Wojciech Chojnacki

Professor Wojciech Chojnacki

Adjunct Professor

School of Mathematical Sciences

College of Science

Year Citation
2025 Chojnacki, W. (2025). Vector-valued Banach limits and the linear span property. Aequationes Mathematicae, 99(4), 1657-1674.
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2025 Chojnacki, W. (2025). Correction to: Vector-valued Banach limits and the linear span property (Aequationes mathematicae, (2025), 99, 4, (1657-1674), 10.1007/s00010-024-01140-7). Aequationes Mathematicae, 99(4), 2025.
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2022 Bobrowski, A., & Chojnacki, W. (2022). Isolated points of spaces of homomorphisms from ordered AL-algebras. DISSERTATIONES MATHEMATICAE, 577, 4-69.
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2021 Chojnacki, W. (2021). A note on crossed products. Expositiones Mathematicae, 39(1), 115-128.
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2020 Chojnacki, W., Szpak, Z. L., & Wadenbäck, M. (2020). The equivalence of two definitions of compatible homography matrices. Pattern Recognition Letters, 135, 38-43.
DOI Scopus3 WoS2
2019 Chojnacki, W., & Szpak, Z. L. (2019). Determining ellipses from low-resolution images with a comprehensive image formation model. Journal of the Optical Society of America A, 36(2), 212-233.
DOI Scopus2 WoS2
2016 Chojnacki, W. (2016). Around Schwenninger and Zwart’s zero-two law for cosine families. Archiv der Mathematik, 106(6), 561-571.
DOI Scopus4 WoS4
2015 Szpak, Z., Chojnacki, W., & van den Hengel, A. (2015). Guaranteed ellipse fitting with a confidence region and an uncertainty measure for centre, axes, and orientation. Journal of Mathematical Imaging and Vision, 52(2), 173-199.
DOI Scopus43 WoS40
2015 Chojnacki, W. (2015). On cosine families close to scalar cosine families. Journal of the Australian Mathematical Society, 99(2), 166-174.
DOI Scopus11 WoS10
2015 Chojnacki, W., Szpak, Z., Brooks, M., & van Den Hengel, A. (2015). Enforcing consistency constraints in uncalibrated multiple homography estimation using latent variables. Machine Vision and Applications, 26(2-3), 401-422.
DOI Scopus5 WoS4
2015 Bobrowski, A., Chojnacki, W., & Gregosiewicz, A. (2015). On close-to-scalar one-parameter cosine families. Journal of Mathematical Analysis and Applications, 429(1), 383-394.
DOI Scopus10 WoS9
2014 Quoc, H., Chin, T., Chojnacki, W., & Suter, D. (2014). Sampling minimal subsets with large spans for robust estimation. International Journal of Computer Vision, 106(1), 93-112.
DOI Scopus27 WoS27
2014 Szpak, Z., Chojnacki, W., Eriksson, A., & van den Hengel, A. (2014). Sampson distance based joint estimation of multiple homographies with uncalibrated cameras. Computer Vision and Image Understanding, 125, 200-213.
DOI Scopus21 WoS17
2013 Bobrowski, A., & Chojnacki, W. (2013). Cosine families and semigroups really differ. Journal of Evolution Equations, 13(4), 897-916.
DOI Scopus11 WoS11
2013 Bobrowski, A., & Chojnacki, W. (2013). Isolated points of some sets of bounded cosine families, bounded semigroups, and bounded groups on a Banach space. Studia Mathematica, 217(3), 219-241.
DOI Scopus12 WoS11
2013 Chojnacki, W., & Van Den Hengel, A. (2013). On the dimension of the set of two-view multi-homography matrices. Complex Analysis and Operator Theory, 7(2), 465-484.
DOI Scopus4 WoS5
2011 Chojnacki, W. (2011). On uniformly bounded spherical functions in Hilbert space. Aequationes Mathematicae, 81(1-2), 135-154.
