Punktspreuzfunktion

Punktspreuzfunktion is not a widely recognized term in standard technical literature. It appears to be a misspelling or regional variant of terms such as Punktspreizfunktion or Punktverteilungsfunktion, which in many fields are used to refer to what is commonly called the point spread function (PSF). The PSF describes how an imaging system responds to a point source of light, and it is a fundamental concept in optics, astronomy, microscopy, and computer vision.

The point spread function is the two‑dimensional (or three‑dimensional, in some contexts) intensity distribution in the image plane produced by a point source. Physically, it captures the diffraction, optical aberrations, sampling, and detector effects that cause a point to appear as a blurred spot rather than a single point. Mathematically, if f represents the true scene and h the PSF, the observed image g is modeled as a convolution g = f ∗ h, often with additive noise. In the Fourier domain, G = F · H, where H is the optical transfer function (OTF), and its magnitude, the MTF, describes spatial frequency response.

PSFs are measured or estimated from calibration data, such as bright stars in astronomical images or known subresolution targets in microscopy. They can vary across the field of view (anisoplanatism) and with time, requiring spatially or temporally varying models for accurate processing. Applications include deconvolution and restoration, image reconstruction, and PSF engineering for specialized imaging tasks.

See also: point spread function, optical transfer function, deconvolution, image restoration, PSF engineering.