1. A method for iterative derivation of a master image from a plurality of sampled images of non-identical, at least partially overlapping, regions of a scene, the master image having an output resolution greater than a maximum resolution of the sampled images, the method comprising: (a) for each sampled image, defining: (i) a transformation operator F mapping positions within the master image to corresponding positions in the sampled image, (ii) a distortion operator H simulating a modulation transfer function associated with an imaging sensor from which the sampled image was generated, and (iii) a sampling operator D for reducing an image from the output resolution to the resolution of the sampled image; (b) for each sampled image, applying said transformation operator, said distortion operator and said sampling operator to a current master image hypothesis so as to generate a predicted image, and calculating a difference image having pixel values corresponding to the difference in corresponding pixel values between the sampled image and the predicted image; (c) performing back-projection of each of said difference images to generate a correction image for the current master image hypothesis; and (d) employing said correction images to perform a correction to the current master image hypothesis to generate a new master image hypothesis, wherein said correction to the current master image hypothesis includes combining the correction images by deriving a weighted average of values of corresponding pixels in said correction images, the weight of each pixel in each correction image being calculated as a function of a distance as measured in the sampled image between: (i) a point in the sampled image to which the pixel in the correction image is mapped by the transformation operator; and (ii) at least one pixel centroid proximal to said point.