正常肺功能阈值（NLT）和外推的双倍致死量（DLT）：用于扩大校准体积的三维摄影替代方法。

NLT and extrapolated DLT:3-D cinematography alternatives for enlarging the volume of calibration.

作者信息

Hinrichs R N, McLean S P

机构信息

Exercise and Sport Research Institute, Arizona State University, Tempe 85287-0404, USA.

出版信息

J Biomech. 1995 Oct;28(10):1219-23. doi: 10.1016/0021-9290(95)00034-f.

DOI:10.1016/0021-9290(95)00034-f

PMID:8550640

Abstract

This study investigated the accuracy of the direct linear transformation (DLT) and non-linear transformation (NLT) methods of 3-D cinematography/videography. A comparison of standard DLT, extrapolated DLT, and NLT calibrations showed the standard (non-extrapolated) DLT to be the most accurate, especially when a large number of control points (40-60) were used. The NLT was more accurate than the extrapolated DLT when the level of extrapolation exceeded 100%. The results indicated that when possible one should use the DLT with a control object, sufficiently large as to encompass the entire activity being studied. However, in situations where the activity volume exceeds the size of one's DLT control object, the NLT method should be considered.

摘要

本研究调查了三维摄影/摄像的直接线性变换（DLT）和非线性变换（NLT）方法的准确性。对标准DLT、外推DLT和NLT校准的比较表明，标准（非外推）DLT最为准确，尤其是在使用大量控制点（40 - 60个）时。当外推水平超过100%时，NLT比外推DLT更准确。结果表明，在可能的情况下，应使用带有控制对象的DLT，该控制对象应足够大，以涵盖所研究的整个活动。然而，在活动体积超过DLT控制对象大小的情况下，应考虑使用NLT方法。