DOI Scopus5 WoS4
2010 Chojnacki, W. (2010). On operator-valued cosine sequences on UMD spaces. Studia Mathematica, 199(3), 267-278.
DOI Scopus5 WoS5
2009 Chojnacki, W., & Brooks, M. (2009). A note on the locally linear embedding algorithm. International Journal of Pattern Recognition and Artificial Intelligence, 23(8), 1739-1752.
DOI Scopus15 WoS8
2008 Chojnacki, W. (2008). Some monotonicity and limit results for the regularised incomplete gamma function. Annales Polonici Mathematici, 94(3), 283-291.
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2008 Scoleri, T., Chojnacki, W., & Brooks, M. (2008). Dimensionality reduction for more stable vision parameter estimation. IET Computer Vision, 2(4), 218-227.
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2007 Chojnacki, W. (2007). On group decompositions of bounded cosine sequences. Studia Mathematica, 181(1), 61-85.
DOI Scopus15 WoS9
2007 Chojnacki, W., & Brooks, M. (2007). On the consistency of the normalized eight-point algorithm. Journal of Mathematical Imaging and Vision, 28(1), 19-27.
DOI Scopus9 WoS7
2007 Baron, K., Chojnacki, W., & Jarczyk, W. (2007). Continuity of solutions of the translation equation. Aequationes Mathematicae, 74(3), 314-317.
DOI Scopus7
2005 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2005). FNS, CFNS and HEIV: A unifying approach. Journal of Mathematical Imaging and Vision, 23(2), 175-183.
DOI Scopus28 WoS19
2004 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2004). From FNS to HEIV: A link between two vision parameter estimation methods. IEEE Transactions on Pattern Analysis and Machine Intelligence, 26(2), 264-268.
DOI Scopus28 WoS24 Europe PMC3
2004 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2004). A new constrained parameter estimator for computer vision applications. Image and Vision Computing, 22(2), 85-91.
DOI Scopus34 WoS24
2003 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2003). Revisiting Hartley's normalized eight-point algorithm. IEEE Transactions on Pattern Analysis and Machine Intelligence, 25(9), 1172-1177.
DOI Scopus60 WoS47
2002 Chojnacki, W. (2002). A generalization of the Widder-Arendt theorem. Proceedings of the Edinburgh Mathematical Society, 45(1), 161-179.
DOI Scopus7 WoS7
2001 Chojnacki, W., Brooks, M., & Van Den Hengel, A. (2001). Rationalising the renormalisation method of Kanatani. Journal of Mathematical Imaging and Vision, 14(1), 21-38.
DOI Scopus45 WoS37
2000 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2000). On the fitting of surfaces to data with covariances. IEEE Transactions on Pattern Analysis and Machine Intelligence, 22(11), 1294-1303.
DOI Scopus150 WoS121
2000 Kanatani, K., Shimizu, Y., Ohta, N., Brooks, M., Chojnacki, W., & Van Den Hengel, A. (2000). Fundamental matrix from optical flow: optimal computation and reliability evaluation. Journal of Electronic Imaging, 9(2), 194-202.
DOI Scopus12 WoS8
1999 Chojnacki, W. (1999). A characterisation of the circle group. Collectanea Mathematica, 50(3), 303-310.
1999 Chojnacki, W. (1999). Multiplier algebras, Banach bundles, and one-parameter semigroups. Annali Della Scuola Normale Superiore Di Pisa, Classe Di Scienze, Serie 4, 28(2), 287-322.
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1998 Chojnacki, W., & Kisynski, J. (1998). On the Favard classes of semigroups associated with pseudo-resolvents. Acta Scientiarum Mathematicarum, 64(3-4), 681-696.
1998 Chojnacki, W., Brooks, M., & Gibbins, D. (1998). On the feasibility of determining light-source direction from an image. Quarterly of Applied Mathematics, 56(2), 289-307.
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1998 Chojnacki, W. (1998). On the Equivalence of a Theorem of Kisynski and the Hille-Yosida Generation Theorem. Proceedings of the American Mathematical Society, 126(2), 491-497.
