Rigid Registration of Segmented Volumes in Frequency Domain Using Spherical Correlation

An algorithm for the rigid registration of binary volumes is described in this paper. Binary volumes result from a segmentation of ovarian ultrasound volumes. Rigid registration is preformed in frequency domain, where the rotation and translation can be calculated separately. The calculation of rotation is done using the amplitude spectrum and with the help of sphere correlation. The method was tested on 100 synthetic ultrasonic volume pairs. Registration accuracy was estimated by a ratio ρ that compares the intersection volume of the two registered volumes to the final volume. The average ratio ρ between registered volumes was 0.50 (std 0.09) when final result of registration was used. For comparison we tested transformation, used in synthetic volumes creation. The average ratio ρ was 0.53 (std. 0.08) in that case. Key-Words: image registration, rigid registration in frequency domain, spherical correlation