Double-telecentric lens calibration method based on binary quartic polynomial distortion error compensation

A bi-telecentric lens, quartic polynomial technology, applied in image data processing, instruments, calculations, etc., can solve problems such as low accuracy
CN104881874AInactive Publication Date: 2015-09-02NORTHWESTERN POLYTECHNICAL UNIV
2 Cites 17 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
NORTHWESTERN POLYTECHNICAL UNIV
Publication Date
2015-09-02
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a double-telecentric lens calibration method based on binary quartic polynomial distortion error compensation, and the method is used to solve a technical problem that an existing double-telecentric lens calibration method is low in precision. The technical scheme is that a double-telecentric lens and a CCD camera are used to set up a telecentric measuring system, a checker calibration board is adjusted to obtain clear calibration board images, a Harris algorithm is applied to obtain sub pixel angle point coordinates of a checker image; considering that a distortion center would influence the calibration precision, a u0 and a v0 are introduced when a parallel projection model of a double-telecentric lens is established; according to an existing distortion model, a binary quartic polynomial is used to perform distortion error compensation; according to characteristics of the established model, in a calibration solving process, a three-step method is used, and a calibration parameter linear resolution result is used as an initial value of a nonlinear optimization input parameter, so as to improve optimization efficiency. The method is simple in calibration process, other special experiment equipment is not needed, and calibration precision of the double-telecentric lens is improved.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a bi-telecentric lens calibration method, in particular to a bi-telecentric lens calibration method based on binary quaternary polynomial distortion error compensation. Background technique

[0002] In the field of engineering, parts with complex shape curves and surface features play a pivotal role, so it is of great significance to accurately and efficiently evaluate their shape features such as contour curves and surfaces. Traditional measurement technology has great limitations in the measurement of these parts. As an emerging measurement technology, visual measurement technology has the characteristics of fast measurement speed and high precision. It has been widely used in precision manufacturing and other fields. In recent years, with the development of optical devices, more and more bi-telecentric lenses are used for scene acquisition and detection in visual measurement. This is because the bi-telecentric lens has low...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More