Blurring is defined in ANSI T1.801.02-1996 as "A global distortion over the entire image, characterized by reduced sharpness of edges and spatial detail."

The set of images below illustrate the behavior of the lost edge energy parameter in ANSI T1.801.03-1996 for measuring the blurring impairment. The fine detail and edges in the input image (e.g., the names of the streets on the map) have been blurred in the output image. This blurring causes a loss of edge sharpness in the output image, which is readily apparent by comparing the Spatial Information (SI) of the output image with the SI of the input image. The lost edge energy parameter compares the edge energy of the input image (shown in white, bottom left) with the edge energy of the output image (shown in white, bottom right) to quantify how much edge energy has been lost.

Input	Output
SI of Input	SI of Output