关键词: 尺度不变特征变换, 特征提取, 图像匹配, 全景视觉, 定位

Abstract: Huge time are needed in feature extraction and matching with classical SIFT in image matching as well as in image retrieval，and a real-time system can not be built when mobile robot located itself with classical SIFT.A modified SIFT is proposed by changing the cycle sequence of sample pickup and setting two different modes on feature pickup.This modified SIFT can be used in omnidirectional vison images.Invariances to image translation，scaling，rotation are kept.A new real-time location system is built with modified SIFT.Examples are presented that this modified SIFT algorithm can realize the localization effectively and stably.

Key words: Scale Invariant Feature Transform（SIFT）, feature extraction, image matching, omnidirectional vision, localization