A Comparison of Image Aligning and Correcting
Software with an Unmanned Aerial System
Kangsan Lee, Jinwoo Park, Jinmu Choi
gi.star@khu.ac.kr
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Contents
• Introduction
• Data Acquisition
– Image Gathering
– Correcting Lens Distortion
• Image Alignment
– Image Alignment Software
– Comparing Image Stitching Software
– Results
• Conclusion
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Introduction
• Why Unmanned Aerial System: Drone
 Aircrafts & Satellites: Major role in Remote Sensing
 Structural problems: Time, Cost and Weather condition
 UAS, Drone...?
• Purpose of study: Comparing image stitching softwares
 Variety of softwares in the market
 Each software was developed ‘On their own needs’
Q. What is the suitable program for small UAS system?
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Data Acquisition
• Image Gathering
– Hardware: 3DR Robotics IRIS+(Drone) and GoPro(Camera) are used
– Area of interest: Baramarae beach - west coast of South Korea
– App. 200 images are collected and used (Flight date: Jan, 2015)
Figure 1. IRIS+ and GoPro (Right), Mission Planner for autonomous flight (Left)
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Data Acquisition
• Correcting Lens Distortion
– GoPro(small digital camera) has a lens distortion (Tauro et al., 2014)
– Adobe Lightroom is selected to remove lens distortion
Figure 2. Lens distortion correction (before – later)
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Image Alignment
• Experimental Design
Image
Quality
Computing Environment
Processing
Time
Total Image
Volume
Table 1. Specification of the testing environment
Component
Specification
CPU
Intel Xeon CPU E3-1231 3.40GHz
RAM
16GB (DDR3, Dual Channel)
GPU
GeForce GTX 750Ti
Cuda Core
640
Storage
SSD, 256GB
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Image Alignment
• Image Alignment Software
– Five major software are selected to test about stitching performance
– Open-Source software(GPL); Hugin
– Commercial software; Photoscan, Photoshop, MS ICE, Pix4D
Table 2. Software information
Name
Photoscan
Photoshop
Image Composite
Editor
Developer
Agisoft
Adobe
Microsoft
License
Proprietary
Proprietary
Proprietary
Hugin
Pablo d'Angelo et al. GPL
Based on panorama tools
Pix4Dmapper
Pix4D SA
Optimized for UAS
(Free for
non-commercial use)
Proprietary
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Notes
Using photometry method
User-friendly interface
Variety of pre-defined
projection
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Image Alignment
• Comparing image stitching software
– The amount of input data has been changed; range from 50 to 200
Figure 3. Concept of software comparing experiment
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Image Alignment
Results
1) Processing Time
•
•
•
•
Gradually increased
MS ICE → Fastest
Hugin → X working: Software limitation
Photoshop → X working 150↑: Hardware limitation
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Image Alignment
2) Image Volume
• Image volume gradually increased according to numbers of images
• MS ICE exports the lowest volume
• Photoscan shows the highest rate of increase
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Image Alignment
3) Image Quality
•
Photoscan shows the best quality without any problem
•
MS ICE and Photoshop have some distorted
•
Pix4D cannot calibrate colour and image matching
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Conclusion
• Limitation
– Researchers can easily find alternative Open-Source software
– But the performance of open-source software does not reach to
commercial one
• Potential
– The potential of open-source software is sufficient
– E.g. Visual SFM became the best 3D image reconstruction open-source
software
• Future Market
– The sales market of UAS(Drone) have been increased
– Needs of image stitching will be increased in the near future
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Thank you