Image processing method and apparatus

In an apparatus for generating a three-dimensional computer model of an object by processing images of the object taken from a plurality of different viewpoints to match features in the images, calculating the viewpoints at which the images were recorded using the matched features, and generating a three-dimensional computer model of the surface object using the calculated viewpoints, an improvement comprising matching features in the images by:

• storing image data;
• detecting the presence of features in the images represented by stored image data utilizing a plurality of different sized regions of the images to determine values representative of the presence of features in the image data;
• characterizing image points selected as being representative of features in the image data on the basis of the values, utilizing different sized regions of the images for the image points wherein the size of a region used to characterize an image point is selected on the basis of the size of the region utilized to determine a value representative of the presence of features in the image data for the image point, and
• matching the features utilizing the characterizations.

In an apparatus for processing data defining images of an object to generate a three-dimensional computer model of the object by matching features in the images, calculating the viewpoints at which the images were recorded using the matched features, and generating a three-dimensional computer model of the surface of the object using the calculated viewpoints, a method of performing the processing to match the features in the images comprising:

• storing image data;
• detecting the presence of features in the images represented by stored image data utilizing a plurality of different sized regions of the images to determine values representative of the presence of features in the image data;
• characterizing image points selected as being representative of features in the image data on the basis of the values, utilizing different sized regions of the images for said image points wherein the size of a region used to characterize an image point is selected on the basis of the size of the region utilized to determine a value representative of the presence of features in the image data for the image point;
• and
• matching the features utilizing the characterizations.

A method of generating characterization data characterizing features in an image comprising the steps of:

• receiving image data;
• detecting the presence of features represented by received image data by determining for image data representative of a plurality of different sized regions of the image, values representative of the presence of features in the regions;
• and
• characterizing image points selected as being representative of features in the image data on the basis of said detection by calculating characterization values for the features, wherein the characterization values are determined utilizing image data for regions of the image centered on the features, and wherein the size of a said region for generating characterization data is selected on the basis of the size of said region utilized to detect said feature.

In a method for generating a three-dimensional computer model of an object by processing images of the object taken from a plurality of different viewpoints to match features in the images, calculating the viewpoints at which the images were recorded using the matched features, and generating a three-dimensional computer model of the surface object using the calculated viewpoints, an improvement comprising matching features in the images by:

• storing image data;
• detecting the presence of features in the images represented by stored image data utilizing a plurality of different sized regions of the images to determine values representative of the presence of features in the image data;
• characterizing image points selected as being representative of features in the image data on the basis of the values, utilizing different sized regions of the images for the image points wherein the size of a region used to characterize an image point is selected on the basis of the size of the region utilized to determine a value representative of the presence of features in the image data for the image point;
• and
• matching the features utilizing the characterizations.

Apparatus for generating characterization data characterizing an image comprising:

• a data receiver for receiving image data representative of an image;
• a feature detector for detecting a plurality of features in an image represented by image data received by said data receiver;
• and
• a feature characterizer for characterizing features detected by said feature detector, said feature characterizer being arranged to characterize portions of image data representative of regions of an image including features detected by said feature detector, wherein said feature characterizer is arranged to generate characterization data for a said region of an image such that the characterization is substantially unaffected by distortions of that region causing stretch and skew,
• wherein said feature detector is arranged to detect a plurality of different sizes of features, and wherein said feature characterizer is arranged to use the size of a feature detected by said feature detector to select the size of a said region used to generate characterization data for a said feature.

Apparatus for generating characterization data characterizing an image comprising:

• a data receiver for receiving image data representative of an image;
• a feature detector for detecting a plurality of features in an image represented by image data received by said data receiver;
• and
• a feature characterizer for characterizing features detected by said feature detector, said feature characterizer being arranged to characterize portions of image data representative of regions of an image including features detected by said feature detector, wherein said feature characterizer is arranged to generate characterization data for a said region of an image such that the characterization is substantially unaffected by distortions of that region causing stretch and skew,
• wherein said feature characterizer is arranged to determine the shape of a region to be used to generate characterization data for a feature on the basis of values of image data for a region of the image including that feature so that the characterization is substantially unaffected by distortions causing stretch and skew of that region of the image.

