Abstract: A method for interpolating digital images is provided. An original digital image in the spatial domain is transformed into a frequency domain representation via a Fourier transform. The Fourier transform or frequency domain representation is then modified by phase shift terms corresponding to image shifts in the spatial domain with sub-unity distances matching the locations where the image values need to be restored. The original and the shifted images are then interspersed together, yielding an interpolated image. The method is particularly useful for two and three-dimensional computer tomography (CT) and magnetic resonance imaging (MRI) images, as well as other medical and non-medical digital images.

Abstract: A method of imaging a characteristic of image intensity of an imaging agent in a subject consists of introducing the imaging agent into the subject and repetitively scanning the subject at each of a plurality of time intervals, so as to produce a plurality of time-sequenced images throughout the subject. Each of the time-sequenced images is then subdivided into a notional array of image elements such that there is a one-to-one correspondence between positions of image elements in the array and locations in the subject. Thereafter, a value of image intensity of the imaging agent at the corresponding location in the subject is determined for each image element in each of the time-sequenced images, the image elements in the arrays of successive time-sequenced images being in register with each other with respect to the locations.