Final answer:
Spatial resolution in digital imaging is limited by the size of the pixels on the detector. Larger telescope apertures and image analysis software can improve quality, but not beyond the physical limits set by pixel size.
Step-by-step explanation:
The spatial resolution in digital imaging refers to the capability of the imaging system to resolve fine details in the image being captured. It is fundamentally limited by the size of the pixels on the detector. Resolution is often discussed in terms of pixels and arcseconds, where one arcsecond is 1/3600 of a degree, and it indicates the angle that an object subtends in the sky. A common comparison to understand this would be that 1 arcsecond is roughly the size of a quarter seen from 5 kilometers away. Telescopes, like the Hubble Space Telescope, are designed with large apertures to produce sharper images, surpassing the limitations caused by Earth's atmosphere.
Factors such as the size of the telescope's aperture and the wave properties of light play a significant role in determining the resolution. In the human eye, the acuity is related to how small an image can be on the retina and still be discernible. This is related not only to the physical anatomy of the eye but also to the processing performed by the brain.
Image analysis software can improve the image quality by processing the data captured by the detector. Nonetheless, the inherent resolution is ultimately constrained by the detector size. Enhancements made through software cannot overcome the physical limit imposed by pixel size.