ENGLISH

21卷/3期

21卷/3期

華藝線上圖書館

Pages:

139-149

論文名稱

航攝數位影像陰影資訊分析及其在林地分類之應用

Title

Shadow Information Analysis of Digital Aerial Images and Its Application of Forestland Classification

作者

謝依達, 鍾玉龍, 陳朝圳

Author

Yi- Ta Hsieh, Yuh- Lurng Chung, Chaur-Tzuhn Chen

中文摘要

森林資源調查扮演森林經營管理與監測的重要關鍵,隨著空間資訊獲取方法的日新月異,利用航遙測分析技術於森林資源調查與監測已有具體成效。然而在遙測影像在拍攝過程中,會受太陽角度、地形起伏、地物遮蔽等因素影響而產生陰影,並影響影像品質。事實上,在航遙測光學影像中,陰影一直被視為變遷分析與影像分類等應用層面的影像雜訊,經常導致分析結果之準確度受到影響,因此影像陰影區域處理為被視為一項重要的研究課題。近年來空載多光譜遙測儀器可獲取高空間、高輻射解析力資料,如Leica ADS-40、Intergraph DMC等多光譜航測影像,皆可獲得12-bit以上的輻射解析力(Digital Number: 0–4,095),輻射解析力的增加對於陰影區域之解釋提供了極高的潛力。有鑑於此,本研究進行陰影區域的土地覆蓋分類,並採用四種陰影補償技術輔助後續分類(方法1,13-bit 陰影光譜資訊; 方法2,線性相關校正陰影補償技術; 方法3,值方圖匹配陰影補償技術; 方法4, 多元資料融合陰影補償技術),並比較各方法之優劣。研究結果指出,在進行陰影區域的土地覆蓋分類的結果中,其中方法1(13-bit 陰影光譜資訊)與方法2(線性相關校正陰影補償)所得結果較佳(90%以上的總體精確度),成果證明13-bit的高輻射解析力航攝數位影像具有足夠資訊勝任陰影區域土地覆蓋分類。

Abstract

Forest resource inventory plays a key role in forest management and monitoring. Using photogrammetry and remote sensing techniques in forest resource inventory has obtained significant results such as getting the spatial information of forest. However, during the image capturing process, numerous influential factors hinder the quality of these images, such as the shadows caused by the different angle of the sun, terrain features, and surface object occlusion. Furthermore, the shadows in optical remote sensing images are regarded as image nuisances in numerous applications, specifically, change detection and image classification frequently affecting the accuracy of analytical results. Therefore, research on shadow processing in images is highly valued. In recent years, airborne multispectral aerial image devices have been developed high radiometric resolution data, including Leica ADS-40, Intergraph DMC. These devices are capable of capturing radiometric resolution images of 12 bits or higher, for example, a 12-bit digital number (DN) ranged from 0–4,095. The increased radiometric resolution of digital imagery provides more radiometric detail of potential use in classification or interpretation of land cover of shadow areas. Therefore, the classification of the shadow areas was tested by using four compensation methods (Method 1, used 13-bit spectral information in shadow area for classification; Method 2 used Linear Correlation Correction (LCC) before the classification; Method 3 used Histogram Matching (HM) before the classification, and Method 4 used Multi-Source Data Fusion (MSDF) to aid in classification of shadows.), and compared the benefits of those shadow compensation methods. The results indicated that Method 1 (13-bit high radiometric resolution images; no treatment) and method 2 (LCC) presented better land cover classification results and possessed significant accuracy (over 90% of overall accuracy), and this result further demonstrates that the 13 bit high radiometric resolution images (ADS-40) have sufficient information to satisfy classification of shadow areas.

關鍵字

高輻射解析力、土地覆蓋分類、陰影偵測、陰影補償

Keywords

high radiometric resolution, land cover classification, shadow detection, shadow compensation

附件檔名

華芸線上圖書館

http://www.airitilibrary.com/Publication/alPublicationJournal?PublicationID=10218661&type=P001

備註說明

N / A

Pages:

151-161

論文名稱

運用離散小波轉換表達影像特徵線的新方法

Title

A DWT-Based New Method for Representation of Image Feature Lines

作者

蔡展榮

Author

Jaan-Rong Tsay

中文摘要

本篇論文提出一個新方法來表達一般的影像特徵線,它是從離散小波轉換演化設計而得。本文使用有限承載正則哈爾和多布吉斯小波來進行實驗測試,其中,影像特徵線是採用小波推導出的對稱梯度運算元並搭配「過零法(zero-crossing)」發展出的自動化影像邊緣線偵測法求定而得。測試結果顯示,使用此方法可以靈巧地表達影像特徵線,而且依據所需的精度要求來準確表達影像特徵線,當中的計算參數可以自動決定。此外,簡明具體的離散小波轉換公式和離散小波重建公式也一併於文中載明。

