1. A system capable of generating calibration information usable for wafer inspection, the system comprising: an inspection machine usable for inspecting a wafer for detecting potential defects and/or for review thereof, and capable to obtain a scanned image of an inspected wafer area; a memory configured to store data obtained by the inspection machine and informative of the scanned image, the scanned image comprising multiple scanned frames; a processor communicatively coupled to the memory, wherein the processor is configured to: select multiple targets in each of the multiple scanned frames, each given target being an image comprising a pattern which is identifiable within an environment of the given target in the scanned image, and wherein each given target is characterized by data informative of location of the given target in the scanned image; calculate, for each of the multiple scanned frames, a target-displacement for each given target out the multiple targets selected in the respective scanned frame, the calculating based on a correlation of: (i) location of the given target in the scanned image, and (ii) location of the given target as defined by design data corresponding to the scanned image, wherein, for each given target, the calculated displacement is informative of displacement of location of the given target in the scanned image relative to its location defined by the design data; determine a frame-displacement for each of the multiple scanned frames, the determining for a given scanned frame based on the target-displacements calculated for multiple targets selected in the given scanned frame; and generate: (a) calibration information corresponding to the frame-displacements determined for the multiple scanned frames, and (b) a target database that, for each given selected target, includes an image of the given target and data informative of location of the given target in the scanned image, wherein the generated calibration information and the target database are usable for wafer inspection; an input interface configured to receive scanned image data of a second wafer area other than the inspected wafer area; a processor-based correlator, configured to: (a) define search windows for the second wafer area, each of which corresponds to one of the database targets, wherein the defining of each of the search windows is based on the determined frame-displacement of the respective scanned frame in which the corresponding target is selected, the frame-displacement determined for the inspected area; and (b) calculate for the second wafer area a run-time target-displacement for each out of multiple database targets, based on a correlation of the respective target image to at least a portion of a scanned image of the corresponding search window; and a processor-based defect detection module, configured to detect defects in the second wafer area based on at least one of the run-time target-displacements.