Grasp Detection under Occlusions Using SIFT Features

Algorithm 1

Improved RANSAC algorithm.

	Input: Input parameters set of SIFT matches F
	Output: Output transformation matrix
(1)	Preprocessing: eliminate part of the mismatches by deleting the feature point pair that causes cross line. Denote the matching point set after preprocessing as .
(2)	Select 4 pairs of points from randomly, and calculate transformation matrix , create a new point set .
(3)	Judge whether other matching pairs satisfy the transformation of (a matching pair belongs to if the error less than a given threshold), record the number of satisfied matching pair (elements in ) as .
(4)	If current is the biggest than before, retain the current ; otherwise, abandon it.
(5)	Repeat 2, 3, and 4 a given times (5 in this paper), and obtain a transformation matrix .