Generalized statistical template matching under geometric transformations
AssigneeMitsubishi Electric Corporation
InventorAlexander Sibiryakov
Life of this patent
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Abstract
A method of detecting a geometrically transformed object in an image comprises comparing a template comprising a plurality of line segments for the object with regions of an image, and determining a similarity measure that uses a statistical measure based on the sums of pixel values of line segments of the image corresponding to each of the line segments of the template. Embodiments of the invention use a discrete set of geometrically transformed versions of the template, for example using the similarity transform.
Claims24
A method for detecting an object in an image by processing signals corresponding to the image, the method comprising:
- utilizing a processor to:
- process a template of the object to derive a representation of the template comprising a plurality of line segments distributed among a plurality of regions of the object, the plurality of line segments being defined in a vertical or horizontal direction,
- remove at least one of the object regions from the representation of the template to obtain a less complex representation of the template,
- compare the less complex representation of the template with regions of an image, and
- determine a similarity measure (S(x)) based on the comparisons between the less complex representation of the template and the image regions, wherein the similarity measure is determined using a statistical measure based on sums of pixel values and sums of squared pixel values of line segments of the image corresponding to each of the line segments of the less complex representation of the template.
A method for detecting an object in an image by processing signals corresponding to the image, the method comprising:
- utilizing a processor to:
- process a template of the object to derive a representation of the template comprising a plurality of line segments distributed among a plurality of regions of the object, the plurality of line segments being defined in a vertical or horizontal direction,
- remove at least one of the object regions from the representation of the template to obtain a less complex representation of the template,
- compare the less complex representation of the template with regions of an image, and
- determine a similarity measure (S(x)) based on the comparisons between the less complex representation of the template and the regions of the image, wherein the similarity measure is determined using a statistical measure that is a function of integral lines defined by:
- I
- 1
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- a
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- where:
- I1 is an integral line representation via sum of pixel values;
- I2 is an integral line representation via sum of squared pixel values;
- f(x,y) is the image;
- and
- a is a variable coordinate of the image pixels for a line segment.
A method for detecting a geometrically transformed object in an image by processing signals corresponding to the image, the method comprising:
- utilizing a processor to:
- geometrically transform a template of the object
- derive a representation of the geometrically transformed template comprising a plurality of line segments distributed among a plurality of regions of the object, the plurality of line segments being defined in a vertical or horizontal direction,
- remove at least one of the object regions from the representation of the geometrically transformed template to obtain a less complex representation of the geometrically transformed template,
- compare the less complex representation of the geometrically transformed template with regions of the image, and
- determine a similarity measure (S(x)) based on the comparisons between the less complex representation of the geometrically transformed template and the regions of the image, wherein the similarity measure is determined using a statistical measure based the sums of pixel values and sums of squared pixel values of line segments of the image corresponding to each of the line segments of the less complex representation of the geometrically transformed template.
A method for detecting a geometrically transformed object in an image by processing signals corresponding to the image, the method comprising:
- utilizing a processor to:
- geometrically transform a template of the object
- derive a representation of the geometrically transformed template comprising a plurality of line segments distributed among a plurality of regions of the object, the plurality of line segments being defined in a vertical or horizontal direction,
- remove at least one of the object regions from the representation of the geometrically transformed template to obtain a less complex representation of the geometrically transformed template, and
- comparing the less complex representation of the geometrically transformed template with regions of the image, and
- determine a similarity measure (S(x)) based on the comparisons between the less complex representation of the geometrically transformed template and the regions of the image, wherein the similarity measure is determined using a statistical measure that is a function of integral lines defined by:
- I
- 1
-
- (
- x
- ,
- y
- )
- =
- ∑
- a
- ≤
- x
-
-
- f
-
- (
- a
- ,
- y
- )
- ;
- I
- 2
-
- (
- x
- ,
- y
- )
- =
- ∑
- a
- ≤
- x
-
-
- f
- 2
-
- (
- a
- ,
- y
- )
- where:
- I1 is an integral line representation via sum of pixel values;
- I2 is an integral line representation via sum of squared pixel values;
- f(x,y) is the image;
- and
- a is a variable coordinate of the image pixel values for a line segment, and detecting the geometrically transformed object on the basis of S(x).
Dependencies are inferred from the claim text.