DOI Scopus10 WoS9
1998 Chojnacki, W. (1998). A new proof of a theorem concerning decomposable groups. Glasnik Matematicki, 33(1), 13-17.
1997 Brooks, M., Chojnacki, W., & Baumela, L. (1997). Determining the egomotion of an uncalibrated camera from instantaneous optical flow. Journal of the Optical Society of America A, 14(10), 2670-2677.
DOI Scopus37 WoS29
1997 Chojnacki, W., Brooks, M., & Gibbins, D. (1997). Can the Sun's Direction be Estimated from an Image Prior to the Computation of Object Shape?. Journal of Mathematical Imaging and Vision, 7(2), 139-147.
DOI Scopus4 WoS3
1996 Chojnacki, W. (1996). Group representations of bounded cosine functions. Journal für die reine und angewandte Mathematik, 478(478), 61-84.
DOI Scopus17 WoS15
1995 Chojnacki, W. (1995). A note on complete integrals. Proceedings of the American Mathematical Society, 123(2), 393-401.
DOI Scopus2 WoS2
1994 Chojnacki, W., Brooks, M. J., & Gihhins, D. (1994). Revisiting pentland’s estimator of light source direction. Journal of the Optical Society of America A Optics and Image Science and Vision, 11(1), 118-124.
DOI Scopus31 WoS27
1992 Brooks, M. J., Chojnacki, W., & Kozera, R. (1992). Impossible and ambiguous shading patterns. International Journal of Computer Vision, 7(2), 119-126.
DOI Scopus33 WoS29
1992 Brooks, M. J., Chojnacki, W., & Kozera, R. (1992). Circularly symmetric eikonal equations and non-uniqueness in computer vision. Journal of Mathematical Analysis and Applications, 165(1), 192-215.
DOI Scopus15 WoS15
1992 BROOKS, M. J., CHOJNACKI, W., & KOZERA, R. (1992). SHADING WITHOUT SHAPE. QUARTERLY OF APPLIED MATHEMATICS, 50(1), 27-38.
DOI WoS16
1992 Chojnacki, W. (1992). A generalized spectral duality theorem. Communications in Mathematical Physics, 143(3), 527-544.
DOI Scopus9 WoS6
1991 Chojnacki, W. (1991). Eigenvalues of almost periodic Schrödinger operators in L<sup>2</sup>(bℝ) are at most double. Letters in Mathematical Physics, 22(1), 7-10.
DOI Scopus6 WoS5
1991 Chojnacki, W. (1991). Lifting Fourier-Stieltjes transforms and transferring cocycles. Hokkaido Mathematical Journal, 20(3), 503-518.
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1991 GIBBINS, D., BROOKS, M. J., & CHOJNACKI, W. (1991). LIGHT-SOURCE DIRECTION FROM A SINGLE IMAGE - A PERFORMANCE ANALYSIS. AUSTRALIAN COMPUTER JOURNAL, 23(4), 165-174.
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1990 Chojnacki, W. (1990). On some totally ergodic functions. Pacific Journal of Mathematics, 144(1), 1-14.
DOI Scopus1 WoS2
1988 Chojnacki, W. (1988). On some holomorphic dynamical systems. Quarterly Journal of Mathematics, 39(2), 159-172.
DOI Scopus1 WoS1
1988 Chojnacki, W. (1988). Some non-trivial cocycles. Journal of Functional Analysis, 77(1), 9-31.
DOI Scopus3 WoS2
1987 Chojnacki, W. (1987). Cocycles and Almost Periodicity. Journal of the London Mathematical Society, s2-35(1), 98-108.
DOI Scopus1 WoS1
1986 Chojnacki, W. (1986). Almost periodic Schrödinger operators in L<sup>2</sup>(bR) whose point spectrum is not all of the spectrum. Journal of Functional Analysis, 65(2), 236-242.
DOI Scopus5 WoS4
1986 CHOJNACKI, W. (1986). BOUNDED HILBERT COSINUS FUNCTIONS IN COMMUTATIVE LOCALLY-COMPACT GROUPS. COMPOSITIO MATHEMATICA, 57(1), 15-60.