Apparatus for generating characterization data characterizing an image comprising:

• a data receiver for receiving image data representative of an image;
• a feature detector for detecting a plurality of features in an image represented by image data received by said data receiver;
• and
• a feature characterizer for characterizing features detected by said feature detector, said feature characterizer being arranged to characterize portions of image data representative of regions of an image including features detected by said feature detector, wherein said feature characterizer is arranged to generate characterization data for a said region of an image such that the characterization is substantially unaffected by distortions of that region causing stretch and skew,
• wherein said feature characterizer comprises:
• a luminance determinator for determining the rate of change of luminance along two axes for a said region of the image;
• an image transformer for determining a transformed image utilizing the rates of change of luminance determined by said luminance detector;
• and
• a characterization generator for generating characterization data characterizing a said region of the image utilizing the transformed image.

A method for generating characterization data characterizing an image comprising the steps of:

• receiving image data representative of an image;
• detecting a plurality of features in the image;
• and
• generating characterization data, characterizing the features by generating data characterizing portions of the image data representative of regions of images including the features, wherein said generation step is such that the characterization data generated is substantially unaffected by distortions of the regions including the features causing stretch and skew,
• wherein said determination step comprises detecting a plurality of different sized features, and wherein said characterization step includes selecting the size of a region to characterize a said feature on the basis of the size of a said feature.

An apparatus for identifying features in images comprising:

• an image receiver for receiving data representative of an image;
• a feature detector for detecting the presence of features in the image represented by image data received by said image receiver, said feature detector being arranged to determine, for image data representative of a plurality of different sized regions of the image, values representative of the presence of features in the regions;
• and
• a selector for selecting image points as being representative of features in the image data on the basis of said detection by said feature detector,
• wherein said feature detector is arranged to scale the values indicative of the presence of a feature in an image to account for variation in the values arising due to the size of the region used to determine the values.

In an apparatus for generating a three-dimensional computer model of an object by processing images of the object taken from a plurality of different viewpoints to match features in the images, calculating the viewpoints at which the images were recorded using the matched features, and generating a three-dimensional computer model of the surface object using the calculated viewpoints, an improvement comprising matching features in the images by:

• storing image data;
• detecting the presence of features in the images represented by the stored data, by determining, for image data representative of a plurality of different sized regions of a given image from among the images, values representative of the presence of features in the regions, and scaling the values to account for variation in the values arising due to the size of the region used to determine the values;
• and
• selecting image points as being representative of features in the image data on the basis of the scaled values.

In an apparatus for processing data defining images of an object to generate a three-dimensional computer model of the object by matching features in the images, calculating the viewpoints at which the images were recorded using the matched features, and generating a three-dimensional computer model of the surface of the object using the calculated viewpoints, a method of performing the processing to match the features in the images comprising:

• storing image data;
• detecting the presence of features in the images represented by stored image data, comprising determining for image data representative of a plurality of different sized regions of a given image from among the images, values representative of the presence of features in the regions, and scaling the values to account for variation in the values arising due to the size of the region used to determine the values;
• and
• selecting image points as being representative of features in the image data on the basis of the scaled values.

A method for identifying features in images comprising the steps of:

• storing image data;
• detecting the presence of features in images represented by stored image data, said detection step comprising determining for image data representative of a plurality of different sized regions of a given image from among the images, values representative of the presence of features in the regions;
• and
• selecting image points as being representative of features in the image data on the basis of said detection step, wherein said detection step includes the step of scaling the values indicative of the presence of a feature in an image to account for variation in the values arising due to the size of the region used to determine the values.

In a method of generating a three-dimensional computer model of an object by processing images of the object taken from a plurality of different viewpoints to match features in the images, calculating the viewpoints at which the images were recorded using the matched features, and generating a three-dimensional computer model of the surface object using the calculated viewpoints, an improvement comprising matching features in the images by:

• storing image data;
• detecting the presence of features in the images represented by stored image data, comprising determining for image data representative of a plurality of different sized regions of a given image from among the images, values representative of the presence of features in the regions, and scaling the values to account for variation in the values arising due to the size of the region used to determine the values;
• and
• selecting image points as being representative of features in the image data on the basis of the scaled values.

An apparatus for generating characterization data characterizing features in an image comprising:

• input means for receiving data representative of an image;
• detection means for detecting the presence of features represented by image data received by said input means, said detection means being arranged to determine, for image data representative of a plurality of different sized regions of the image, values representative of the presence of features in the regions;
• and
• characterization means for characterizing image points selected as being representative of features in the image data on the basis of the detection by said detection means, by calculating characterization values for the features, wherein the characterization values are determined utilizing image data for regions of the image including the feature, and wherein said characterization means is arranged to determine the characterization values on the basis of image data for different sized regions, the size of a given region being selected on the basis of the size of a said region utilized to detect the feature by said detection means.