September 2017
Spotlight Summary by Pascal Picart
Color-image reconstruction for two-wavelength digital holography using a generalized phase-shifting approach
Digital color holography exhibits a high potential to record and image 3D object scenes. Although the recording process can be simplified and built with cheap and on-the-shelf components, the complexity of the digital processing needs to be increased in order to enhance the reconstructed image quality. In particular, cross-talk from the color sensor and phase-shift nonlinearity need to be evaluated and compensated for the final image reconstruction. Here, phase-shifting digital color holography is significantly improved by addressing the main limitations of the technique. First, the color cross-talk from a classical color sensor (Bayer mosaic) is evaluated using a contrast method for three wavelengths. In this way, compensation of color cross-talk is less sensitive to dark-current noise. Second, using a generalized phase-shifting approach, the phase-shifting process does not require any calibration step or precise knowledge of the phase-shift amount. An arbitrary phase shift is used to overcome the wavelength-dependence of the phase-shift. The method permits accurate retrieval of the object field for each monochrome hologram. Last, a single Fourier transform image-reconstruction method is proposed for a color-image synthesis that can adjust the size of the reconstructed images for all wavelengths. Experiments demonstrate the validity of the proposed method, which yields color reconstructed images without chromatic aberration.
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Article Information
Color-image reconstruction for two-wavelength digital holography using a generalized phase-shifting approach
Takaaki Shiratori, Keisuke Kasai, and Nobukazu Yoshikawa
Appl. Opt. 56(23) 6554-6563 (2017) View: HTML | PDF