the illuminating light; but in the other case, it is invalid.