Abstract: A method and an image processing apparatus for image-based object feature description are provided. In the method, an object of interest in an input image is detected and a centroid and a direction angle of the object of interest are calculated. Next, a contour of the object of interest is recognized and a distance and a relative angle of each pixel on the contour to the centroid are calculated, in which the relative angle of each pixel is calibrated by using the direction angle. Then, a 360-degree range centered on the centroid is equally divided into multiple angle intervals and the pixels on the contour are separated into multiple groups according to a range covered by each angle interval. Afterwards, a maximum among the distances of the pixels in each group is obtained and used as a feature value of the group. Finally, the feature values of the groups are normalized and collected to form a feature vector that serves as a feature descriptor of the object of interest.

Abstract: A method and an image processing apparatus for image-based object feature description are provided. In the method, an object of interest in an input image is detected and a centroid and a direction angle of the object of interest are calculated. Next, a contour of the object of interest is recognized and a distance and a relative angle of each pixel on the contour to the centroid are calculated, in which the relative angle of each pixel is calibrated by using the direction angle. Then, a 360-degree range centered on the centroid is equally divided into multiple angle intervals and the pixels on the contour are separated into multiple groups according to a range covered by each angle interval. Afterwards, a maximum among the distances of the pixels in each group is obtained and used as a feature value of the group. Finally, the feature values of the groups are normalized and collected to form a feature vector that serves as a feature descriptor of the object of interest.