Background subtraction with variable illumination in outdoor scenes

Among the ultra-light elements B, C, N, and O nitrogen is the most difficult element to deal with in the electron probe microanalyzer. This is mainly caused by the severe absorption that N-Kα radiation suffers in carbon which is abundantly present in the detection system (lead-stearate crystal, carbonaceous counter window). As a result the peak-to-background ratios for N-Kα measured with a conventional lead-stearate crystal can attain values well below unity in many binary nitrides . An additional complication can be caused by the presence of interfering higher-order reflections from the metal partner in the nitride specimen; notorious examples are elements such as Zr and Nb. In nitrides containing these elements is is virtually impossible to carry out an accurate background subtraction which becomes increasingly important with lower and lower peak-to-background ratios. The use of a synthetic multilayer crystal such as W/Si (2d-spacing 59.8 Å) can bring significant improvements in terms of both higher peak count rates as well as a strong suppression of higher-order reflections.

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Running Gaussian Average as Method of Adaptive Background Subtraction in Radar Applications

2020 21st International Radar Symposium (IRS) ◽

10.23919/irs48640.2020.9253804 ◽

2020 ◽

Author(s):

Michail Drozdov ◽

Borisas Levitas

Keyword(s):

Background Subtraction ◽

Radar Applications

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Detect and Extract multi-object Using Background Subtraction

International Journal of Recent Advancement in Engineering & Research ◽

10.24128/ijraer.2017.jk56kl ◽

2017 ◽

Vol 2 (12) ◽

pp. 1

Author(s):

Jyoti patel

Keyword(s):

Background Subtraction

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Effects of background substraction on differential kidney function measured by static scintigraphy with DMSA and dynamic scintigraphy with MAG 3

Nuklearmedizin ◽

10.3413/nukmed-0056 ◽

2008 ◽

Vol 47 (01) ◽

pp. 43-47 ◽

Cited By ~ 1

Author(s):

A. Smokvina ◽

S. Grbac Ivanković ◽

V. Licul ◽

N. Girotto

Keyword(s):

Kidney Function ◽

Background Subtraction ◽

Background Activity ◽

Ratio Method ◽

Uptake Ratio ◽

Kidney Size ◽

Significant Difference ◽

Laboratory Changes ◽

Dynamic Scintigraphy

SummaryThe aim of this study was to assess the influence of background subtraction (BS) on estimation of differential kidney function (DF) on the static scintigraphy with 99mTc dimercaptosuccinic acid (DMSA) and dynamic scintigraphy with 99mTc mercaptoacetyltriglicine (MAG3) and to establish possible differences between DF values estimated with these methods. Patients, methods: Patients (n = 106) were selected among those scheduled to static and dynamic scintigraphies within 3 months, with no interim clinical and laboratory changes, regardless the kidney pathology. DF was estimated according to the uptake ratio method. Four background regions of interest (ROIs) were applied, identical for both studies, and DF values were recalculated after BS. The corrected values were compared to the values before correction, separately for DMSA and MAG3, and between the studies. The results showed that ROIs used introduce variable results for the same patients, predominantly when noncorrected DF values were <45%. There were no significant differences between DF values (corrected and noncorrected) obtained from static and dynamic scintigraphy in all groups of patients. Since numerous reasons can bring to the errors in DF estimation when BS is used, the conclusions are that it would probably be more accurate to avoid BS, particularly when DF values are compared in a patient follow-up, and when kidney function is normal. BS should be used, but always in the same way, only when there is a significant difference in kidney size, or when DF is <25%, since background activity is then considerable. MAG3 and DMSA can be equally used for DF estimation and their results compared in patient follow-up.

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