Defective pixel correction method and system
First Claim
1. A method for correcting at least one defective pixel in an array of pixels having a first predetermined number of rows and a second predetermined number of columns comprising:
- receiving a current pixel location;
receiving a defective pixel location that does not vary from frame to frame;
wherein receiving a defective pixel location includes;
employing a table for storing a plurality of defective pixel locations;
wherein the table includes a last entry having a row value and a column value;
wherein employing a table for storing a plurality of defective pixel locations includes;
setting the row value of the last entry in the table to a value that is greater than the first predetermined number of rows; and
selling the column value of the last entry in the table to a value that is greater than the second predetermined number of columns;
when the current pixel location is not a defective pixel location, providing a received pixel value as output pixel value; and
when the current pixel location is a defective pixel location, providing a consistent replacement pixel value as the output pixel value.
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Accused Products
Abstract
A defective pixel detection and correction mechanism for use in an image sensor integrated circuit determines whether a current pixel is a defective pixel in a consistent manner from frame to frame. The defective pixel detection and correction mechanism also replaces defective pixels with stable replacement values. The defective pixel detection and correction mechanism has a defective pixel detection mechanism that employs a look-up table with defective pixel locations for providing a non-varying determination of whether a pixel is defective or non-defective. The defective pixel detection and correction mechanism also has a defective pixel correction mechanism that employs a consistent replacement choice facility to provide a previous pixel value in the same frame, on the same row, and a predetermined number of pixels from the current pixel location as a replacement value and a replacement unit (e.g., multiplexer) for replacing the defective pixel value with the replacement value.
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Citations
19 Claims
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1. A method for correcting at least one defective pixel in an array of pixels having a first predetermined number of rows and a second predetermined number of columns comprising:
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receiving a current pixel location; receiving a defective pixel location that does not vary from frame to frame; wherein receiving a defective pixel location includes; employing a table for storing a plurality of defective pixel locations;
wherein the table includes a last entry having a row value and a column value;
wherein employing a table for storing a plurality of defective pixel locations includes;setting the row value of the last entry in the table to a value that is greater than the first predetermined number of rows; and selling the column value of the last entry in the table to a value that is greater than the second predetermined number of columns; when the current pixel location is not a defective pixel location, providing a received pixel value as output pixel value; and when the current pixel location is a defective pixel location, providing a consistent replacement pixel value as the output pixel value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A circuit for correcting defective pixels in an array having a plurality of pixels comprising:
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a defective pixel detection mechanism for providing a determination of whether a pixel is defective, the defective pixel detection mechanism having a table for storing a plurality of defective pixel locations that do not vary from frame to frame;
wherein the table has a plurality of entries, each entry having a row value and a column value, the plurality of entries including a last entry;
wherein the row value of the last entry in the table is set to a value that Is greater than the first predetermined number of rows; and
the column value of the last entry in the table Is set to a value that Is greater than the second predetermined number of columns;
wherein hardware to determine if the last entry in the table has been reached is obviated; and
a defective pixel correction mechanism that replaces a current defective pixel with a consistent replacement pixel value from the same frame, on the same row, and a predetermined number of pixels from the current defective pixel;wherein the defective pixel correction mechanism and the defective pixel detection mechanism eliminate one of artifacts that stem from inconsistent detection of defective pixel from frame to frame and artifacts that stem from inconsistent replacement of defective pixels. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. An image sensor comprising:
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(a) a sensor array having a plurality of pixels arranged in rows and columns;
wherein at least one pixel is defective;(b) a row selector coupled to the sensor array for selecting a row of the sensor array; (c) a column selector coupled to the sensor array for selecting a column of the sensor array; (d) a timing controller coupled to the row selector and column selector for providing control signals thereto; (e) a defective pixel detection mechanism that employs a look-up table with defective pixel locations for providing a determination of whether a pixel is defective or non-defective;
wherein the defective pixel locations do not vary from frame to frame;
wherein the table has a plurality of entries, each entry having a row value and a column value, the plurality of entries including a last entry;
wherein the row value of the last entry in the table is set to a value that is greater than the first predetermined number of rows; and
the column value of the last entry in the table is set to a value that is greater than the second predetermined number of columns;
wherein hardware to determine If the last entry in the table has been reached is obviated; andf) a defective pixel correction mechanism coupled to the defective pixel detection mechanism that employs a consistent replacement choice facility for providing a consistent replacement pixel value in the same frame, on the same row, and a predetermined number of pixels from the current pixel location, and a replacement unit for replacing the defective pixel value with the consistent replacement pixel value.
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Specification