| 1. Identity statement | |
| Reference Type | Conference Paper (Conference Proceedings) |
| Site | sibgrapi.sid.inpe.br |
| Holder Code | ibi 8JMKD3MGPEW34M/46T9EHH |
| Identifier | 6qtX3pFwXQZeBBx/GGUru |
| Repository | sid.inpe.br/banon/2005/07.09.13.12 |
| Last Update | 2005:07.09.03.00.00 (UTC) administrator |
| Metadata Repository | sid.inpe.br/banon/2005/07.09.13.12.22 |
| Metadata Last Update | 2022:06.14.00.12.56 (UTC) administrator |
| DOI | 10.1109/SIBGRAPI.2005.47 |
| Citation Key | TorreãoFern:2005:SiShDe |
| Title | Single-image shape from defocus  |
| Format | On-line |
| Year | 2005 |
| Access Date | 2024, Apr. 28 |
| Number of Files | 1 |
| Size | 139 KiB |
| 2. Context | |
| Author | 1 Torreão, José Ricardo de Almeida 2 Fernandes, João Luiz |
| Affiliation | 1 Instituto de Computação, Universidade Federal Fluminense |
| Editor | Rodrigues, Maria Andréia Formico Frery, Alejandro César |
| e-Mail Address | jrat@ic.uff.br |
| Conference Name | Brazilian Symposium on Computer Graphics and Image Processing, 18 (SIBGRAPI) |
| Conference Location | Natal, RN, Brazil |
| Date | 9-12 Oct. 2005 |
| Publisher | IEEE Computer Society |
| Publisher City | Los Alamitos |
| Book Title | Proceedings |
| Tertiary Type | Full Paper |
| History (UTC) | 2008-07-17 14:10:59 :: jrat -> banon :: 2008-08-26 15:17:01 :: banon -> administrator :: 2009-08-13 20:37:46 :: administrator -> banon :: 2010-08-28 20:01:17 :: banon -> administrator :: 2022-06-14 00:12:56 :: administrator -> :: 2005 |
| 3. Content and structure | |
| Is the master or a copy? | is the master |
| Content Stage | completed |
| Transferable | 1 |
| Version Type | finaldraft |
| Keywords | shape from defocus shape from shading |
| Abstract | The limited depth of field causes scene points at various distances from a camera to be imaged with different amounts of defocus. If images captured under different aperture settings are available, the defocus measure can be estimated and used for 3D scene reconstruction. Usually, defocusing is modeled by gaussian convolution over local image patches, but the estimation of a defocus measure based on that is hampered by the spurious high-frequencies introduced by windowing. Here we show that this can be ameliorated by the use of unnormalized gaussians, which allow defocus estimation from the zero-frequency Fourier component of the image patches, thus avoiding spurious high frequencies. As our main contribution, we also show that the modified shape from defocus approach can be extended to shape estimation from single shading inputs. This is done by simulating an aperture change, via gaussian convolution, in order to generate the second image required for defocus estimation. As proven here, the gaussian-blurred image carries an explicit depth-dependent blur component - which is missing from an ideal shading input -, and thus allows depth estimation as in the multi-image case. |
| Arrangement 1 | urlib.net > SDLA > Fonds > SIBGRAPI 2005 > Single-image shape from... |
| Arrangement 2 | urlib.net > SDLA > Fonds > Full Index > Single-image shape from... |
| doc Directory Content | access |
| source Directory Content | there are no files |
| agreement Directory Content | there are no files |
| 4. Conditions of access and use | |
| data URL | http://urlib.net/ibi/6qtX3pFwXQZeBBx/GGUru |
| zipped data URL | http://urlib.net/zip/6qtX3pFwXQZeBBx/GGUru |
| Language | en |
| Target File | torreaoj_defocus.pdf |
| User Group | jrat administrator |
| Visibility | shown |
| 5. Allied materials | |
| Next Higher Units | 8JMKD3MGPEW34M/46R3ED5 8JMKD3MGPEW34M/4742MCS |
| Citing Item List | sid.inpe.br/sibgrapi/2022/05.05.04.08 10 sid.inpe.br/banon/2001/03.30.15.38.24 1 |
| Host Collection | sid.inpe.br/banon/2001/03.30.15.38 |
| 6. Notes | |
| Empty Fields | archivingpolicy archivist area callnumber contenttype copyholder copyright creatorhistory descriptionlevel dissemination documentstage edition electronicmailaddress group isbn issn label lineage mark mirrorrepository nextedition notes numberofvolumes orcid organization pages parameterlist parentrepositories previousedition previouslowerunit progress project readergroup readpermission resumeid rightsholder schedulinginformation secondarydate secondarykey secondarymark secondarytype serieseditor session shorttitle sponsor subject tertiarymark type url volume |