What is point spread function in image processing

The point spread function (PSF) describes the response of a focused optical imaging system to a point source or point object. A more general term for the PSF is the system's impulse response; the PSF is the impulse response or impulse response function (IRF) of a focused optical imaging system.

1. What does the point spread function tell you?
2. What is PSF in image?
3. What is PSF in pet?
4. How do I get PSF from an image?

What does the point spread function tell you?

In fluorescence microscopy, the acquired image is always a blurred representation of the actual object under the microscope. This blurring is described by the so-called Point Spread Function (PSF). The PSF describes what a single point in the object looks like in the image.

What is PSF in image?

The ideal point spread function (PSF) is the three-dimensional diffraction pattern of light emitted from an infinitely small point source in the specimen and transmitted to the image plane through a high numerical aperture (NA) objective.

What is PSF in pet?

Point spread function (PSF) reconstruction can improve spatial resolution and signal-to-noise ratio of PET imaging. The aim of this study was to evaluate the effectiveness of ¹⁸F-FDG PET/CT with PSF reconstruction for initial staging in rectal cancer compared with conventional PET/CT and pelvic MRI.

How do I get PSF from an image?

To be sure, you can calculate it knowing the optical resolution d = lambda / 2*NA. (NA is the second number written on the objective lens, after the slash after the magnification number.) Then divide d by the pixel spacing in the image and that is the approximate PSF size.