Method and apparatus for extracting feature from input image

1. A method of extracting a plurality of features from an input image, the method comprising:

detecting a face area from an input image;

detecting landmarks from the face area of the input image;

detecting angles between the landmarks from the input image;

estimating a pose of a user based on the angles between the landmarks;

determining a target area of the input image from which the plurality of features are to be extracted based on the angles and the pose;

determining one of a first order of extracting the plurality of features from the target area and a second order of extracting the plurality of features from the target area based on the angles and the pose, the first order and the second order having opposite directions of extraction with respect to each other; and

extracting the plurality of features in accordance with the first order when the angles are within a preset range or extracting the plurality of features in accordance with the second order when the angles are out of the preset range.

2. The method of claim 1 , wherein the angles include an angle between a first landmark and each of landmarks other than the first landmark, the first landmark being determined first among the landmarks.

3. The method of claim 2 , wherein the input image is a facial image and the first landmark is in a central portion of a nose in the facial image.

4. The method of claim 1 , wherein the detecting the angles comprises:

calculating a first angle between a first landmark and at least one second landmark among the landmarks and a second angle between the first landmark and at least one third landmark among the landmarks.

5. The method of claim 4 , wherein the determining comprises:

determining whether each of the first angle and the second angle is within a set range; and

determining a feature extraction scheme based on whether each of the first angle and the second angle is within the set range.

6. A method of extracting a plurality of features from an input image, the method comprising:

detecting a face area from the input image;

detecting landmarks from the face area of the input image;

detecting physical characteristics between the landmarks, the detecting the physical characteristics including,

calculating a first angle between a first landmark and at least one second landmark among the landmarks and a second angle between the first landmark and at least one third landmark among the landmarks;

determining a target area of the input image from which the plurality of features are to be extracted and an order of extracting the plurality of features from the target area based on the physical characteristics, the determining including,

determining whether each of the first angle and the second angle is within a set range, and

determining a feature extraction scheme based on whether each of the first angle and the second angle is within the set range; and

extracting the plurality of features based on the order, the determining the feature extraction scheme including,

determining one of a first scheme and a second scheme as the feature extraction scheme for each of locations of the first landmark through the third landmark based on whether each of the first angle and the second angle is within the set range, the first scheme being used to extract the plurality of features from a first area of the input image in a first order, the second scheme being used to extract the plurality of features from a second area corresponding to the first area in a second order, and the first area includes the locations of the first landmark through the third landmark.

7. The method of claim 6 , wherein the determining the feature extraction scheme comprises:

extracting the plurality of features from a plurality of cells included in the first area based on the first scheme if each of the first angle and the second angle is determined to be within the set range.

8. The method of claim 6 , wherein the determining the feature extraction scheme comprises:

extracting the plurality of features from a plurality of cells included in the second area based on the second scheme it each of the first angle and the second angle is determined to be beyond the set range.