Quaternionic Weber Local Descriptor of Color Images

This paper proposes a simple but effective framework named quaternionic Weber local descriptor (QWLD) for color image feature extraction. Integrating quaternionic representation (QR) of the color image and Weber's law (WL), QWLD possesses both their superiorities. It uses QR to handle all color channels of the image in a holistic way while preserving their relations, and applies WL to ensure that the derived descriptors are robust and discriminative. Using the QWLD framework, we further develop the quaternionic-increment-based Weber descriptor and quaternionic-distance-based Weber descriptor in terms of different perspectives. Extensive experiments on different color image recognition problems demonstrate that the proposed framework and descriptors outperform state-of-the-art local descriptors.