NOISE ELIMINATING METHOD, IMAGE PROCESSOR, AND INFORMATION CODE READER

摘要

PROBLEM TO BE SOLVED: To provide: a noise eliminating method capable of surely extracting and eliminating not only impulsive noise in an image in a flat region but also impulsive noise adjacent to an edge; an image processor; and an information code reader.

SOLUTION: This image processor 230 includes: a function selecting a noticed image; a first dispersion calculation function sequentially calculating dispersion values excluding the noticed pixel by at least either of variance and standard deviation for a plurality of peripheral pixel groups different in regions around the noticed pixel; a minimum value detection function detecting the minimum value within the dispersion values of the plurality of peripheral pixel groups; a second dispersion calculation function calculating a dispersion value including the noticed pixel of the peripheral pixel group from which the minimum value is obtained when the minimum value is not larger than a predetermined value; and a determination function for determining that noise of the noticed pixel is present when the difference between the minimum value and the dispersion value including the noticed pixel is large.

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