Method and apparatus for classifying an object
View Patent ↗A method and apparatus for classifying an object in an image is disclosed. A plurality of sub-classifiers is provided. An object is classified using input from each of the plurality of sub-classifiers.
1. A method of classifying an object in an image, comprising:
providing a plurality of sub-classifiers, the plurality of sub-classifiers comprising image-based classifiers and depth based classifiers, the image-based classifiers comprising one of a contour-based classifier and an edge-based classifier, the image-based classifiers identifying elements based on at least one image, the depth-based classifiers identifying elements based on depth relative to one of a sensor and at least one reference point, the contour-based classifiers identifying elements based on properties derived from significant intensity transitions of similar quality in an image along continuous long segments or curves, the edge-based classifiers identifying elements based on properties derived from significant intensity transitions of similar quality in an image along short, straight, continuous segments; and
classifying the object using input from each of the plurality of sub-classifiers.
2. The method of claim 1 , wherein said classifying comprises combining the plurality of sub-classifiers using a Bayesian approach.
3. The method of claim 1 , wherein said classifying comprises combining the plurality of sub-classifiers using a hybrid classifier.
4. The method of claim 3 , wherein said hybrid classifier defines hypotheses; and uses a likelihood ratio to decide which hypothesis to select.
5. The method of claim 4 , wherein a classification decision is made according to:
H 0 if f k >0
H 1 otherwise
where H 0 and H 1 , are the hypotheses and f k is the likelihood ratio.
6. The method of claim 1 , wherein the depth-based classifiers comprise measuring the peakness of a pedestrian model match.
7. The method of claim 6 , wherein the peakness of a pedestrian model match is defined as the ratio of a first pedestrian 3D score and the sum of two pedestrian 3D scores that are adjacent to the first pedestrian 3D score.
8. The method of claim 1 , wherein the depth-based classifiers comprise obtaining a ratio of a pedestrian 3D model score and a car 3D model score.
9. The method of claim 1 , wherein the depth-based classifiers comprise an eccentricity test.
10. The method of claim 9 , wherein the eccentricity test measures the flatness of a target in a depth map.
11. The method of claim 1 , wherein the depth-based classifiers comprise one of a vehicle model three-dimensional block template matching score and a pedestrian model three-dimensional block template matching score.
12. An apparatus for classifying an object in an image, comprising:
means for providing a plurality of sub-classifiers, the plurality of sub-classifiers comprising image-based classifiers and depth based classifiers, the image-based classifiers comprising one of a contour-based classifier and an edge-based classifier, the image-based classifiers identifying elements based on at least one image, the depth-based classifiers identifying elements based on depth relative to one of a sensor and at least one reference point, the contour-based classifiers identifying elements based on properties derived from significant intensity transitions of similar quality in an image along continuous long segments or curves, the edge-based classifiers identifying elements based on properties derived from significant intensity transitions of similar quality in an image along short, straight, continuous segments; and
means for classifying the object using input from each of the plurality of sub-classifiers.
13. The apparatus of claim 12 , wherein said classifying comprises combining the plurality of sub-classifiers using a Bayesian approach.
14. The apparatus of claim 12 , wherein said classifying comprises combining the plurality of sub-classifiers using a hybrid classifier.
15. The apparatus of claim 14 , wherein said hybrid classifier defines hypotheses; and uses a likelihood ratio to decide which hypothesis to select.
16. The apparatus of claim 15 , wherein a classification decision is made according to:
H 0 if f k >0
H 1 otherwise
where H 0 and H 1 , are the hypotheses and f k is the likelihood ratio.
17. The apparatus of claim 12 , wherein the depth-based classifiers comprise one of a vehicle model three-dimensional block template matching score and a pedestrian model three-dimensional block template matching score.
18. The apparatus of claim 12 , wherein the depth-based classifiers comprise measuring the peakness of a pedestrian model match.
19. The apparatus of claim 18 , wherein the peakness of a pedestrian model match is defined as the ratio of a first pedestrian 3D score and the sum of two pedestrian 3D scores that are adjacent to the first pedestrian 3D score.
20. The apparatus of claim 12 , wherein the depth-based classifiers comprise obtaining a ratio of a pedestrian 3D model score and a car 3D model score.
21. The apparatus of claim 12 , wherein the depth-based classifiers comprise an eccentricity test.
22. The apparatus of claim 21 , wherein the eccentricity test measures the flatness of a target in a depth map.
23. A computer-readable medium having stored thereon a plurality of instructions, the plurality of instructions including instructions which, when executed by a processor, cause the processor to perform the steps of a method for classifying an object in an image, comprising:
providing a plurality of sub-classifiers, the plurality of sub-classifiers comprising image-based classifiers and depth based classifiers, the image-based classifiers comprising one of a contour-based classifier and an edge-based classifier, the image-based classifiers identifying elements based on at least one image, the depth-based classifiers identifying elements based on depth relative to one of a sensor and at least one reference point, the contour-based classifiers identifying elements based on properties derived from significant intensity transitions of similar quality in an image along continuous long segments or curves, the edge-based classifiers identifying elements based on properties derived from significant intensity transitions of similar quality in an image along short, straight, continuous segments; and
classifying the object using input from each of the plurality of sub-classifiers.
24. The computer-readable medium of claim 23 , wherein said classifying comprises combining the plurality of sub-classifiers using a hybrid classifier.
25. The computer-readable medium of claim 24 , wherein said hybrid classifier defines hypotheses; and uses a likelihood ratio to decide which hypothesis to select.
26. The computer-readable medium of claim 25 , wherein a classification decision is made according to:
H 0 if f k >0
H 1 otherwise
where H 0 and H 1 , are the hypotheses and f k is the likelihood ratio.
27. The computer-readable medium of claim 23 , wherein the depth-based classifiers comprise one of a vehicle model three-dimensional block template matching score and a pedestrian model three-dimensional block template matching score.
28. The computer-readable medium of claim 23 , wherein said classifying comprises combining the plurality of sub-classifiers using a Bayesian approach.
29. The computer-readable medium of claim 23 , wherein the depth-based classifiers comprise measuring the peakness of a pedestrian model match.
30. The computer-readable medium of claim 29 , wherein the peakness of a pedestrian model match is defined as the ratio of a first pedestrian 3D score and the sum of two pedestrian 3D scores that are adjacent to the first pedestrian 3D score.
31. The computer-readable medium of claim 23 , wherein the depth-based classifiers comprise obtaining a ratio of a pedestrian 3D model score and a car 3D model score.
32. The computer-readable medium of claim 23 , wherein the depth-based classifiers comprise an eccentricity test.
33. The computer-readable medium of claim 32 , wherein the eccentricity test measures the flatness of a target in a depth map.