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Year Citation
2019 Chojnacki, W., & Szpak, Z. L. (2019). Full explicit consistency constraints in uncalibrated multiple homography estimation. In Proceedings of the 14th Asian Conference on Computer Vision (ACCV 2018), as published in Lecture Notes in Computer Science Vol. 11361 (pp. 659-675). Cham, Switzerland: Springer.
DOI Scopus1
2018 Chojnacki, W., & Szpak, Z. L. (2018). Full Explicit Consistency Constraints in Uncalibrated Multiple Homography Estimation.. In C. V. Jawahar, H. Li, G. Mori, & K. Schindler (Eds.), ACCV (1) Vol. 11361 (pp. 659-675). Springer.
2015 Szpak, Z., Chojnacki, W., & Van Den Hengel, A. (2015). Robust multiple homography estimation: an ill-solved problem. In Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition Vol. 07-12-June-2015 (pp. 2132-2141). Boston, MA: IEEE.
DOI Scopus17 WoS14
2015 Faulkner, H., Shehu, E., Szpak, Z., Chojnacki, W., Tapamo, J., Dick, A., & Van Den Hengel, A. (2015). A study of the region covariance descriptor: impact of feature selection and image transformations. In Proceedings of the International Conference on Digital Image Computing: Techniques and Applications (pp. 1-8). Adelaide, SA.: IEEE.
DOI Scopus6
2015 Chojnacki, W., Fabich, S., & Rutkowski, T. (2015). The construction of shafts in the copper fields in the conditions of the fore-sudetic monocline as exemplified by the SW-4 shaft. In Vertical and Decline Shaft Sinking Proceedings of the International Mining Forum 2015 (pp. 115-130). CRC Press.
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2012 Szpak, Z., Chojnacki, W., & Van Den Hengel, A. (2012). A comparison of ellipse fitting methods and implications for multiple-view geometry estimation. In Proceedings of Digital Image Computing Techniques and Applications, DICTA 2012 (pp. 1-8). USA: IEEE.
DOI Scopus12
2012 Szpak, Z., Chojnacki, W., & Van Den Hengel, A. (2012). Guaranteed ellipse fitting with the Sampson distance. In Proceedings of the12th European Conference on Computer Vision, ECCV 2012 Vol. 7576 LNCS (pp. 87-100). Germany: Springer-Verlag.
DOI Scopus44 WoS34
2011 Chojnacki, W., & Van Den Hengel, A. (2011). A dimensionality result for multiple homography matrices. In 2011 IEEE International Conference on Computer Vision (pp. 2104-2109). 345 E 47TH ST, NEW YORK, NY 10017 USA: IEEE.
DOI Scopus5 WoS4
2010 Chojnacki, W., Szpak, Z., Brooks, M., & Van Den Hengel, A. (2010). Multiple homography estimation with full consistency constraints. In Proceedings of DICTA 2010 (pp. 480-485). USA: IEEE.
DOI Scopus10
2009 Chojnacki, W., Hill, R., Van Den Hengel, A., & Brooks, M. (2009). Multi-projective Parameter Estimation for Sets of Homogeneous Matrices. In Proceedings of 2009 Digital Image Computing: Techniques and Applications (pp. 119-124). California: IEEE.
DOI Scopus2 WoS1
2007 Chojnacki, W., & Brooks, M. (2007). A consistency result for the normalized eight-point algorithm. In Rita Cucchiara (Ed.), Proceedings of the 14th International Conference on Image Analysis and Processing (pp. 1-6). USA: IEEE.
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2007 Scoleri, T., Chojnacki, W., & Brooks, M. (2007). A decoupled algorithm for vision parameter estimation with application to the trifocal tensor. In M. Bottema (Ed.), Proceedings of DICTA 2007 (pp. 138-143). CDROM: IEEE.
