LDB特征提取算法

libLDB is a C++ library for extracting an ultrafast and distinctive binary feature LDB (Local Difference Binary) from an image patch. LDB directly computes a binary string using simple intensity and gradient difference tests on pairwise grid cells within the patch. Relying on integral images, the average intensity and gradients of each grid cell can be obtained by only 4~8 add/subtract operations, yielding an ultrafast runtime. A multiple gridding strategy is applied to capture the distinct patterns of the patch at different spatial granularities, leading to a high distinctiveness of LDB. LDB is very suitable for vision apps which require real-time performance, especially for apps running on mobile handheld devices, such as real-time mobile object recognition and tracking, markerless mobile augmented reality, mobile panorama stitching. This software is available under the GNU General Public License (GPL) v3.