Performance Evaluation of Phase-Only Technique for High-Resolution Holographic Imaging

Abstract

Phase-only image reconstruction is a widely used technique in holography. It utilizes only the phase information of the complex amplitude of the resultant wave-field for image formation. In many cases, the phase-only approach is advantageous over conventional methods in terms of data acquisition, storage, and computation complexity. In addition, it is capable of high-resolution imaging at extremely low bit-rates.

However, the resolving capability of the phase-only technique has been demonstrated for only the cases that the sources are consisting of a few point scatters or are limited to small localized regions. Suggestions are made that the performance and limitation of the phase-only method should be evaluated for generalized cases.

The purpose of this paper is to provide a quantitative performance evaluation of the phase-only imaging technique. We will first introduce the formulation to measure the estimation error of the phase-only method in both source and wave-field domains. Then we perform the error analysis and compare the resolving capability of image reconstructions by amplitude-only method as well as the standard backward propagation of the complete wave-field information. This approach for performance evaluation cannot only be used to predict image quality and limitations of phase-only or amplitude-only methods, but also be applied to optimize wave-field signal representation and quantization bit-rate distribution.