Perceptual thresholding for gradient-based local edge detection
First Claim
Patent Images
1. A method comprising:
- defining a localization region of an image, said localization region including a selected portion of said image; and
determining automatically, without user intervention, a threshold applied for edge detection within said localization region based on intensity information of pixels within said localization region, said threshold determined by a power function operator reflective of perceptual characteristics as it relates to intensity of a human vision system, said power function operator is a measure of relative localization intensity raised to a power factor;
wherein said relative localization intensity is a quotient of a difference between a mean and a minimum of all intensity values within said localization region and a difference between a maximum and said minimum of all intensity values within said localization region.
1 Assignment
0 Petitions
Accused Products
Abstract
What is disclosed is a method for dynamically and automatically determining the threshold value for edge detection based on localized intensity information. Each pixel can be assigned a threshold to which its gradient or other intensity change information can be compared so as to detect whether or not the pixel belongs to an edge feature of the image or not. Further, the thresholding can be based upon the response of the human vision system so that visual appearance of the image to users is considered when analyzing localized intensity information. The localized thresholding technique can be applied to any edge detection scheme.
189 Citations
22 Claims
-
1. A method comprising:
-
defining a localization region of an image, said localization region including a selected portion of said image; and determining automatically, without user intervention, a threshold applied for edge detection within said localization region based on intensity information of pixels within said localization region, said threshold determined by a power function operator reflective of perceptual characteristics as it relates to intensity of a human vision system, said power function operator is a measure of relative localization intensity raised to a power factor;
wherein said relative localization intensity is a quotient of a difference between a mean and a minimum of all intensity values within said localization region and a difference between a maximum and said minimum of all intensity values within said localization region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. An article comprising a computer readable medium including instructions stored thereon that when executed by a processor, cause:
-
defining a localization region of an image, said localization region including a selected portion of said image; and determining automatically, without user intervention, a threshold applied for edge detection within said localization region based on intensity information of pixels within said localization region, said threshold determined by a power function operator reflective of perceptual characteristics as it relates to intensity of a human vision system, said power function operator is a measure of relative localization intensity raised to a power factor;
wherein said relative localization intensity is a quotient of a difference between a mean and a minimum of all intensity values within said localization region and a difference between a maximum and said minimum of all intensity values within said localization region. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
-
Specification