Border tracing
AssigneeString Limited
InventorJohan Øverbye
Life of this patent
Estimating the term…
Abstract
A method for scanning for borders in an image represented by pixels, the method including a first operation comprising: estimating an attribute for each of a first set of two adjacent pixel positions in the image; assessing whether a predetermined binary condition differs in respect of the two pixel positions, and if so determining that a border is present in the part of the image represented by pixels at those positions; and if a border is determined to be present in that part of the image, estimating the direction of the border as being perpendicular to a line joining the positions of the two pixels; and initiating tracing the border in that direction.
Claims18
A method for finding borders in an image represented by pixels for processing of borders found in the image, the method including a first operation comprising:
- estimating an attribute for each of a first set of two adjacent pixel positions in the image;
- storing the estimated attributes for each of the two adjacent pixel positions of the first set;
- assessing whether a predetermined binary condition differs in respect of the first set of two adjacent pixel positions, the assessing step comprising determining the predetermined binary condition by comparing a scalar attribute of each of the first set of two adjacent pixel positions against a predetermined value, and if the predetermined binary condition differs in respect of the first set of two adjacent pixel positions determining that a border is present in a part of the image represented by pixels at those positions;
- and
- if a border is determined to be present in that part of the image, estimating a direction of the border as being perpendicular to a line joining the first set of two adjacent pixel positions;
- and
- initiating tracing the border in that direction, wherein tracing the border comprises steps of:
- selecting a second set of two adjacent pixel positions, each of those pixel positions being adjacent to a respective one of the two adjacent pixel positions of the first set and offset from that pixel position of the first set in the estimated direction;
- estimating an attribute for each of the two adjacent pixel positions of the second set;
- estimating a new direction of the border in dependence on the estimated attributes of the second set of two adjacent pixel positions and the stored estimated attributes of the first set of two adjacent pixel positions;
- and subsequently further tracing the border;
- the method further comprising storing as part of a set of locations representing a location of the border in the image the location where a linear interpolation of position with respect to the scalar attributes of the two adjacent pixel positions of the first set intersects a predetermined value.
A device for finding borders in an image represented by pixels for processing of borders found in the image, the device comprising a processor configured to receive the image, the device further being configured to perform operations comprising:
- estimating an attribute for each of a first set of two adjacent pixel positions in the image;
- storing the estimated attributes for each of the two adjacent pixel positions of the first set;
- assessing whether a predetermined binary condition differs in respect of the first set of two adjacent pixel positions, the assessing step comprising determining the predetermined binary condition by comparing a scalar attribute of each of the first set of two adjacent pixel positions against a predetermined value, and if the predetermined binary condition differs in respect of the first set of two adjacent pixel positions determining that a border is present in a part of the image represented by pixels at those positions;
- and
- if a border is determined to be present in that part of the image, estimating a direction of the border as being perpendicular to a line joining the first set of two adjacent pixel positions;
- and
- initiating tracing the border in that direction, the device being configured to trace the border by:
- selecting a second set of two adjacent pixel positions, each of those pixel positions being adjacent to a respective one of the two adjacent pixel positions of the first set and offset from that pixel position of the first set in the estimated direction;
- estimating an attribute for each of the two adjacent pixel positions of the second set;
- estimating a new direction of the border in dependence on the estimated attributes of the second set of two adjacent pixel positions and the stored estimated attributes of the first set of two adjacent pixel positions;
- and subsequently further tracing the border:
- the operations further comprising storing as part of a set of locations representing a location of the border in the image the location where a linear interpolation of position with respect to the scalar attributes of the two adjacent pixel positions of the first set intersects a predetermined value.
Dependencies are inferred from the claim text.