Noise reduction for digital holograms in a discrete cosine transform (DCT) domain

This paper presents a method for reducing noise in a digital hologram, which occurs during acquisition. The algorithm proposed initially transforms a digital hologram into frequency-domain data through a discrete cosine transform (DCT), and separates the object from the background in the transformed image. As a noise reduction method, a histogram modification method is applied to the object, while the background is substituted with zero values. Experimental results showed that the proposed scheme improves the visual image quality very much when reconstructed by both the optical system and the PC simulation.