Fish-Eye Camera for Shading Analysis in Forests

Innovative/Smart Color and Spectral Imaging in Industry, Biology and Medicine Fish-Eye Camera for Shading Analysis in Forests • Introduction • Basic...
Author: Joan McCormick
1 downloads 0 Views 2MB Size
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

15

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

50

0

10

20

30

40

50

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

P.22