Fast Extended Depth-of-Field Reconstruction for Complex Holograms Using Block Partitioned Entropy Minimization
Optical scanning holography (OSH) is a powerful and effective method for capturing the complex hologram of a three-dimensional (3-D) scene. Such captured complex hologram is called optical scanned hologram. However, reconstructing a focused image from an optical scanned hologram is a difficult issue...
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-05-01
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| Series: | Applied Sciences |
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| Online Access: | http://www.mdpi.com/2076-3417/8/5/830 |
| _version_ | 1818543151847047168 |
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| author | Peter Wai Ming Tsang Ting-Chung Poon Jung-Ping Liu |
| author_facet | Peter Wai Ming Tsang Ting-Chung Poon Jung-Ping Liu |
| author_sort | Peter Wai Ming Tsang |
| collection | DOAJ |
| description | Optical scanning holography (OSH) is a powerful and effective method for capturing the complex hologram of a three-dimensional (3-D) scene. Such captured complex hologram is called optical scanned hologram. However, reconstructing a focused image from an optical scanned hologram is a difficult issue, as OSH technique can be applied to acquire holograms of wide-view and complicated object scenes. Solutions developed to date are mostly computationally intensive, and in so far only reconstruction of simple object scenes have been demonstrated. In this paper we report a low complexity method for reconstructing a focused image from an optical scanned hologram that is representing a 3-D object scene. Briefly, a complex hologram is back-propagated onto regular spaced images along the axial direction, and from which a crude, blocky depth map of the object scene is computed according to non-overlapping block partitioned entropy minimization. Subsequently, the depth map is low-pass filtered to decrease the blocky distribution, and employed to reconstruct a single focused image of the object scene for extended depth of field. The method proposed here can be applied to any complex holograms such as those obtained from standard phase-shifting holography. |
| first_indexed | 2024-12-11T22:31:34Z |
| format | Article |
| id | doaj.art-de58af1016734d73a9969f07b78b9b22 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-12-11T22:31:34Z |
| publishDate | 2018-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-de58af1016734d73a9969f07b78b9b222022-12-22T00:48:08ZengMDPI AGApplied Sciences2076-34172018-05-018583010.3390/app8050830app8050830Fast Extended Depth-of-Field Reconstruction for Complex Holograms Using Block Partitioned Entropy MinimizationPeter Wai Ming Tsang0Ting-Chung Poon1Jung-Ping Liu2Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, ChinaBradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA 24061, USADepartment of Photonics, Feng Chia University, No. 100 Wenhwa Rd., Taichung 40724, TaiwanOptical scanning holography (OSH) is a powerful and effective method for capturing the complex hologram of a three-dimensional (3-D) scene. Such captured complex hologram is called optical scanned hologram. However, reconstructing a focused image from an optical scanned hologram is a difficult issue, as OSH technique can be applied to acquire holograms of wide-view and complicated object scenes. Solutions developed to date are mostly computationally intensive, and in so far only reconstruction of simple object scenes have been demonstrated. In this paper we report a low complexity method for reconstructing a focused image from an optical scanned hologram that is representing a 3-D object scene. Briefly, a complex hologram is back-propagated onto regular spaced images along the axial direction, and from which a crude, blocky depth map of the object scene is computed according to non-overlapping block partitioned entropy minimization. Subsequently, the depth map is low-pass filtered to decrease the blocky distribution, and employed to reconstruct a single focused image of the object scene for extended depth of field. The method proposed here can be applied to any complex holograms such as those obtained from standard phase-shifting holography.http://www.mdpi.com/2076-3417/8/5/830optical scanning holographyextended depth-of-fieldautomatic focus detectionentropy minimizationblock partitioned entropy minimization |
| spellingShingle | Peter Wai Ming Tsang Ting-Chung Poon Jung-Ping Liu Fast Extended Depth-of-Field Reconstruction for Complex Holograms Using Block Partitioned Entropy Minimization Applied Sciences optical scanning holography extended depth-of-field automatic focus detection entropy minimization block partitioned entropy minimization |
| title | Fast Extended Depth-of-Field Reconstruction for Complex Holograms Using Block Partitioned Entropy Minimization |
| title_full | Fast Extended Depth-of-Field Reconstruction for Complex Holograms Using Block Partitioned Entropy Minimization |
| title_fullStr | Fast Extended Depth-of-Field Reconstruction for Complex Holograms Using Block Partitioned Entropy Minimization |
| title_full_unstemmed | Fast Extended Depth-of-Field Reconstruction for Complex Holograms Using Block Partitioned Entropy Minimization |
| title_short | Fast Extended Depth-of-Field Reconstruction for Complex Holograms Using Block Partitioned Entropy Minimization |
| title_sort | fast extended depth of field reconstruction for complex holograms using block partitioned entropy minimization |
| topic | optical scanning holography extended depth-of-field automatic focus detection entropy minimization block partitioned entropy minimization |
| url | http://www.mdpi.com/2076-3417/8/5/830 |
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