Final answer:
High contrast resolution in a digital image is determined by wavelength and numerical aperture, which improve the image's sharpness and clarity.
Step-by-step explanation:
The high contrast resolution in a digital image is determined by two factors: wavelength and numerical aperture. Shorter wavelengths are able to resolve smaller objects, resulting in higher resolution. Additionally, a higher numerical aperture, which measures a lens's ability to gather light, improves the resolution of the image. These factors work together to make a digital image appear sharp with clear details.