Sequential image analysis and measurement of pigmented lesions: false variations due to patient positioning

2003 ◽  
Vol 28 (6) ◽  
pp. 657-660
Author(s):  
F. Vazquez-Lopez ◽  
J. A. Manjón-Haces ◽  
M. Lopez-Escobar ◽  
N. Perez-Oliva ◽  
A. A. Marghoob
PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4467 ◽  
Author(s):  
Lauren Arona ◽  
Julian Dale ◽  
Susan G. Heaslip ◽  
Michael O. Hammill ◽  
David W. Johnston

The use of small unoccupied aircraft systems (UAS) for ecological studies and wildlife population assessments is increasing. These methods can provide significant benefits in terms of costs and reductions in human risk, but little is known if UAS-based approaches cause disturbance of animals during operations. To address this knowledge gap, we conducted a series of UAS flights at gray seal breeding colonies on Hay and Saddle Islands in Nova Scotia, Canada. Using a small fixed-wing UAS, we assessed both immediate and short-term effects of surveys using sequential image analysis and between-flight seal counts in ten, 50 m2 random quadrats at each colony. Counts of adult gray seals and young-of-the-year animals between first and second flights revealed no changes in abundance in quadrats (matched pair t-test p > 0.69) and slopes approaching 1 for linear regression comparisons (r2 > 0.80). Sequential image analysis revealed no changes in orientation or posture of imaged animals. We also assessed the acoustic properties of the small UAS in relation to low ambient noise conditions using sound equivalent level (Leq) measurements with a calibrated U-MIK 1 and a 1/3 octave band soundscape approach. The results of Leq measurements indicate that small fixed-wing UAS are quiet, with most energy above 160 Hz, and that levels across 1/3 octave bands do not greatly exceed ambient acoustic measurements in a quiet field during operations at standard survey altitudes. As such, this platform is unlikely to acoustically disturb gray seals at breeding colonies during population surveys. The results of the present study indicate that the effects of small fixed-wing UAS on gray seals at breeding colonies are negligible, and that fixed-wing UAS-based approaches should be considered amongst best practices for assessing gray seal colonies.


2006 ◽  
Vol 62 (3) ◽  
pp. 558-566 ◽  
Author(s):  
Nobuo SANO ◽  
Tetsuo ITO ◽  
Koji BABA ◽  
Kazuo NISHIMURA ◽  
Isamu YOSHITAKE ◽  
...  

1994 ◽  
Vol 16 (1) ◽  
pp. 103 ◽  
Author(s):  
Perotti R. ◽  
Biagioli M. ◽  
Burroni M. ◽  
Santini S. ◽  
DellʼEva G. ◽  
...  

2013 ◽  
Vol 365-366 ◽  
pp. 482-485
Author(s):  
Rui Li ◽  
Ping Xu ◽  
Yuan Mu Zhong ◽  
Long Xi Liu

As the impact process of train energy absorbing components occurs in a short time, high-speed cameras are used to record it and the amount of deformation and energy change of the energy absorbing components can be obtained by analyzing sequential images. The method of sequential images analysis presented is based on feature recognition of mark points by template matching method. In addition to this, error introduced by the camera positions is corrected to obtain more exact results. During the process of collision, the amount of its deformation is 52mm and its energy change is 2.69KJ when using the sequential image analysis.


1996 ◽  
Vol 16 (Supplement2) ◽  
pp. 31-34
Author(s):  
Motonobu YOSHIMOTO ◽  
Tomomasa UEMURA

1998 ◽  
Vol 84 (1) ◽  
pp. 29-32 ◽  
Author(s):  
Stefano Tomatis ◽  
Aldo Bono ◽  
Cesare Bartoli ◽  
Gabrina Tragni ◽  
Bruno Farina ◽  
...  

Aims and background A study was carried out to evaluate the effectiveness of image analysis performed by the two color representation models when a computer-assisted diagnosis of melanoma is involved. Methods Color images of 40 skin pigmented lesions, which included 12 melanomas, were acquired by a standard color RGB video camera and stored in a PC for off-line processing. Image analysis was performed in the red green and blue color representation model and using hue and saturation color components. To describe shape and color characteristics of each lesion, including area, roundness and color variegation, 16 parameters were derived from red, green, blue, hue and saturation color planes and tested as possible variables useful to differentiate melanomas from benign nevi. Results The test gave a result of significance for six of the 16 derived image descriptors. The general trend of our data was in agreement with clinical observations according to which melanoma is usually darker, more variegated and less round than a benign nevus, whereas lesion dimension of melanomas and benign lesions was not significantly different. Conclusions Our preliminary results suggested that image analysis performed on hue and saturation-derived and red green and blue-derived data could better discriminate melanoma from nevi than separately using the two color representation models.


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