- Email: [email protected]
Derivation of optical flow using a spatiotemporal-frequency approach
130
ABSTRACTS
OF PAPERS ACCEPTED
FOR PUBLICATION
Derivatiem of Optid Fikw Using a Spatiotempod-Frulucncy Apprwcli. LOWELL JACONON AND HARRY WECHSLER. Department of Electrical Engineering, University of Minnesota, Minneapolis, Minnesota 55455. Received May I, 1986. We advance in this paper the spatiotemporal-frequency (STF) approach for computing the optical flow of a time-varying image. STF flow derivation provides an attractive alternative to earlier approaches based on (1) feature correspondence, (2) spatiotemporal gradients, and (3) Fourier-phase changes. After briefly surveying these three earlier approaches to flow computation, we provide an historical overview of the development of the STF approach. Then an improved STF method for flow derivation that has recently been developed by the authors is presented along with experimental results that demonstrate its use. We conclude by showing that STF derivation (a) promises substantially improved performance over other flow computation methods, and (b) provides a partial explanation of motion coherence as observed in human vision. A Simple Approach to the P&&m of 30 Reconstruction. L. BREVDO,~. SIDEMAN,ANDR.BEYAR. The Julius Silver Institute, Department of Bio-Medical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel. Received July 18, 1985; revised March 26, 1986. A relatively simple mathematical procedure for the reconstruction of the 3dimensional (3D) image of the left ventricle (LV) of the heart is presented. The method is based on the assumption that every ray which emanates from the midpoint of the long axis of the 3D body crosses the surface boundary of the ventricle at one and only one point. The coordinates ‘;, Qi, 6, of the data points on, say, the outer boundary, (i.e., the epicardium) are calculated in a spherical coordinate system having its origin in the midpoint of the long axis. The problem of defining the coordinates of a prescribed grid point on the boundary is treated as an interpolation problem for the function r = r(+, 0) defined in the rectangle 0 5 0 I 211; 0 5 0 I n with ‘; given in the points ($I,, 0,).
ABSTRACTS
OF PAPERS ACCEPTED
FOR PUBLICATION
Derivatiem of Optid Fikw Using a Spatiotempod-Frulucncy Apprwcli. LOWELL JACONON AND HARRY WECHSLER. Department of Electrical Engineering, University of Minnesota, Minneapolis, Minnesota 55455. Received May I, 1986. We advance in this paper the spatiotemporal-frequency (STF) approach for computing the optical flow of a time-varying image. STF flow derivation provides an attractive alternative to earlier approaches based on (1) feature correspondence, (2) spatiotemporal gradients, and (3) Fourier-phase changes. After briefly surveying these three earlier approaches to flow computation, we provide an historical overview of the development of the STF approach. Then an improved STF method for flow derivation that has recently been developed by the authors is presented along with experimental results that demonstrate its use. We conclude by showing that STF derivation (a) promises substantially improved performance over other flow computation methods, and (b) provides a partial explanation of motion coherence as observed in human vision. A Simple Approach to the P&&m of 30 Reconstruction. L. BREVDO,~. SIDEMAN,ANDR.BEYAR. The Julius Silver Institute, Department of Bio-Medical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel. Received July 18, 1985; revised March 26, 1986. A relatively simple mathematical procedure for the reconstruction of the 3dimensional (3D) image of the left ventricle (LV) of the heart is presented. The method is based on the assumption that every ray which emanates from the midpoint of the long axis of the 3D body crosses the surface boundary of the ventricle at one and only one point. The coordinates ‘;, Qi, 6, of the data points on, say, the outer boundary, (i.e., the epicardium) are calculated in a spherical coordinate system having its origin in the midpoint of the long axis. The problem of defining the coordinates of a prescribed grid point on the boundary is treated as an interpolation problem for the function r = r(+, 0) defined in the rectangle 0 5 0 I 211; 0 5 0 I n with ‘; given in the points ($I,, 0,).