Selective Noise-Reducing Filter in the IBM/7350
Original Publication Date: 1985-Aug-01
Included in the Prior Art Database: 2005-Feb-19
The implementation inside the IBM/7350 of a spatial dependent filter is described. The filter in object gives the possibility to reduce noise in an 8-bit per pixel image without blurring edges. Every pixel of a given image is replaced by the average of itself and its eight neighbors, except those whose values have a difference from the selected one, greater, in absolute value, than a fixed threshold value. For example, near a boundary whose contrast is greater than the fixed threshold value, the filter allows a smoothing of the pixels on either side of the boundary, without any damage to the boundary itself.