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SAVI: Synthetic apertures for long-range, subdiffraction-limited visible imaging using Fourier ptychography

View Article: PubMed Central - PubMed

ABSTRACT

Synthetic apertures for visible imaging are a promising approach to achieving subdiffraction resolution in long-distance imaging.

No MeSH data available.


Related in: MedlinePlus

Differences when recovering optically rough objects.Previous FP methods, particularly transmissive geometries, have assumed that the scene consists of smooth objects with a flat phase. Left: Simulation of recovering a smooth resolution target in a transmissive geometry, adapted from Holloway et al. (32). The recovered Fourier magnitude (shown on a log scale) follows a nicely structured pattern with a peak at the dc component and decaying magnitudes for high spatial frequencies. Right: Simulation of recovering a rough resolution target in a reflective geometry. Diffuse objects spread Fourier information more uniformly, and the Fourier magnitude does not exhibit any meaningful structure. The difference in Fourier patterns is evident in the captured images taken from the same locations in both modalities. The diffuse reflectance results in captured and reconstructed images that contain speckle.
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Figure 2: Differences when recovering optically rough objects.Previous FP methods, particularly transmissive geometries, have assumed that the scene consists of smooth objects with a flat phase. Left: Simulation of recovering a smooth resolution target in a transmissive geometry, adapted from Holloway et al. (32). The recovered Fourier magnitude (shown on a log scale) follows a nicely structured pattern with a peak at the dc component and decaying magnitudes for high spatial frequencies. Right: Simulation of recovering a rough resolution target in a reflective geometry. Diffuse objects spread Fourier information more uniformly, and the Fourier magnitude does not exhibit any meaningful structure. The difference in Fourier patterns is evident in the captured images taken from the same locations in both modalities. The diffuse reflectance results in captured and reconstructed images that contain speckle.

Mentions: The results presented in this paper also differ from previous works in one key regard. We demonstrate FP for optically rough surfaces, that is, surfaces that produce speckle. This is more conducive to imaging everyday objects that scatter incident light in random directions. In Fig. 2, a comparison with existing FP implementations is shown. Previous works have relied on smooth objects and are loosely represented by the transmissive data set adapted from Holloway et al. (32) shown on the left side of Fig. 2. A sample data set of a diffuse object collected in a reflection mode geometry is shown on the right. The immediate difference between the two data sets is that the random phase associated with diffuse objects effectively spreads out information across the entire Fourier domain. As a consequence of the random phase, the spatial information is obfuscated by the resultant speckle.


SAVI: Synthetic apertures for long-range, subdiffraction-limited visible imaging using Fourier ptychography
Differences when recovering optically rough objects.Previous FP methods, particularly transmissive geometries, have assumed that the scene consists of smooth objects with a flat phase. Left: Simulation of recovering a smooth resolution target in a transmissive geometry, adapted from Holloway et al. (32). The recovered Fourier magnitude (shown on a log scale) follows a nicely structured pattern with a peak at the dc component and decaying magnitudes for high spatial frequencies. Right: Simulation of recovering a rough resolution target in a reflective geometry. Diffuse objects spread Fourier information more uniformly, and the Fourier magnitude does not exhibit any meaningful structure. The difference in Fourier patterns is evident in the captured images taken from the same locations in both modalities. The diffuse reflectance results in captured and reconstructed images that contain speckle.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5392025&req=5

Figure 2: Differences when recovering optically rough objects.Previous FP methods, particularly transmissive geometries, have assumed that the scene consists of smooth objects with a flat phase. Left: Simulation of recovering a smooth resolution target in a transmissive geometry, adapted from Holloway et al. (32). The recovered Fourier magnitude (shown on a log scale) follows a nicely structured pattern with a peak at the dc component and decaying magnitudes for high spatial frequencies. Right: Simulation of recovering a rough resolution target in a reflective geometry. Diffuse objects spread Fourier information more uniformly, and the Fourier magnitude does not exhibit any meaningful structure. The difference in Fourier patterns is evident in the captured images taken from the same locations in both modalities. The diffuse reflectance results in captured and reconstructed images that contain speckle.
Mentions: The results presented in this paper also differ from previous works in one key regard. We demonstrate FP for optically rough surfaces, that is, surfaces that produce speckle. This is more conducive to imaging everyday objects that scatter incident light in random directions. In Fig. 2, a comparison with existing FP implementations is shown. Previous works have relied on smooth objects and are loosely represented by the transmissive data set adapted from Holloway et al. (32) shown on the left side of Fig. 2. A sample data set of a diffuse object collected in a reflection mode geometry is shown on the right. The immediate difference between the two data sets is that the random phase associated with diffuse objects effectively spreads out information across the entire Fourier domain. As a consequence of the random phase, the spatial information is obfuscated by the resultant speckle.

View Article: PubMed Central - PubMed

ABSTRACT

Synthetic apertures for visible imaging are a promising approach to achieving subdiffraction resolution in long-distance imaging.

No MeSH data available.


Related in: MedlinePlus