Method and apparatus for identifying defects in a substrate surface by using dithering to reconstruct under-sampled images

A surface inspection apparatus for inspecting an object by generating a plurality of images of the object and processing those images together to produce a reconstructed image having an increased pixel density, the apparatus comprising:

• an optical system having a plurality of time delay integration (TDI) sensors for producing images of the object comprised of a plurality of image pixels configured such that the images have an initial pixel density, the TDI sensors arranged to generate a plurality of images of the object in a manner such that the images are offset a sub-pixel distance from each other;
• a scanning element that enables the TDI sensors to scan the object and generate a series of successive images of the object;
• and
• image processing circuitry for processing the plurality of successive images together to produce a reconstructed image of the object having increased pixel density.