Johnston A, McOwan P W, Buxton H
Department of Psychology, University College London, U.K.
Proc Biol Sci. 1992 Dec 22;250(1329):297-306. doi: 10.1098/rspb.1992.0162.
Although spatio-temporal gradient schemes are widely used in the computation of image motion, algorithms are ill conditioned for particular classes of input. This paper addresses this problem. Motion is computed as the space-time direction in which the difference in image illuminance from the local mean is conserved. This method can reliably detect motion in first-order and some second-order motion stimuli. Components of the model can be identified with directionally asymmetric and directionally selective simple cells. A stage in which we compute spatial and temporal derivatives of the difference between image illuminance and the local mean illuminance using a truncated Taylor series gives rise to a phase-invariant output reminiscent of the response of complex cells.
虽然时空梯度算法在图像运动计算中被广泛使用，但对于特定类型的输入，算法的条件并不理想。本文旨在解决这个问题。运动被计算为图像照度与局部均值的差异保持守恒的时空方向。该方法能够可靠地检测一阶和一些二阶运动刺激。模型的组成部分可以与方向不对称和方向选择性简单细胞相识别。我们使用截断泰勒级数计算图像照度与局部平均照度之差的空间和时间导数的阶段，会产生一个类似于复杂细胞响应的相位不变输出。
