A medical imaging device comprising: an optical imaging module which generates an image of a region of a body part by acquiring image samples at respective sample locations in the region and mapping the samples to corresponding image pixels； a control module which controls the optical imaging module to acquire a first sequence of samples whose corresponding pixel locations follow a path which is spanned by pixels corresponding to the first sequence of samples and extends over a greater portion of the image than an arrangement in an array of a sequence of pixels corresponding to a second sequence of samples that the optical imaging module is operable to acquire, wherein a sum of distances between adjacent pixels in the sequence of pixels is equal to a length of the path； and a registration module which registers the image against a reference image.
