Image recognition system and method using holistic Harr-like feature matching
A method and system for holistic Harr-like feature matching for image recognition includes extracting features from a test image where the extracted features are Harr-like features extracted from key points in the test image, matching extracted features from the test image with features from a template image, transforming the test image according to matched extracted features, and providing match results
1 . A method of image matching a test image to a template image, the method comprising:
extracting features from a test image, wherein the extracted features are Harr-like features extracted from key points in the test image;
matching extracted features from the test image with features from a template image;
transforming the test image according to matched extracted features; and
providing match results.
2 . The method of claim 1 , wherein matching extracted features from the test image with features from a template image comprises performing a holistic feature matching operation such that features are similar in terms of Harr quantities and have consistent spatial configurations.
3 . The method of claim 2 , wherein the matching extracted features from the test image with features from a template image utilizes a formula to define good match points (g), where the formula is
g
=
exp
(
-
d
σ
-
f
γ
)
where f is mean squared Harr and d is mean squared spatial differences.
4 . The method of claim 1 , wherein the template image and the test image have illumination differences.
5 . The method of claim 1 , wherein the template image and the test image have intra-class variation.
6 . The method of claim 1 , wherein the template image and the test image have scaling and varying view angles.
7 . The method of claim 1 , wherein the template image and the test image have occlusion and clutter backgrounds.
8 . The method of claim 1 , wherein the Harr-like features comprise a set of distinctive and invariant Harr-like description features.
9 . The method of claim 1 , wherein matching extracted features from the test image with features from a template image comprises selecting coherent points which are best match pairs from noisy feature points.
10 . A device having programmed instructions for image recognition between a test image and stored template images, the device comprising:
an interface configured to receive a test image;
an extractor configured to extract features from the test image, wherein the extracted features are Harr-like features extracted from key points in the test image; and
instructions that perform a matching operation where extracted features from the test image are matched with features from a template image to generate match results.
11 . The device of claim 10 , wherein the matching operation compares Harr quantities and spatial configurations of the features.
12 . The device of claim 10 , wherein the matching operation utilizes a formula to define good match points (g), where the formula is
g
=
exp
(
-
d
σ
-
f
γ
)
where f is mean squared Harr and d is mean squared spatial differences.
13 . The device of claim 10 , wherein the template image and the test image have illumination differences.
14 . The device of claim 10 , wherein the template image and the test image have intra-class variation.
15 . The device of claim 10 , wherein the matching operation selects coherent points which are best match pairs.
16 . The device of claim 15 , wherein the best match pairs are from noisy feature points.
17 . The device of claim 10 , wherein the device is selected from the group consisting of a mobile device, a robot and a computing device.
18 . A system for image recognition, the system comprising:
a pre-processing component that performs image normalization on a test image;
a feature extraction component that extracts Harr-like features from the test image, wherein the Harr-like features are from key points in the test image;
a matching component that matches features extracted from the test image with features from a template image; and
an image transformation component that performs transformation operations on the test image.
19 . The system of claim 18 , wherein the matching component tests features based on Harr quantities and spatial configurations.
20 . The system of claim 18 , wherein the matching component selects coherent points from the test image and the template image which are best match pairs.
21 . The system of claim 20 , wherein the best match pairs are from noisy feature points.
22 . The system of claim 18 , wherein the transformation operations performed by the image transformation component comprises any one of cropping, scaling, rotation, and non-linear deformation.
23 . The system of claim 18 , further comprising a feature processing component that selects and merges feature data from the test image.
24 . A software program, embodied in a computer-readable medium, for image matching a test image to a template image, comprising:
code for extracting features from a test image, wherein the extracted features are Harr-like features extracted from key points in the test image;
code for matching extracted features from the test image with features from a template image;
code for transforming the test image according to matched extracted features; and
code for providing match results.
25 . The software program of claim 24 , wherein the code for matching extracted features from the test image with features from a template image comprises code for performing a holistic feature matching operation such that features are similar in terms of Harr quantities and have consistent spatial configurations.
26 . A system for image matching a test image to a template image, the method comprising:
means for performing image normalization on a test image;
means for extracting Harr-like features from the test image, wherein the Harr-like features are from key points in the test image;
means for matching features extracted from the test image with features from a template image; and
means for performing transformation operations on the test image.
27 . The system of claim 26 , wherein the matching means tests features based on Harr quantities and spatial configurations.