Method for reducing row noise from images
AssigneeIntel Corporation
InventorsWilliam Macy, Ajaya Durg
Life of this patent
Estimating the term…
Abstract
A method for reducing row noise from a complementary metal oxide semiconductor (CMOS) image sensor is disclosed. The method includes determining a set of row sums for a set of pixel rows in the image sensor and a set of corresponding contributing pixel counts. Then, determining a set of row offset corrections. Finally, adjusting the set of pixel rows by the set of row offset corrections.
Claims21
A method comprising:
- determining a set of row sums for a set of pixel rows and a set of corresponding contributing pixel counts, by determining if a threshold test has been passed for each pixel in a row and adding a pixel value for each pixel in the row to a row sum for the row if the threshold test has been passed and increasing a contributing pixel count for the row;
- determining a set of row offset corrections by determining if the contributing pixel count for a row passes a second threshold test and generating a row offset correction for the row, as a function of the row sum for that row, if the second threshold test has been passed and,
- adjusting the set of pixel rows by the set of row offset corrections.
An article comprising a computer readable medium having instructions stored thereon, which when executed, causes:
- determining a set of row sums for a set of pixel rows and a set of corresponding contributing pixel counts, by determining if a threshold lest has been passed for each pixel in a row and adding a pixel value for each pixel in the row to a row sum for the row if the threshold test has been passed;
- determining a set of row offset corrections;
- and,
- adjusting the set of pixel rows by the set of row offset corrections, wherein
- evaluation of the threshold test includes the following criteria
- |X[i−1,k]i−X[i+1,k]|</(X[i−1,k|+X|+1,k])<threshold value,
- where i is a coordinate identifying a row position, k is a coordinate identifying a column position of a current pixel and X[i,k] is a pixel value for the current pixel.
An article of manufacture comprising;
- a machine-accessible medium having data stored thereon which, when accessed by a processor of a personal computer system, processes an image that has been captured by a digital camera and that has been transferred to the computer system, wherein the image is processed to correct for row noise, caused by random offsets, by determining whether a value, related to a difference between a pixel above a target row and a pixel below the target row and in the same column, is less than a threshold amount and if so then adding a value of a pixel that is in the same column and that is in the target row to a row sum variable for the target row and updating a count of contributing pixels for the target row, and if the count has reached a threshold amount then computing a correction value based on an average of row sum values for non-target rows and based on the target row's row sum value.
An article comprising a computer readable medium having instructions stored thereon, which when executed, determines a row sum for a pixel row of an image and a corresponding contributing pixel count, by determining if a threshold test has been passed for each pixel of the row and adding a pixel value to the row sum if the test has been passed, determines a row offset correction, and adjusts the pixel row using the correction, wherein the evaluation of the threshold test includes determining whether:
- |[i−1,k]−X[i+1,k]|< threshold value,
- where i is a coordinate identifying a row position, k is a coordinate identifying a column position of a current pixel and X[i,k] is the pixel value for the pixel.
Dependencies are inferred from the claim text.