DOI Scopus2
2007 Van Den Hengel, A., Chojnacki, W., & Brooks, M. (2007). Determining the translational speed of a camera from time-varying optical flow. In B. Jahne (Ed.), Complex motion [electronic resource]: first international workshop, IWCM 2004, Gunzburg, Germany, October 12-14, 2004: revised papers Vol. 3417 LNCS (pp. 1-8). Germany: Springer.
DOI Scopus2 WoS2
2007 Chojnacki, W., van den Hengel, A., & Brooks, M. J. (2007). Generalised Principal Component Analysis: exploiting inherent parameter constraints. In J. Braz, A. Ranchordas, H. Araujo, & J. Jorge (Eds.), Advances in computer graphics and computer vision: International Conferences VISAPP and GRAPP 2006 Vol. 4 CCIS (pp. 217-228). Setubal, Portugal: Springer.
DOI Scopus2 WoS1
2006 Chojnacki, W., Van Den Hengel, A., & Brooks, M. (2006). Constrained generalised principal component analysis. In A. Ranchordas, H. Araujo, & B. Encarnacao (Eds.), Proceedings of VISAPP 2006 Vol. 1 (pp. CDROM206-CDROM212). CDROM: INSTICC.
2005 Scoleri, T., Chojnacki, W., & Brooks, M. (2005). A multi-objective parameter estimator for image mosaicing. In A. Bouzerdoum, & A. Beghdadi (Eds.), Proceedings of the 8th International Symposium on Signal Processing and its Applications Vol. 2 (pp. 551-554). USA: IEEE.
DOI Scopus11 WoS4
2003 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2003). FNS, CFNS, and HEIV: extending three vision parameter estimation methods. In C. Sun, H. Talbot, S. Ourselin, & T. Adriaansen (Eds.), Digital Image Computing: Techniques and Applications - Proceedings of the VIIth Biennial Australian Pattern Recognition Society Conference - DICTA 2003 (pp. 449-458). Victoria, Australia: CSIRO Publishing.
2003 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2003). FNS and HEIV: relating two vision parameter estimation frameworks. In M. Feretti (Ed.), Proceedings of the 12th International Conference on Image Analysis and Processing 2003 (pp. 152-157). California, USA: IEEE.
DOI Scopus2 WoS2
2003 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2003). A statistical rationalisation of Hartley's normalised eight-point algorithm. In M. Feretti (Ed.), Proceedings of the 12th International Conference on Image Analysis and Processing 2003 (pp. 334-339). California, USA: IEEE.
DOI Scopus5 WoS1
2003 Pooley, D., Brooks, M., Van Den Hengel, A., & Chojnacki, W. (2003). A voting scheme for estimating the synchrony of moving-camera videos. In L. Torres (Ed.), Proceedings of the 2003 IEEE International Conference on Image Processing Vol. 1 (pp. CDROM 1-CDROM 4). CDROM: IEEE.
DOI Scopus20 WoS11
2002 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2002). A new approach to constrained parameter estimation applicable to some computer vision problems. In D. Suter (Ed.), Proceedings of the Statistical Methods in Video Processing Workshop (pp. 43-48). Victoria, Australia: Monash University.
2002 Van Den Hengel, A., Chojnacki, W., Brooks, M., & Gawley, D. (2002). A new constrained parameter estimator: experiments in fundamental matrix computation. In P. L. Rosin, & D. Marshall (Eds.), Proceedings of the 13th British Machine Vision Conference (BMVC 2002) (pp. 468-476). UK: British Machine Vision Association.
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2001 Brooks, M., Chojnacki, W., Gawley, D., & Van Den Hengel, A. (2001). Is covariance information useful in estimating vision parameters?. In S. El-Hakim, & A. Gruen (Eds.), Proceedings of SPIE - The International Society for Optical Engineering Vol. 4309 (pp. 195-203). PO BOX 10 BELLINGHAM WASHINGTON USA: THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS.
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2001 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2001). A fast MLE-based method for estimating the fundamental matrix. In P. Pitas (Ed.), Proceedings of the International Conference on Image Processing Vol. 2 (pp. CDROM 1-CDROM 4). CD-ROM: THE INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS.
