关键词: 几何矩, 尺度不变量, 低分辨率, 波动修正

Abstract: In the calculation of scale invariants of geometric moment, image scale changes will bring errors and cause the fluctuation of scale invariants because of the discrete digital image. The error expansion phenomenon is found through analyzing the anomalistic fluctuation of geometric moment scale invariants with low resolution. It is an unreasonable fluctuation enlarged from the small quantification error. A theory explains the origin of error expansion, and the formula of error calculation is given. Combined with the actual data, it is concluded that the error expansion will cause large fluctuation of geometric moment scale invariants and bring severe interference to its invariance with low resolution. Aiming at the cause of error expansion, a new definition of geometric absolute moment and its invariants is given, which will deny the error expansion efficiently. It is proven that the scale invariants of geometric absolute moment perform better compared with traditional Hu’s invariants on low resolution through comparative experiments.

Key words: geometric moment, scale invariants, low resolution, fluctuation correction