Abstract

This paper presents a Discrete Wavelet Transform (DWT) based new method for representation of image feature lines. Some tests are done by using the compactly supported orthonormal Haar and Daubechies wavelets, where image feature lines are automatically generated by an automatic edge detection method which utilizes wavelets-derived symmetric gradient operators and wavelets-based zero-crossing approach, and used as test data. Test results show that feature lines on a 2D image plane can be represented in a flexible manner by the proposed method. The representation can be done as accurately as needed, where the related parameters can be determined automatically. In addition, explicit and user-friendly formulas of DWT and Discrete Wavelet Reconstruction (DWR) are also given in this paper.

關鍵字

離散小波轉換、影像特徵線、離散小波重建、子波編碼、小波縮減

Keywords

Discrete Wavelet Transform (DWT), image feature line, Discrete Wavelet Reconstruction (DWR),subband coding, wavelet shrinkage

附件檔名

華芸線上圖書館

http://www.airitilibrary.com/Publication/alPublicationJournal?PublicationID=10218661&type=P001

備註說明

N / A

Pages:

163-182

論文名稱

無人飛航載具監測環境污染之功能

Title

Monitoring of Environmental Pollutants by Using Unmanned Aerial Systems

作者

賈澤民

Author

Jir-Ming Char

中文摘要

本文係探討利用無人航行載具作為環境污染監測之新技術,環境污染範圍可包含空污及水污等,空污者計有臭氧、二氧化氮、PM2.5懸浮微粒及非甲烷碳氫化合物(NMHC)等;水污者則包括廢水偷排放引起水質的物理、化學或生物特性的變化等。其中無人飛航載具攜帶空氣污染物偵測分析儀器之搭載平台,曾對高雄市大林蒲地區上空之空氣品質變化進行立體即時之量測。無人飛航載具全機採碳纖維複合材料製作,並採模組化設計以達到輕量化、高強度之特性;另搭載GPS自動導航系統與射頻數據傳輸模組,能將偵測數據即時結合環境地圖,以顯示現地之污染物即時濃度變化。由於無人飛航載具於空中高速飛行時會因靜壓降低而造成採樣儀器無法有效採樣,故須設計一空氣膨脹室將機外氣流減速並升壓,以提供採樣儀器理想之氣流狀態。除此之外,為排除碳纖機身材質對無線電波造成之遮蔽效應,亦對無線傳輸天線進行模擬與最佳化設計以增進傳輸效能,其所採行技術在國內外皆屬新創。另在水污染偵測管制方面,可用飛翼船搭配氣體偵測及水質採樣等儀器對重大污染水域定期長時間偵察,所開發之飛翼船係結合飛機與船舶之整體設計並採用複材之特殊結構,能於水面及近水面上空高速航行並進行採樣與觀測水污染等任務。這些無人航具所偵獲之立體即時污染數據再結合雲端資料庫,將來可運用在政府或業界處理環境監控相關之管制作為與緊急應變任務。

Abstract

The objective of the present research is using Unmanned Aerial Vehicle System (UAVS) to probe the spatial and time variations of the pollutants in the air and water realm. In the air portion is to evaluate the performance of O3, NO2 and NMHC measurements using UAVs in Kaohsiung city. In the water portion, the pollutants discharged from factory waster water will be discussed. In this paper, a high-performance, long-endurance UAV system is developed to provide a platform for three-dimensional pollution measurement and monitoring requirements. The system includes carbon fiber composite airframe, GPS navigation, autopilot, RF data transmission and integrated air pollution sensing systems. The efficiency of each system are optimized and verified through numerical simulation or experiments, and interfaces between UAV and air pollution sensing systems are also considered to provide ideal air flow to the sensor under the extreme conditions at high altitude and high speed. Therefore, the UAV system can display air pollution measurement changes in real time and combine these results with GPS and geography data to monitor air quality in three dimension space. The air sensing results are compared with data from ground monitoring site. The result shows that the UAV system can offer real-time, 3-dimensional, and large area measuring results, which can obtain useful data for the government, industry, and research units. Also, when the water in our rivers, lakes, and oceans becomes polluted, the effects will be far reaching. It can endanger wildlife, make our drinking water unsafe. No doubt we need a more reliable tool to monitor the polluting water. Therefore a platform composed of the technologies of : Wing-In-Ground craft, the water-detecting sensors, the IT skill, and the cloud-computing service were bundled for this purpose . This platform can execute smart 3D UAV-based detecting technology of water pollution, and would be useful to make the coastal and river basin management more efficient.

