US 7,453,587 B2Granted

Method for removing streaks from a scanned image

AssigneeLexmark International, Inc.

InventorsWilliam Everett Gardner, Du-Yong Ng

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Abstract

A method for removing streaks from a scanned image includes performing a scanner light source OFF scan to generate a dark image having M rows of pixels and N+W columns of pixels; generating a line noise profile for the N columns of pixels of the dark image; performing a scanner light source ON scan to generate a regular image having M rows of pixels and N+W columns of pixels; processing the W columns of pixels of the regular image to detect a magnitude of the streak in the regular image; use the magnitude of the streak and the line noise profile to predict an amount of dark noise removal for each of the N columns of pixels of the regular image at the location of the streak; and subtracting the predicted amount of dark noise removal for each of the N columns of pixels from the respective N columns of pixels of the regular image.

Claims14

Dependent claims

In a scanner with a scan bar having a sensor defining N+W pixels in a row, wherein the N pixels are content pixels that are exposed to a scanner light source and the W pixels are non-content pixels that are not exposed to said scanner light source, each pixel being represented by data, a method for removing streaks from a scanned image, comprising:

performing a scanner light source OFF scan to generate a dark image having M rows of pixels and N+W columns of pixels;
generating a line noise profile for said N columns of pixels of said dark image;
performing a scanner light source ON scan to generate a regular image having M rows of pixels and N+W columns of pixels;
determining a location of a streak in said regular image;
processing said W columns of pixels of said regular image to detect a magnitude of said streak in said regular image;
using said magnitude of said streak and said line noise profile to predict an amount of dark noise removal for each of said N columns of pixels of said regular image at said location of said streak;
and
subtracting the predicted amount of dark noise removal for each of said N columns of pixels from the respective N columns of pixels of said regular image to remove said streak.

5 more elements

An imaging apparatus, comprising:

a scanner with a scan bar having a scanner light source and a sensor defining N+W pixels in a row, wherein the N pixels are content pixels that are exposed to said scanner light source and the W pixels are non-content pixels that are not exposed to said scanner light source, each pixel being represented by data;
and
a controller coupled to said scanner, said controller executing program instructions to perform a method for removing streaks from a scanned image, comprising:
performing a scanner light source OFF scan to generate a dark image having M rows of pixels and N+W columns of pixels;
generating a line noise profile for said N columns of pixels of said dark image;
performing a scanner light source ON scan to generate a regular image having M rows of pixels and N+W columns of pixels;
determining a location of a streak in said regular image;
processing said W columns of pixels of said regular image to detect a magnitude of said streak in said regular image;
using said magnitude of said streak and said line noise profile to predict an amount of dark noise removal for each of said N columns of pixels of said regular image at said location of said streak;
and
subtracting the predicted amount of dark noise removal for each of said N columns of pixels from the respective N columns of pixels of said regular image to remove said streak.

8 more elements

Dependencies are inferred from the claim text.