scholarly journals Learning-based active 3D measurement technique using light field created by video projectors

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuki Shiba ◽  
Satoshi Ono ◽  
Ryo Furukawa ◽  
Shinsaku Hiura ◽  
Hiroshi Kawasaki
Keyword(s):  
Measurement Technique ◽  
Light Field ◽  
3D Measurement

Light field 3D measurement using unfocused plenoptic cameras

2018 ◽  
Vol 43 (15) ◽  
pp. 3746 ◽  
Author(s):  
Zewei Cai ◽  
Xiaoli Liu ◽  
Qijian Tang ◽  
Xiang Peng ◽  
Bruce Zhi Gao
Keyword(s):  
Light Field ◽  
3D Measurement

scholarly journals A real 3D measurement technique for the tibial slope: differentiation between different articular surfaces and comparison to radiographic slope measurement

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Armando Hoch ◽  
Lukas Jud ◽  
Tabitha Roth ◽  
Lazaros Vlachopoulos ◽  
Philipp Fürnstahl ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Measurement Technique ◽  
Three Dimensional ◽  
Tibial Slope ◽  
Knee Surgery ◽  
Radiographic Measurement ◽  
3D Measurement ◽  
Articular Surfaces ◽  
The Mean ◽  
Lateral Plateau

Abstract Background The tibial slope plays an important role in knee surgery. However, standard radiographic measurement techniques have a low reproducibility and do not allow differentiation between medial and lateral articular surfaces. Despite availability of three-dimensional imaging, so far, no real 3D measurement technique was introduced and compared to radiographic measurement, which were the purposes of this study. Methods Computed tomography scans of 54 knees in 51 patients (41 males and 10 females) with a mean age of 46 years (range 22–67 years) were included. A novel 3D measurement technique was applied by two readers to measure the tibial slope of medial and lateral tibial plateau and rim. A statistical analysis was conducted to determine the intraclass correlation coefficient (ICC) for the new technique and compare it to a standard radiographic measurement. Results The mean 3D tibial slope for the medial plateau and rim was 7.4° and 7.6°, for the lateral plateau and rim 7.5° and 8.1°, respectively. The mean radiographic slope was 6.0°. Statistical analysis showed an ICC between both readers of 0.909, 0.987, 0.918, 0.893, for the 3D measurement of medial plateau, medial rim, lateral plateau and lateral rim, respectively, whereas the radiographic technique showed an ICC of 0.733. Conclusions The proposed novel measurement technique shows a high intraclass agreement and offers an applicable opportunity to assess the tibial slope three-dimensionally. Furthermore, the medial and lateral articular surfaces can be measured separately and one can differentiate the slope from the plateau and from the rim. As three-dimensional planning becomes successively more important, our measurement technique might deliver a useful supplement to the standard radiographic assessment in slope related knee surgery. Level of evidence Level III, diagnostic study.

Rapid 3D measurement technique for colorful objects employing RGB color light projection

2020 ◽  
Vol 59 (7) ◽  
pp. 1907 ◽  
Author(s):  
Jianhua Wang ◽  
Yuguo Zhou ◽  
Yanxi Yang
Keyword(s):  
Measurement Technique ◽  
3D Measurement

scholarly journals 3D MEASUREMENT COMBINING MULTI-VIEW AND MULTI-FOCUS IMAGES USING LIGHT FIELD CAMERA

2020 ◽  
Vol V-2-2020 ◽  
pp. 633-640
Author(s):  
T. Fuse ◽  
Y. Kajihara
Keyword(s):  
Rigid Body ◽  
Light Field ◽  
Computational Photography ◽  
Measurement Time ◽  
3D Measurement ◽  
3D Measurements ◽  
Calculation Processing ◽  
Future Work ◽  
Shape From Focus

Abstract. In recent years, the demand for inexpensive, simple, and highly accurate 3D measurement has been increasing. Representative methods, photogrammetry, and shape from focus (SfF) have limitations in terms of measurement time and labour. In order to solve them, computational photography (CP) has been proposed. A light field camera, based on CP, has also been developed. It has a feature to acquire multi-view and multi-focus images simultaneously in one shot. It is possible to perform 3D measurements with less time and labour for photographing and calculation processing using these images. In this study, we combined the photogrammetry as applied to multi-view images with the SfF as applied to multi-focus images using a light field camera. We applied the proposed method to a rigid body and verified its accuracy. We confirmed that the proposed method achieved more accurate results than the photogrammetry and the SfF method. Furthermore, we applied the proposed method to screws and cracks on walls of buildings and affirmed its applicability. Finally, we suggested future work on the developed method.

scholarly journals Tibial torsion analysis in computed tomography: development and validation of a real 3D measurement technique

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Armando Hoch ◽  
Tabitha Roth ◽  
Magda Marcon ◽  
Philipp Fürnstahl ◽  
Sandro F. Fucentese ◽  
...  
Keyword(s):  
Measurement Technique ◽  
Measurement Method ◽  
Interobserver Reliability ◽  
Intraclass Correlation ◽  
Measurement Methods ◽  
3D Measurement ◽  
Tibial Torsion ◽  
Left And Right ◽  
3D Methods ◽  
Development And Validation

Abstract Purpose Pathological tibial torsion is known to negatively influence the functionality of the lower extremity, and therefore, its assessment might play an important role. While 3D imaging is used for many examinations of the musculoskeletal system, for the determination of tibial torsion no 3D measurement technique has been available so far. We developed a 3D measurement method and assess its interobserver reliability as well as its correlation with standard 2D measurement methods. Methods CT scans of 82 tibiae in 79 patients with a mean age of 41 years were included. A novel 3D measurement technique was developed and applied. Measurements were compared with two frequently used 2D measurement methods. ICC (intraclass correlation coefficient) for the new technique was determined and compared to the 2D measurement method. Furthermore, differences between left and right legs as well as between males and females were assessed. Results The ICC for the 2D methods was 0.917 and 0.938, respectively. For the 3D measurements, ICCs were calculated to be 0.954 and 0.950. Agreement between 2 and 3D methods was moderate to good with ICCs between 0.715 and 0.795. Torsion values for left and right legs did not differ significantly in 2D and in 3D (26.2 vs 28.5° and 27.2 vs. 25.9°). The same is true for the differences between male and female in 2D and 3D (26.2 vs. 29.6° and 25.0 vs. 31.2°). Conclusion The newly developed 3D measurement technique shows a high intraclass agreement and offers an applicable opportunity to assess the tibial torsion three-dimensionally.

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