"Signal Processing, Pattern Recognition and Applications" . "Blur Invariants and Projection Operators"@en . "Blur Invariants and Projection Operators"@en . . . . "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." . "Zitov\u00E1, Barbara" . "Blur Invariants and Projection Operators" . "Blur Invariants and Projection Operators" . . . . "[586CDA2DF9C2]" . . "Flusser, Jan" . "RIV/67985556:_____/13:00390215!RIV13-GA0-67985556" . . "RIV/67985556:_____/13:00390215" . . . "P(GAP103/11/1552)" . . . "2013-02-12+01:00"^^ . "Insbruck" . "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."@en . "Suk, Tom\u00E1\u0161" . "978-0-88986-944-8" . "10.2316/P.2013.798-018" . . . "image recognition; Fourier transform; projection operators; invariants"@en . "4"^^ . . . "4"^^ . . "63659" . "ACTA Press" . . "Indbruck" . . . "Boldy\u0161, Ji\u0159\u00ED" . "8"^^ . .