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.

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.

Abstract: A method for identifying a color block area in an image, the method comprising: a) scanning for border crossings in the image in a direction from a user-provided origin point; b) on finding a border crossing, tracing a path of the border such that the color block area is on a predetermined side of the traced path; and c) if the path encloses the origin point and is traced clockwise or counterclockwise according to the predetermined choice of keeping the color block area to the right or left respectively, determining that the border is the perimeter for the color block area; or if not, continuing to scan for border crossings in said direction.

Abstract: A method for identifying features in an image, the method comprising: a) from a first location, scanning the image along a scan path in a scan direction away from the first location so as to detect a border in the image at a second location; b) mapping a path defined by the border in a first direction along the border from the second location, the path being mapped in dependence on a border quality measure; c) determining whether the mapped path forms a perimeter; and d) if the mapped path does form a perimeter, scanning the image from the mapped path so as to detect a further border in the image; or if the mapped path does not form a perimeter, mapping a path defined by the border from the second location in a second direction along the border that is different to the first direction.

Abstract: A method for assessing the presence of a border in an image, the method comprising: for each of two pixel positions estimating the strength of the second-order rate of change of a convolution of said image at the pixel position with respect to a plurality of directions and determining a binary condition of the pixel position in dependence on whether the strength exceeds a predetermined threshold; and assessing the presence of a border by comparing the two binary conditions.

Abstract: A method for analyzing an image composed of pixels by estimating a continuous function of a selected pixel attribute, the continuous function being centered on a selected pixel position, the method comprising: determining a series of nested sets of pixels, each set being centered on a common pixel; estimating a discrete weighting for each set of pixels in accordance with the continuous function; mapping the sets of pixels onto pixels of the image with the common pixel mapped on to the selected pixel position; for each set of pixels, forming a combined value in dependence on the values of the selected pixel attribute for the pixels of the set in the image; and estimating the function as a sum of the combined values for each set weighted by the respective discrete weighting.