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US 6,408,105 B1Granted
Method for detecting slope of image data utilizing hough-transform
AssigneeAdvantest Corporation
InventorKazuyuki Maruo
Life of this patent
Estimating the term…
Abstract
Image data is edge-processed and then digitized. This image data is Hough-transformed to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space, from which coordinates with multiple intersected Hough-curves are extracted and grouped. For each group, representative coordinates are selected to estimate slopes of linear components in the image data. In this way, the linear components can be recognized from the image data to estimate the slope, thereby making it possible to modify slopes of linear components in image data of a semiconductor wafer taken at an arbitrary angle or the like.
Claims24
A method of processing data comprising:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- Hough-transforming the inputted image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space;
- extracting a plurality of coordinates from the parameter plane;
- detecting relative distances between the extracted coordinates;
- grouping the extracted coordinates in the parameter plane in accordance with the detected relative distances therebetween;
- selecting representative coordinates for each group;
- and
- estimating slopes of linear components in the image data from the selected coordinates.
5 more elements
A method of processing data comprising:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- edge-processing the inputted image data to enhance values of the pixels in edge portions in the image data;
- comparing each of the values of the pixels in the edge-processed image data with a predetermined threshold to convert the edge-processed image data into binary data;
- Hough-transforming the binary image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space;
- comparing the number of mutually-intersected Hough-curves with a predetermined threshold and extracting from the generated parameter plane coordinates of the intersection of mutually-intersected Hough-curves, the number of which is greater than said threshold;
- detecting relative distances between the extracted coordinates;
- grouping the extracted coordinates in the parameter plane in accordance with the detected relative distances therebetween;
- selecting representative coordinates for each group thus generated;
- and
- estimating slopes of linear components in the image data from the selected coordinates.
7 more elements
A method of processing data comprising:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- edge-processing the inputted image data to enhance values of the pixels in edge portions in the image data;
- comparing each of the values of the pixels in the edge-processed image data with a predetermined threshold to convert the edge-processed image data into binary data;
- performing Hough-transform for each pixel represented with position coordinates (x, y) in the binary image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space with coordinates (θ, ρ) thereof in which θ represents an angle with respect to an x axis and |ρ| represents a distance from an origin point to a linear component ρ=x cos θ+y sin θ;
- comparing the number of mutually-intersected Hough-curves with a predetermined threshold and extracting from the generated parameter plane coordinates of the intersection of mutually-intersected Hough-curves, the number of which is greater than said threshold;
- adding up the number of the extracted coordinates in the parameter plane for each angle θ to generate a histogram;
- and
- specifying an angle θ with the maximum number of the extracted coordinates from the generated histogram.
5 more elements
A method of processing data comprising:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- calculating the average of values of all the pixels in the inputted image data;
- calculating a difference between the calculated average and a value of each pixel in the image data;
- comparing the calculated difference of the value with a predetermined threshold for each pixel to convert the image data into binary data;
- Hough-transforming the binary image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space;
- comparing the number of mutually-intersected Hough-curves with a predetermined threshold and extracting from the generated parameter plane coordinates of the intersection of mutually-intersected Hough-curves, the number of which is greater than said threshold;
- grouping the extracted coordinates in the parameter plane in accordance with the proximity thereof;
- selecting representative coordinates for each group thus generated;
- and
- estimating slopes of linear components in the image data from the selected coordinates.
7 more elements
A method of processing data comprising:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- calculating the average of values of all the pixels in the inputted image data;
- calculating a difference between the calculated average and a value of each pixel in the image data;
- comparing the calculated difference of the value with a predetermined threshold for each pixel to convert the image data into binary data;
- performing Hough-transform for each pixel represented with position coordinates (x, y) in the binary image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space with coordinates (θ, ρ) thereof in which θ represents an angle with respect to an x axis and |ρ| represents a distance from an origin point to a linear component ρ=x cos θ+y sin θ;
- comparing the number of mutually-intersected Hough-curves with a predetermined threshold and extracting from the generated parameter plane coordinates of the intersection of mutually-intersected Hough-curves, the number of which is greater than said threshold;
- adding up the number of the extracted coordinates in the parameter plane for each angle θ to generate a histogram;
- and
- specifying an angle θ with the maximum number of the extracted coordinates from the generated histogram.