DOI Scopus2
2001 Brooks, M., Chojnacki, W., Gawley, D., & Van Den Hengel, A. (2001). What value covariance information in estimating vision parameters?. In Bob Werner (Ed.), Proceedings of the Eighth IEEE International Conference on Computer Vision Vol. 1 (pp. 302-308). LOS ALAMITOS, CALIFORNIA, USA: IEEE COMPUTER SOCIETY.
DOI Scopus49 WoS35
2001 Chojnacki, W., Brooks, M. J., Hengel, A. V. D., & Gawley, D. (2001). A fast MLE-based method for estimating the fundamental matrix.. In ICIP (2) (pp. 189-192). IEEE.
2000 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2000). Estimating vision parameters given data with covariances. In M. Mirmehdi, & B. Thomas (Eds.), Proceedings of the 11th British Machine Vision Conference 2000 (pp. 182-191). Bristol, UK: ILES Central Press.
2000 Chojnacki, W., Brooks, M., & Van Den Hengel, A. (2000). A simplified treatment of Kanatani's renormalisation method. In J. Wang (Ed.), Proceedings of ICARV 2000 - Sixth International Conference on Control, Automation, Robotics and Vision (pp. CD). Singapore: School of Electrical & Electronic Engineering, NTU.
2000 Chojnacki, W., Brooks, M., & Van Den Hengel, A. (2000). A framework for understanding renormalisation-type methods in computer vision. In J. Blanc Talon, D. Popescu, & G. Lasker (Eds.), Proceedings of Advanced Concepts for Intelligent Vision Systems ACIVS - 2000 (pp. 13-19). Ontario, Canada: The International Institute for Advanced Studies in Systems Research and Cybernetics.
2000 Chojnacki, W., Brooks, M., Van Den Hengel, A., & Gawley, D. (2000). A fast MLE-based method for estimating the fundamental matrix. In C. Sun, P. Ogunbona, W. Li, & R. Beare (Eds.), Proceedings of APRS/IEEE Workshop on Stereo Image and Video Processing (pp. 33-36). Australia: Australian Pattern Recognition Society.
1998 Brooks, M. J., Chojnacki, W., Dick, A., van den Hengel, A., Kanatani, K., & Ohta, N. (1998). Incorporating optical flow uncertainty information into a self-calibration procedure for a moving camera. In S. F. ElHakim, & A. Gruen (Eds.), Proceedings of SPIE Vol. 3641 Videometrics VI (pp. 183-192). San Jose, CA: SPIE.
DOI Scopus1
1998 Brooks, M. J., Chojnacki, W., van den Hengel, A., & Baumela, L. (1998). Robust techniques for the estimation of structure from motion in the uncalibrated case. In H. Burkhardt, & B. Neumann (Eds.), Computer Vision - ECCV'98: proceedings vol.1 Vol. 1406 (pp. 281-295). Freiburg, Germany: Springer.
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1997 Brooks, M. J., Baumela, L., & Chojnacki, W. (1997). Egomotion from optical flow with an uncalibrated camera. In J. Biemond, & E. J. Delp (Eds.), Proceedings of SPIE the International Society for Optical Engineering Vol. 3024 (pp. 220-228). SAN JOSE, CA: SPIE - INT SOC OPTICAL ENGINEERING.
DOI Scopus2 WoS2
1995 Brooks, M. J., Chojnacki, W., & van den Hengel, A. (1995). Solving the shape-from-shading problem on the CM-5. In Proceedings: CAMP '95 Conference on Computer Architectures for Machine Perception (pp. 196-201). Como, Italy: IEEE.
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1994 Brooks, M. J., & Chojnacki, W. (1994). Direct Computation of Shape from Shading. In Proceedings International Conference on Pattern Recognition Vol. 1 (pp. 114-119). JERUSALEM, ISRAEL: I E E E, COMPUTER SOC PRESS.
DOI Scopus15 WoS8

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