{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,10,24]],"date-time":"2023-10-24T06:10:30Z","timestamp":1698127830046},"reference-count":8,"publisher":"Wiley","issue":"11","license":[{"start":{"date-parts":[[2007,3,21]],"date-time":"2007-03-21T00:00:00Z","timestamp":1174435200000},"content-version":"vor","delay-in-days":5558,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Systems &amp; Computers in Japan"],"published-print":{"date-parts":[[1992,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>As a method to reconstruct the surface shape from its shading images, a new approach is presented. This approach recovers the surface gradients of an object from three images obtained by varying the illuminating direction only in the azimuth angle direction.<\/jats:p><jats:p>This paper shows that the gradient parameters can be determined uniquely from the information of input image density and its directional derivatives which are obtained by varying the illuminating directions only in the azimuth directions. The method assumes that the object is a Lambertian surface.<\/jats:p><jats:p>Parameters of the illuminating direction consist of the azimuth angle and zenith angle. It is shown also that the zenith angle can be recovered analytically by using the information of image densities corresponding to more than two surface elements. Several errors are evaluated for some curved or polyhedral objects by computer simulations. These are obtained by the approximation of the directional derivatives with numerical difference or the quantization of the input image densities, and applicable conditions are shown.<\/jats:p>","DOI":"10.1002\/scj.4690231108","type":"journal-article","created":{"date-parts":[[2007,7,7]],"date-time":"2007-07-07T21:52:56Z","timestamp":1183845176000},"page":"85-95","source":"Crossref","is-referenced-by-count":0,"title":["Unidirectional photometric flow fields under illuminating directions with slightly varied azimuth angles"],"prefix":"10.1002","volume":"23","author":[{"given":"Hidekazu","family":"Tanaka","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuji","family":"Iwahori","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Naohiro","family":"Ishii","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2007,3,21]]},"reference":[{"key":"e_1_2_1_2_2","first-page":"115","volume-title":"The Psychology of Computer Vision","author":"Horn B. K. P.","year":"1975"},{"key":"e_1_2_1_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/0004-3702(77)90020-0"},{"key":"e_1_2_1_4_2","doi-asserted-by":"publisher","DOI":"10.1117\/12.7972479"},{"issue":"7","key":"e_1_2_1_5_2","first-page":"842","article-title":"Determining 3\u2010D shape from 2\u2010D shading information based on the reflectance map technique","volume":"65","author":"Ikeuchi K.","year":"1982","journal-title":"Trans. I.E.I.C.E., Japan"},{"issue":"3","key":"e_1_2_1_6_2","first-page":"427","article-title":"A method to reconstruct shape and position of 3\u2010D objects using photometric stereo system","volume":"69","author":"Hong H.","year":"1982","journal-title":"Trans. I.E.I.C.E., Japan"},{"issue":"1","key":"e_1_2_1_7_2","first-page":"110","article-title":"Extended photometric stereo for an object with unknown reflectance property","volume":"71","author":"Iwahori Y.","year":"1988","journal-title":"Trans. I.E.I.C.E., Japan"},{"issue":"3","key":"e_1_2_1_8_2","first-page":"321","article-title":"Photometric stereo under illumination from unknown zenith angles","volume":"74","author":"Iwahori Y.","year":"1991","journal-title":"Trans. I.E.I.C.E., Japan"},{"key":"e_1_2_1_9_2","first-page":"46","volume-title":"Shape understanding from Lambertian photometric flow fields","author":"Wollf L. B.","year":"1989"}],"container-title":["Systems and Computers in Japan"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fscj.4690231108","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/scj.4690231108","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T11:49:46Z","timestamp":1698061786000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/scj.4690231108"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,1]]},"references-count":8,"journal-issue":{"issue":"11","published-print":{"date-parts":[[1992,1]]}},"alternative-id":["10.1002\/scj.4690231108"],"URL":"https:\/\/doi.org\/10.1002\/scj.4690231108","archive":["Portico"],"relation":{},"ISSN":["0882-1666","1520-684X"],"issn-type":[{"value":"0882-1666","type":"print"},{"value":"1520-684X","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,1]]}}}