비선형 공간에서 고속 선명도 확산 방법을 이용한 색상불변 특성 검출

초록

In recent years, there have been significant research on robust feature extraction methods. Most state-of-the-art methods operate on grayscale images to decrease the computational expenses. We observe that this conversion can cause information loss and effect the matching performance. In this study, a multi-scale 2D invariant color detector and descriptor in nonlinear scale spaces is proposed. The algorithm exploits color information in HLS (Hue, Lightness, and Saturation) space. Nonlinear scale spaces are built separately for each color channel and adaptive Hessian responses are calculated for keypoint extraction. Fast Explicit Diffusion (FED) scheme is used for locally adaptive blurring to the image data. FED reduces image noise while preserving important edges. This aids in superior keypoint localization accuracy and feature distinctiveness. In addition, a Color Modified-Local Difference Binary (CM-LMB) descriptor is proposed. It combines HLS color information with gradient information in nonlinear scale space. Our proposed system (HLS-AKAZE) shows comparable performance in standard image datasets and good performance improvements in certain images (Less-Informative Grayscale Images). HLS-AKAZE is rotation, scale, and illumination invariant.

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