Method and apparatus for detection of target object with improved robustness
First Claim
1. An object detection apparatus for detecting a presence of a target object in prescribed target areas on a target image taken from a fixed camera position, comprising:
- camera means, located at said fixed camera position, for taking the target image, a reference image in which the target object is known to be absent, and training images taken in which the target object is known to be present;
feature calculation means for calculating features for the target image taken by the camera means, the features including at least one of a quantity expressing a difference of contributions by principal axis components and secondary axis components in a distribution of brightness of corresponding points in each target area on the target image and the reference image, and a quantity expressing a difference between a direction of a principal axis with respect to a vector (1,
1) direction in the distribution of brightness of corresponding points in each target area on the target image and the reference image;
training means for training a classifier to classify the features calculated by the feature calculation means into those corresponding to a presence of the target object and those corresponding to an absence of the target object, by applying a training process using the training images taken by the camera means;
classifier means for classifying the features calculated by the feature calculation means into a first class corresponding to a presence of the target object and a second class corresponding to an absence of the target object by using the classifier trained by the training means; and
output means for outputting a detection result indicating the presence of the target object in the prescribed target areas on the target image taken by the camera means when the features for the target image calculated by the feature calculation means are classified into the first class by the classifier means, and the absence of the target object in the prescribed target areas on the target image taken by the camera means when the features for the target image calculated by the feature calculation means are classified into the second class by the classifier means.
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Abstract
An object detection system and a state transition detection system capable of realizing the improved robustness, general applicability, and customizability. In the system, features for the target image are calculated, where the features including at least one of a quantity expressing a difference of contributions by principal axis components and secondary axis components in a distribution of brightness of corresponding points in each target area on the target image and the reference image, and a quantity expressing a difference between a direction of a principal axis with respect to a vector (1, 1) direction in the distribution of brightness of corresponding points in each target area on the target image and the reference image; and the calculated features for the target image is classified into a first class corresponding to a presence of the target object and a second class corresponding to an absence of the target by using a classifier, according to which a detection result indicating the presence or absence of the target object is outputted.
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Citations
24 Claims
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1. An object detection apparatus for detecting a presence of a target object in prescribed target areas on a target image taken from a fixed camera position, comprising:
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camera means, located at said fixed camera position, for taking the target image, a reference image in which the target object is known to be absent, and training images taken in which the target object is known to be present; feature calculation means for calculating features for the target image taken by the camera means, the features including at least one of a quantity expressing a difference of contributions by principal axis components and secondary axis components in a distribution of brightness of corresponding points in each target area on the target image and the reference image, and a quantity expressing a difference between a direction of a principal axis with respect to a vector (1,
1) direction in the distribution of brightness of corresponding points in each target area on the target image and the reference image;training means for training a classifier to classify the features calculated by the feature calculation means into those corresponding to a presence of the target object and those corresponding to an absence of the target object, by applying a training process using the training images taken by the camera means; classifier means for classifying the features calculated by the feature calculation means into a first class corresponding to a presence of the target object and a second class corresponding to an absence of the target object by using the classifier trained by the training means; and output means for outputting a detection result indicating the presence of the target object in the prescribed target areas on the target image taken by the camera means when the features for the target image calculated by the feature calculation means are classified into the first class by the classifier means, and the absence of the target object in the prescribed target areas on the target image taken by the camera means when the features for the target image calculated by the feature calculation means are classified into the second class by the classifier means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for detecting a presence of a target object in prescribed target areas on a target image taken from a fixed camera position, comprising the steps of:
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taking a reference image in which the target object is known to be absent from said fixed camera position; taking the target image from said fixed camera position; calculating features for the target image, the features including at least one of a quantity expressing a difference of contributions by principal axis components and secondary axis components in a distribution of brightness of corresponding points in each target area on the target image and the reference image, and a quantity expressing a difference between a direction of a principal axis with respect to a vector (1,
1) direction in the distribution of brightness of corresponding points in each target area on the target image and the reference image;taking training images in which the target object is known to be present from said fixed camera position; training a classifier to be used in classifying the features into those corresponding to a presence of the target object and those corresponding to an absence of the target object, by applying a training process using the training images to the classifier; classifying the features into a first class corresponding to a presence of the target object and a second class corresponding to an absence of the target object by using the classifier trained at the training step; and outputting a detection result indicating the presence of the target object in the prescribed target areas on the target image when the features for the target image calculated at the calculating step are classified into the first class at the classifying step, and the absence of the target object in the prescribed target areas on the target image when the features for the target image calculated at the calculating step are classified into the second class at the classifying step. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification