  The quality of fetal ultrasound images is significantly affected by motion
blur while the imaging system requires low motion quality in order to capture
accurate data. This can be achieved with a mathematical model of motion blur in
time or frequency domain. We propose a new model of linear motion blur in both
frequency and moment domain to analyse the invariant features of blur
convolution for ultrasound images. Moreover, the model also helps to provide an
estimation of motion parameters for blur length and angle. These outcomes might
imply great potential of this invariant method in ultrasound imaging
application.