6 more elements
A method of processing data comprising:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- calculating the average M of values t of all the pixels in the inputted image data;
- calculating a difference |t−M| between the calculated average and a value of each pixel in the image data as a weighting coefficient;
- and
- performing Hough-transform for each pixel represented with position coordinates (x, y) in the image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space with coordinates (θ, ρ) thereof in which θ represents an angle with respect to an x axis and |ρ| represents a distance from an origin point to a linear component ρ=x cos θ+y sinθ with for each mutually intersected the Hough-curves the weighting coefficient corresponding thereto added to the number of the curves thereof.
2 more elements
An information storage medium comprising a program stored therein for causing a computer to perform:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- edge-processing the inputted image data to enhance values of the pixels in edge portions in the image data;
- comparing each of the values of the pixels in the edge-processed image data with a predetermined threshold to convert the edge-processed image data into binary data;
- Hough-transforming the binary image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space;
- comparing the number of mutually-intersected Hough-curves with a predetermined threshold and extracting from the generated parameter plane coordinates of the intersection of mutually-intersected Hough-curves, the number of which is greater than said threshold;
- detecting relative distances between the extracted coordinates;
- grouping the extracted coordinates in the parameter plane in accordance with the detected relative distances therebetween;
- selecting representative coordinates for each group thus generated;
- and
- estimating slopes of linear components in the image data from the selected coordinates.
7 more elements
An information storage medium comprising a program stored therein for causing a computer to perform:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- edge-processing the inputted image data to enhance values of the pixels in edge portions in the image data;
- comparing each of the values of the pixels in the edge-processed image data with a predetermined threshold to convert the edge-processed image data into binary data;
- performing Hough-transform for each pixel represented with position coordinates (x, y) in the binary image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space with coordinates (θ, ρ) thereof in which θ represents an angle with respect to an x axis and |ρ| represents a distance from an origin point to a linear component ρ=x cos θ+y sin θ;
- comparing the number of mutually-intersected Hough-curves with a predetermined threshold and extracting from the generated parameter plane coordinates of the intersection of mutually-intersected Hough-curves, the number of which is greater than said threshold;
- adding up the number of the extracted coordinates in the parameter plane for each angle θ to generate a histogram;
- and
- specifying an angle θ with the maximum number of the extracted coordinates from the generated histogram.
5 more elements
An information storage medium comprising a program stored therein for causing a computer to perform:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- calculating the average of values of all the pixels in the inputted image data;
- calculating a difference between the calculated average and a value of each pixel in the image data;
- comparing the calculated difference of the value with a predetermined threshold for each pixel to convert the image data into binary data;
- Hough-transforming the binary image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space;
- comparing the number of mutually-intersected Hough-curves with a predetermined threshold and extracting from the generated parameter plane coordinates of the intersection of mutually-intersected Hough-curves, the number of which is greater than said threshold;
- grouping the extracted coordinates in the parameter plane in accordance with the proximity thereof;
- selecting representative coordinates for each group thus generated;
- and
- estimating slopes of linear components in the image data from the selected coordinates.
7 more elements
An information storage medium comprising a program stored therein for causing a computer to perform:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- calculating the average of values of all the pixels in the inputted image data;
- calculating a difference between the calculated average and a value of each pixel in the image data;
- comparing the calculated difference of the value with a predetermined threshold for each pixel to convert the image data into binary data;
- performing Hough-transform for each pixel represented with position coordinates (x, y) in the binary image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space with coordinates (θ, ρ) thereof in which θ represents an angle with respect to an x axis and |ρ| represents a distance from an origin point to a linear component ρ=x cos θ+y sin θ;
- comparing the number of mutually-intersected Hough-curves with a predetermined threshold and extracting from the generated parameter plane coordinates of the intersection of mutually-intersected Hough-curves, the number of which is greater than said threshold;
- adding up the number of the extracted coordinates in the parameter plane for each angle θ to generate a histogram;
- and
- specifying an angle θ with the maximum number of the extracted coordinates from the generated histogram.
6 more elements
An information storage medium comprising a program stored therein for causing a computer to perform:
- inputting image data comprising multiple pixels each having a multilevel value set in digital form;
- calculating the average M of values t of all the pixels in the inputted image data;
- calculating a difference |t−M| between the calculated average and a value of each pixel in the image data as a weighting coefficient;
- and
- performing Hough-transform for each pixel represented with position coordinates (x, y) in the image data to generate a parameter plane in which multiple Hough-curves are plotted in a parameter space with coordinates (θ, ρ) thereof in which θ represents an angle with respect to an x axis and |ρ| represents a distance from an origin point to a linear component ρ=x cos θ+y sin θ with for each mutually intersected the Hough-curves the weighting coefficient corresponding thereto added to the number of the curves thereof.
2 more elements
Dependencies are inferred from the claim text.