Method and apparatus for determining a defocus value and method and apparatus for image-based determination of a dimensional size

摘要

Method for determining a defocusing value (Δz, Δz ₁ , Δz ₂ ) for at least one image feature in an image, wherein at least one monochromatic image of an object (2) is generated, characterized in that at least one property of the image feature in the monochromatic image is determined, the property being a dimension of the image feature or an image position of the image feature in the image, wherein the defocusing value (Δz, Δz ₁ , Δz ₂ ) is determined depending on the characteristic of the image feature and the wavelength (λ) of the monochromatic image.