{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:42:15Z","timestamp":1760150535048,"version":"build-2065373602"},"reference-count":43,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2023,11,29]],"date-time":"2023-11-29T00:00:00Z","timestamp":1701216000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the National Natural Science Foundation of China","award":["61974064","61934004","92164201"],"award-info":[{"award-number":["61974064","61934004","92164201"]}]},{"name":"the National Key Research Program of China","award":["61974064","61934004","92164201"],"award-info":[{"award-number":["61974064","61934004","92164201"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>The development of a filterless imager has been eagerly awaited to overcome the diffraction limit when pixel sizes decrease to subwavelength scales. We propose an architecture for a filterless imager based on a symmetric inversely stacked radial junction (RJ) PINIP photodetector over silicon nanowires (SiNWs), whereby the diameter of which is less than 500 nm, which preliminarily displays the capability of bias-selected and tunable spectrum responses to the R, G, and B color bands. Assisted via suitably trained deep learning algorithms, the imager can provide more accurate color discrimination and imaging capabilities. Here, we used KNN (k-nearest neighbor) and convolution neural network (CNN) methods to retrieve the RGB ratios from the measured photocurrent value based on the pre-trained bias-tuned spectrum responses and reconstructed the images with high accuracy. Further, we demonstrated the capability of restoring sub-sampling pictures via CNN with a U-net architecture, and satisfactory reconstruction was obtained even with a sampling ratio as low as 20%. Our imaging scheme cannot only be used for high-resolution imaging but can also pave the way for application in single-pixel imaging and compressive sensing.<\/jats:p>","DOI":"10.3390\/sym15122127","type":"journal-article","created":{"date-parts":[[2023,11,29]],"date-time":"2023-11-29T09:00:18Z","timestamp":1701248418000},"page":"2127","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Color Sensing and Image Reconstruction Using Intelligent Machine Learning Algorithm with PINIP Radial Junction Imager"],"prefix":"10.3390","volume":"15","author":[{"given":"Yifei","family":"Zhang","sequence":"first","affiliation":[{"name":"School of Electronics Science and Engineering, Nanjing University, Nanjing 210023, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zongsen","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Electronics Science and Engineering, Nanjing University, Nanjing 210023, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shaobo","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Physical Science and Technology, Yangzhou University, Yangzhou 225002, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Junzhuan","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Electronics Science and Engineering, Nanjing University, Nanjing 210023, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2524","DOI":"10.1364\/OL.38.002524","article-title":"Compressive holography with a single-pixel detector","volume":"38","author":"Clemente","year":"2013","journal-title":"Opt. 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