US 7,099,510 B2 · Method and system for object detection in digital images

Abstract

An object detection system for detecting instances of an object in a digital image includes an image integrator and an object detector, which includes a classifier (classification function) and image scanner. The image integrator receives an input image and calculates an integral image representation of the input image. The image scanner scans the image in same sized subwindows. The object detector uses a cascade of homogenous classification functions or classifiers to classify the subwindows as to whether each subwindow is likely to contain an instance of the object. Each classifier evaluates one or more features of the object to determine the presence of such features in a subwindow that would indicate the likelihood of an instance of the object in the subwindow.

Claims37

Dependent claims

A method for detecting certain objects in an image, comprising the computer-implemented steps of:

placing a working window at different positions in an input image such that the input image is divided into a plurality of same dimension subwindows;
providing a cascade of homogeneous classifiers each represented by a respective homogenous classification function covering a plurality of features, each of the homogenous classification functions in sequence in the cascade respectively having increasing accuracy in identifying features associated with the certain objects such that one classifier identifies the plural features at one level of accuracy and a subsequent classifier in the cascade sequence identifies the same plural features at an increased level of accuracy with respect to the one classifier;
and
for each subwindow, employing the cascade of homogenous classification functions to quickly detect instances of the certain objects in the image in a manner enabling real-time application, said employing including discarding subwindows that insufficiently show features of the certain objects and continuing to process through the cascade only subwindows having sufficient features that indicate a likelihood of an instance of the certain objects in the subwindows.

1 more element

An object detection system for detecting certain objects in an image, comprising:

an image scanner for placing a working window at different positions in an input image such that the input image is divided into a plurality of same dimension subwindows;
and
an object detector for providing a cascade of homogeneous classifiers each represented by a respective homogenous classification function covering a same plurality of features, each of the homogenous classification functions in sequence in the cascade respectively having increasing accuracy in identifying features associated with the certain objects such that one classifier identifies the plural features at one level of accuracy and a subsequent classifier in the cascade sequence identifies the same plural features at an increased level of accuracy with respect to the one classifier;
the object detector employing, for each subwindow, the cascade of homogenous classification functions to quickly detect instances of the certain objects in the image in a manner enabling real-time application, including discarding a subwindow that insufficiently shows features of the certain objects and continuing to process through the cascade only subwindows having sufficient features that indicate a likelihood of an instance of the certain objects in the subwindows.

1 more element

A method for detecting certain objects in an image, comprising the computer-implemented steps of:

(i) dividing an input image into a plurality of subwindows, each subwindow having a sufficient size to allow processing of features associated with the certain objects;
and
(ii) processing the subwindows at an average processing rate less than about 200 arithmetic operations for each subwindow by:
(a) for each subwindow, evaluating the features in the subwindow at one level of accuracy followed by evaluating the same features at increasing levels of accuracy;
and
(b) classifying each subwindow to detect an instance of the certain objects based on the step of evaluating the features, such that instances of the certain objects are quickly detected enabling real-time application, said classifying including discarding a subwindow that insufficiently shows features of the certain objects and continuing to evaluate only subwindows having sufficient features that indicate a likelihood of an instance of the certain objects in the subwindows.

3 more elements

An object detection system for detecting certain objects in an image, comprising:

(i) an image scanner for dividing an input image into a plurality of subwindows, each subwindow having a sufficient size to allow processing of features associated with the certain objects;
and
(ii) an object detector for processing the subwindows at an average processing rate less than about 200 arithmetic operations for each subwindow by:
(a) for each subwindow, evaluating the features in the subwindow at one level of accuracy followed by evaluating the same features at increasing levels of accuracy;
and
(b) classifying each subwindow to detect an instance of the certain objects based on the step of evaluating the features, including discarding a subwindow that insufficiently shows features of the certain objects and continuing to evaluate only subwindows having sufficient features that indicate a likelihood of an instance of the certain objects in the subwindows, said image scanner and object detector providing quick detection of instances of the certain objects in a manner enabling real-time application.

3 more elements

Dependencies are inferred from the claim text.

Method and system for object detection in digital images

Life of this patent

Method and system for object detection in digital images

Life of this patent

Abstract

Claims37