sharpness

The informal, subjective evaluation of detail in the clarity or resolution seen in an image. Note: Often sharpness and resolution are assumed to be directly related, because images possessed of greater sharpness are assumed to have greater resolution. An increase in subjective sharpness is usually reported when objects are more clearly delineated from each other and from background having hard, sharply defined edges. A major contribution to subjective sharpness is this high contrast at edge transitions, as is emphasized by both edge enhancement and aperture correction, for example. In many practical systems, increasing the contrast at edge transitions is often accompanied by a reduction in fine detail, and under these conditions sharpness and resolution may describe opposite characteristics. [After SMPTE]