1. A method of accumulating an image of a specimen using a scanning-type microscope, comprising the following steps: directing a beam of radiation from a source through an illuminator so as to irradiate a surface S of the specimen; using a detector to detect a flux of radiation emanating from the specimen in response to said irradiation; causing said beam to follow a scan path relative to said surface; for each of a set of sample points in said scan path, recording an output Dn of the detector as a function of a value Pn of a selected measurement parameter P, thus compiling a measurement set M={(Dn, Pn)}, where n is a member of an integer sequence; using computer processing apparatus to automatically deconvolve the measurement set M and spatially resolve it into a result set R representing depth-resolved imagery of the specimen, wherein, considered at a given point pi within the specimen, the method comprises the following steps: in a first probing session, employing a first beam configuration B1 to irradiate the point pi with an associated first Point Spread Function F1, whereby said beam configuration is different to said measurement parameter; in at least a second probing session, employing a second beam configuration B2 to irradiate the point pi with an associated second Point Spread Function F2, whereby F2 overlaps partially with F1 in a common overlap zone Oi in which point pi is located; using an Independent Component Analysis algorithm in said computer processing apparatus to perform spatial resolution in said overlap zone Oi.