Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
• Introduction • Basics • Materials and Methods • Experiments and Results
Fish-Eye Camera for Shading Analysis in Forests
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
(Fish-Eye Imaging System for analysis of Light Environments under Forest Canopies)
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.1
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
David Pryor PhD - Introduction • Introduction • Basics
1989-1999 University Goettingen – (Light) radiation measuring systems for ecological research work. – Dataloggers, PAR sensors
• Materials and Methods
Studied electrical engineering – Telecommunications – Light Metrology (Lichtmesstechnik) – FH-Hannover
• Experiments and Results
1997-2002 Working as a research assistant – FH-Hannover Fields of work: 1) Colour Metrology and 2) Radiation Metrology 2003 Founder and Managing Director of the ColorLite GmbH Company We develop and produce Handheld Spectrophotometers and Industrial Spectrophotometers for online colour measurement
2010 PhD in the field of (Light) Radiation Metrology ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.2
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Solar radiation assessment in forests …why? • Introduction • Basics • Materials and Methods • Experiments and Results
for ecological and biological research - light resources are of fundamental importance plant growth natural forest management - natural rejuvenation
verifiable and objective measurement of - forest damage ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.3
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Solar radiation assessment in towns and cities for… • Introduction • Basics • Materials and Methods • Experiments and Results
planning photovoltaic systems in urban areas
architectural planning making use of the natural energy source of the Sun
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.4
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Problems determining the potential solar radiation available • Introduction
Radiation levels are not only dependent on the surrounding topography but...
• Basics • Materials and Methods • Experiments and Results
...weather, time of day and time of year
E(W/m²)
6:00
12:00
20:00
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.5
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
• Introduction
…and the solar radiation must be differentiated between, direct sun light and diffuse sky light
• Basics • Materials and Methods • Experiments and Results
direct
diffuse
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.6
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Methods in use to date: 1) subjective method through a surveyor • Introduction • Basics • Materials and Methods • Experiments and Results
Commonly used, simple but inaccurate
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.7
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
2) Instantaneous measurements with radiation (PAR) meters
• Introduction
923
• Basics
1.23
• Materials and Methods • Experiments and Results
-
Disadvantage: simultaneous reference measurement „without obstructions“ is needed only diffuse radiation can be measured this way
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.8
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
3) Long-period measurements with radiation sensors and data-loggers or integrating radiation meters • Introduction • Basics 1.23 • Materials and Methods • Experiments and Results
Disadvantage: - time consuming, costly and high data flow - distinguishing between direct and diffuse radiation difficult ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.9
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Hemispherical photography method
• Introduction • Basics • Materials and Methods • Experiments and Results Image recorded in 1951 by Evans and Coombe to demonstrate the effect of sky conditions on results (Evans & Coombe 1959)
Image recorded at exactly the same position as the left image but under a clear sky (Evans & Coombe 1959)
„Fisheye“ images are recorded with the camera looking from under the trees skywards
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.10
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Indirect (diffuse) site factor - ISF
• Introduction • Basics • Materials and Methods • Experiments and Results
The image is segmented into sky areas and obstacle areas The image is divided into rings with zenith as the point of origin Ring radii are calculated to compensate for lens distortion and angle of incidence The relative sky area within each ring is calculated. The diffuse site factor is the average of all rings
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.11
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Direct site factor - DSF
• Introduction
The path of the Sun for a chosen period is projected onto the fisheye image
• Basics • Materials and Methods • Experiments and Results
Openings in the canopy are counted and set in relation to the Sun path without shading
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.12
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
In summary - Hemispherical photography method has…
• Introduction • Basics • Materials and Methods • Experiments and Results
Advantages: - Single measurement is required to predict the available solar radiation - Direct and diffuse radiation are differentiated
Disadvantages: - Extremly low accuracy in dark woodlands and - Low precision because of a dependency on sky lighting and the subjectivity of the analysis process
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.13
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Drawbacks of the hemispherical photography method can be significantly reduced by: • Introduction
1) The implementation of a logarithmic high-dynamic-range image sensor for image acquisition
• Basics • Materials and Methods • Experiments and Results
The digital cameras in use today have a relative low dynamic range approx. 72dB (1:4000) compared to 120dB (1:1000 000) of a logarithmic sensor
• Greatly improve the accuracy in dark woodlands • Reduce the restrictions on sky conditions that limit circumstances necessary for gaining reproducible results
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.14
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
2) Integrating all components required to record and analyse the surrounding topography, in a closed system, controlled by custom made hardware • Introduction • Basics • Materials and Methods • Experiments and Results
•Exposure settings assignment can be optimised for this special application •The integration of a digital compass enables an automatic objective evaluation of the images • Being able to observe measured results immediately on site would also increase reliability as an immediate plausibility check is possible
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.15
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Embedded PC segmentation calculation of site factors • Introduction • Basics
Digital compass to determine North Pole position
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
180° - Fisheye lens CMOS- image sensor logarithmic response
• Materials and Methods • Experiments and Results
Overview
Digital spirit level for automatic start
Electronic circuit frame grabber for fast capture
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.16
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Measurements in a dark (ISF = 2-3%) deciduous woodland
• Introduction • Basics • Materials and Methods • Experiments and Results
Grey image made with new System (ISF = 2-3%)
Binarised image
Same position scan made with conventional system
Binarised image
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.17
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Measurements in a dark (ISF = 2-3%) deciduous woodland
• Introduction • Basics • Materials and Methods • Experiments and Results
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
Grey value image from new system displaying opening in the canopy
Grey image recorded with conventional system section enlarged
Same section with red areas classified as sky areas
Same section with white area classified as sky areas
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.18
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Results: measurements made in a dark deciduous woodland Test System
50
• Basics
40
• Materials and Methods • Experiments and Results
DSF [%]
• Introduction
PAR LI-190
Conventional System
30 20 10 0 0
5
10
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20
25
30
Direct comparison of the two hemispherical photography systems and a reference recorded with PAR sensors
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.19
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
Results: measurements made in a dark deciduous woodland Conventional System vs PAR
• Introduction
• Experiments and Results
60
R² = 0.711
50
R² = 0,9624
50 ISF Test System
• Materials and Methods
ISF Conventional System
• Basics
Test System vs PAR
60
40 30 20 10
40 30 20 10
0
0 0
10
20
30
40
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ISF PAR Values
ISF PAR Values
Comparison of ISF measured with PAR sensors and values from the test system
Comparison of ISF measured with PAR sensors and values from the conventional digital system
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.20
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
The experiments have shown that the new test system: • Introduction
Has an improved overall precision
• Basics
Has an improved precision under varying sky conditions
• Materials and Methods • Experiments and Results
Shows a greatly improved accuracy under dark canopies. Conventional digital systems that are in use to date, suffer from extreme inaccuracy in dark (site factors < 15%) forests. Enables images to be automatically analysed direct at the point of interest. Immediate results also enable a validity check, so that scanning can be repeated if necessary
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
P.21
Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine
Fish-Eye Camera for Shading Analysis in Forests
• Introduction • Basics • Materials and Methods • Experiments and Results
Thank You
ColorLite GmbH Innovative colour metrology
Dipl.-Ing., PhD. David Pryor +49 (0) 5552 999 580 +49 (0) 5552 999 589
[email protected] www.colorlite.de
14th - SpectroNet Collaboration Forum 2012 5th September 2012, Jena, Germany
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