Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, and a non-transitory computer-readable medium.
Description of the Related Art
With the development of robot technology in recent years, complicated tasks that thus far people have performed, such as assembling an industrial product, are in the process of coming to be performed instead by robots. To perform assembling, such a robot grips a component by using an end effector such as a hand. For the robot to grip the component, there is a need to measure a relative position and orientation (hereinafter, simply referred to as position and orientation) between the component that is a target of gripping and the robot (hand). Measurement of such position and orientation can additionally be applied to various objectives, such as self-position estimation for the robot to autonomously move, or alignment between a virtual object and a physical space (a physical object) in augmented reality.
As a method of measuring the position and orientation of an object, T. Drummond and R. Cipolla, “Real-time visual tracking of complex structures”, IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 24, no. 7, pp. 932-946, 2002 discloses a method of causing a projection image of a three-dimensional model of an object represented by a collection of line segments to match an edge feature on an image obtained by an image capturing apparatus. Specifically, based on a coarse position and orientation provided as known information, a line segment in a three-dimensional model is projected onto an image. Next, edge features corresponding to each control point discretely arranged on the projected line segment are detected from the image. Then final position and orientation measurement values are obtained by correcting the coarse position and orientation so that a sum of squares of distances on the image between the projection image of the line segment to which the control points belong and corresponding edge features is a minimum.