0390215 20240103202314.720130312235959.9 10.2316/P.2013.798-018 8 s. C cav_un_epca*0390669978-0-88986-944-8305-312IndbruckACTA Press2013LinsenL.KampelM. image recognition Fourier transform projection operators invariants cav_un_auth*0101087 Flusser Jan Zpracování obrazové informace Department of Image Processing ZOI ZOI UTIA-B Department of Image Processing Ústav teorie informace a automatizace AV ČR, v. v. i. cav_un_auth*0101203 Suk Tomáš Zpracování obrazové informace Department of Image Processing ZOI ZOI UTIA-B Department of Image Processing Ústav teorie informace a automatizace AV ČR, v. v. i. cav_un_auth*0101071 Boldyš Jiří Zpracování obrazové informace Department of Image Processing ZOI ZOI UTIA-B Department of Image Processing Ústav teorie informace a automatizace AV ČR, v. v. i. cav_un_auth*0101238 Zitová Barbara Zpracování obrazové informace Department of Image Processing ZOI ZOI UTIA-B Department of Image Processing Ústav teorie informace a automatizace AV ČR, v. v. i. GAP103/11/1552 GA ČR cav_un_auth*0273618 In this paper, we introduce a new theory of blur invariants. Blur invariants are image features which preserve their values if the image is convolved with a point-spread function (PSF) of a certain class. We present the invariants to convolution with an arbitrary N-fold symmetric PSF, defined in Fourier domain by means of projection operators. We introduce a notion of a primordial image as a canonical form of all blur-equivalent images. We illustrate by experiments the invariance and recognition power of the new features. Potential applications of this method are wherever one wants to recognize blurred images. cav_un_auth*0290072 Signal Processing, Pattern Recognition and Applications (SPPRA 2013) Insbruck 12.02.2013-14.02.2013 AT 2013 JD 4 PR http://hdl.handle.net/11104/0219536 2013 cav_un_epca*0390669 Signal Processing, Pattern Recognition and Applications 978-0-88986-944-8 305 312 Indbruck ACTA Press 2013 Computer Graphics and Imaging 798 Linsen L. 340 Kampel M. 340