Numerical twin image suppression by nonlinear segmentation mask in digital holography

Abstract

The in-line holography has obvious advantages especially in wider spatial bandwidth over the off-axis holography. However, a direct current(DC)-noise and an unwanted twin image should be separated or eliminated in the in-line holography for a high quality reconstruction. An approach for suppressing the twin image is proposed by separating the real and twin image regions in the digital holography. Specifically, the initial region of real and twin images is obtained by a blind separation matrix, and the segmentation mask to suppress the twin image is calculated by nonlinear quantization from the segmented image. For the performance evaluation, the proposed method is compared with the existing approaches including the overlapping block variance and manual-based schemes. Experimental results showed that the proposed method has a better performance at the overlapped region of the real and twin images. Additionally, the proposed method causes less loss of real image than the overlapping block variance-based scheme. Therefore, we believe that the proposed scheme can be a useful tool for high quality reconstruction in the in-line holography.

Twin-image problem in digital holography—a survey (Invited Paper)

“…Separation of the real and twin image regions by a blind separation matrix and suppression of the twin image by the segmentation mask is proposed in Ref. [107]. The approach gives better result than the overlapping block variance and manual-based schemes for outlining the image regions.…”

Laplace Operation-Based DC Noise Reduction in Digital Holography

“…Similarly, E R is a reference wave with amplitude a R and phase ϕ R . A holographic fringe pattern, which is the interference pattern between the object and reference wave, is obtained by the intensity of interference [3] as…”

“…The off-axis holography gives a better reconstruction with negligible noise than the inline holography. However, the available bandwidth of off-axis holography is restricted by the tilted reference wave [3], [4]. On the other hand, the in-line holography has obvious advantages in holographic reconstruction.…”

“…The typical unwanted components Manuscript are twin image (conjugate image) and direct-current (DC) noise. The unwanted twin image and the noise in the numerical reconstruction of a holographic fringe pattern should be removed for high quality reconstruction and its applications [3], [4]. In this work, the DC-noise reduction methods [4]- [6] generally used in the digital holography are first described in Section II, and then the proposed DC-noise reduction scheme is numerically explained in Section III followed by experimental result comparisons with state-of-arts in Section IV.…”

Compact lensless phase imager

“…This is known as "the twin image problem". Several methods have been investigated to remove this twin image in order to be able to reconstruct the phase of the object along with its amplitude [13][14][15][16][17][18].…”