US 5,899,999 A · Iterative convolution filter particularly suited for use in an image classification and retrieval system

Abstract

Apparatus and an accompanying method for an iterative convolution filter for determining an image signature and which is particularly useful in a system for automatically classifying individual images, on a numerical basis, in, e.g., an image database, and, through a query-by-example paradigm, retrieving a desired image(s) therefrom. Specifically, a signature is computed for an image using multi-level (e.g. L levels) iterative convolution filtering, with pixel values for each color axis supplied as input to each filtering level being separately convolved with each one of a set of, e.g., K predefined kernels, each being, e.g., a derivative of a Guassian kernel, to yield an output image. Each of the output images, of which K.sup.L occur for each color axis, is either applied as input to the next filtering level or applied to a summer to yield a resultant sum over all pixel values in that particular output image. This sum becomes the value of a corresponding one of K.sup.L elements, for each color axis, in the signature.

Claims33

Dependent claims

Apparatus, responsive to an input image, for generating a signature therefor and having a numeric value for each of a plurality of pre-defined characteristics present in the input image, the apparatus comprising:

at least three successive convolution filters, responsive to the input image, for producing through iterative convolution a final response image for each one of said pre-defined characteristics so as to yield a plurality of final response images, wherein each of said filters comprises:
a convolver for separately convolving pixel values for each incoming image with each one of a plurality of predefined kernels to yield a corresponding one of a plurality of convolved images, said each incoming image for a first one of said filters being the input image, and for each subsequent filter being a different corresponding filter input image related to each separate convolved image produced by an immediately preceding one of said convolution filters;
and
a sum and normalizer for separately summing all pixel values in each one of the final response images produced by a last one of the convolution filters to yield a resultant sum and for normalizing the resultant sum by a total number of pixels in the final response image produced by the last filter so as to yield a value of a different corresponding one of the pre-defined characteristics.

1 more element

Apparatus, responsive to an input image having pixel values for a plurality (C) of different color axes, for generating a signature therefor and having a numeric value for each of a plurality of pre-defined characteristics present in the input image, the apparatus comprising:

a plurality of convolution filters, responsive to the pixel values of the input image for each one of said color axes, for producing a final response image for each one of said pre-defined characteristics so as to yield a plurality of final response images, comprising:
first, second and third filters, arranged in succession, for iteratively and separately convolving the pixel values in an incoming image correspondingly applied to the first, second and third filters with each one of K individual kernels in first, second and third sets of predefined kernels, respectively, to yield a corresponding one of a plurality of convolved images, wherein said incoming image for a first one of said filters is the pixel values of the input image and for said color axis, and the incoming image for each subsequent one of the filters is a different corresponding filter input image related to each separate convolved image for said color axis and produced by an immediately preceding one of said filters;
and
a sum and normalizer for separately summing all pixel values in each one of the final response images produced by a last one of the convolution filters to yield a resultant sum and for normalizing the resultant sum by a total number of pixels in the final response image produced by the last filter so as to yield a value of a different corresponding one of the pre-defined characteristics;
whereby the signature has values for C.times.K.sup.3 different ones of said characteristics.

2 more elements

A method for generating a signature for an input image and which has a numeric value for each of a plurality of pre-defined characteristics present in the input image, the method comprising the steps of:

producing, in response to the input image and through iterative convolution using three successive convolution filters, a final response image for each one of said pre-defined characteristics so as to yield a plurality of final response images, wherein in each of said filters:
separately convolving pixel values for each incoming image with each one of a plurality of predefined kernels to yield a corresponding one of a plurality of convolved images, said each incoming image for a first one of said filters being the input image, and for each subsequent filter being a different corresponding filter input image related to each separate convolved image produced by an immediately preceding one of said convolution filters;
separately summing all pixel values in each one of the final response images produced by a last one of the convolution filters to yield a resultant sum;
and
normalizing the resultant sum by a total number of pixels in the final response image produced by the last filter so as to yield a value of a different corresponding one of the pre-defined characteristics.

2 more elements

A method for generating a signature for an input image having pixel values for a plurality (C) of different color axes, for generating a signature therefor and having a numeric value for each of a plurality of pre-defined characteristics present in the input image, the method comprising the steps of:

producing, in response to the pixel values of the input image for each one of said color axes, a final response image for each one of said pre-defined characteristics so as to yield a plurality of final response images, comprising:
iteratively and separately convolving, through successively arranged first, second and third filters, the pixel values in an incoming image correspondingly applied to the first, second and third filters with each one of K individual kernels in first, second and third sets of predefined kernels, respectively, to yield a corresponding one of a plurality of convolved images, wherein said incoming image for a first one of said filters is the pixel values of the input image and for said color axis, and the incoming image for each subsequent one of the filters is a different corresponding filter input image related to each separate convolved image for said color axis and produced by an immediately preceding one of said filters;
and
separately summing all pixel values in each one of the final response images produced by a last one of the convolution filters to yield a resultant sum;
and
normalizing the resultant sum by a total number of pixels in the final response image produced by the last filter so as to yield a value of a different corresponding one of the pre-defined characteristics;
whereby the signature has values for C.times.K.sup.3 different ones of said characteristics.

4 more elements

Dependencies are inferred from the claim text.

Iterative convolution filter particularly suited for use in an image classification and retrieval system

Life of this patent

Iterative convolution filter particularly suited for use in an image classification and retrieval system

Life of this patent

Abstract

Claims33