關鍵字

無人飛航載具、飛翼船、空氣品質監測、水污染

Keywords

UAV, WIG craft, air quality monitoring, water pollution

附件檔名

華芸線上圖書館

http://www.airitilibrary.com/Publication/alPublicationJournal?PublicationID=10218661&type=P001

備註說明

N / A

Pages:

183-197

論文名稱

應用透視投影轉換進行微型化多相機陣列之波段套合

Title

Band Registration for Miniature Multiple Camera Array through Perspective Transformation

作者

詹鈞評, 饒見有, 黃倬英, 劉暹, 李文慶

Author

Jyun-Ping Jhan, Jiann-Yeou Rau, Cho-Ying Huang, Kircheis Liu, William Lee

中文摘要

微型化多相機陣列(Miniature Multiple Camera Array, MiniMCA)是由多個鏡頭組成的多光譜框幅式相機,能記錄可見光至近紅外光波譜資訊,且由於體積小重量輕,因此可藉由無人飛行載具 (Unmanned Aerial Vehicle, UAV)獲取高空間與時間解析度的多光譜遙測影像。MiniMCA因每個鏡頭之透視中心與觀測方向皆不同,不僅各鏡頭具有不同的透鏡畸變量,且相機之間亦存在著旋轉與平移的幾何轉換關係,使得原始多光譜影像具有很大的波段錯位現象。因此本研究提出MiniMCA相機的波段套合程序,首先藉由室內相機率定求得各相機之內方位與相對方位參數,進而得到透鏡畸變修正與透視投影轉換參數,接著將所有副鏡頭之影像轉換至主鏡頭之像空間,最後結合系統性誤差修正(含平移與透鏡畸變修正)達到波段套合的目的。研究成果顯示經透視投影轉換與系統性誤差修正後相鄰波段間的平均套合誤差皆在0.2-0.5個像元之間,證明本研究提出之波段套合程序其精確度可符合遙感探測應用之需求。

Abstract

Miniature Multiple Camera Array (MiniMCA) is a frame-based multispectral sensor, which compose of multiple cameras with different filters to acquire images range from visible light to near infrared. Due to its light weight and small size, it is suitable for mounting on an Unmanned Aerial Vehicle (UAV) for acquiring high spatial, high temporal, and multispectral imagery. However, since all cameras have different perspective centers and view directions as well as different lens distortion effects, which will result in significant band-misregistration phenomena on the original images. In this study, a band registration scheme based on perspective transformation is thus proposed for MiniMCA sensor. It starts from indoor camera calibration to obtain the interior orientation parameters (IOPs) and relative orientation parameters (ROPs). Next, the slave images are transferred into the master camera’s image space through perspective transformation, where the coefficients are directly acquired from the estimated IOPs and ROPs. In the end, a systematic error correction (including displacement removal and lens distortion correction) is adopted to minimize the band misregistration effect. Through visual comparison and quantitative accuracy assessment, the experimental results show that the average of band misregistration errors are between 0.2 - 0.5 pixels, which proves that the accuracy of the proposed scheme is accurate and satisfy the demand of remote sensing applications.

關鍵字

多相機陣列系統、多光譜影像、無人飛行載具、波段套合

Keywords

MiniMCA, multispectral image, UAV, band registrati

附件檔名

華芸線上圖書館

http://www.airitilibrary.com/Publication/alPublicationJournal?PublicationID=10218661&type=P001

備註說明

N / A

Pages:

199-211

論文名稱

開放街圖之三維建物模型品質評估:以交通大學校區為例

Title

Quality Assessment of the 3D Building Models from OpenStreetMap: A Case Study of NCTU Campus

作者

張智安, 謝旻哲

Author

Tee-Ann Teo, Min-Che Hsieh

中文摘要

自願性地理資訊(Volunteered Geographic Information, VGI)為地理資訊領域重要的空間資料來源之一,其特點為志工繪製、資料更新便利及資料開放。VGI的資料品質為一重要的議題,本研究建立開放街圖(OpenStreetMap, OSM)之三維建物模型驗證程序並驗證其精度,由OSM平台擷取群眾力量建立的三維建物模型,與專業測繪人員使用航照立體像繪製的三維建物模型進行比較分析,分析比較包含建物模型的完整性、形狀差異、面積差異及樓高差異。本研究選定區域為新竹市交通大學,OSM建物模型由該校學生志工繪製,實驗分析成果顯示建物數量的完整性超過90%;形狀差異主要為建築物輪廓的細緻度;僅二棟建物樓高差異大於一層樓;建物面積差異值多小於30%。本研究成果顯示,由學生志工在特定區域繪製的三維建物模型,可滿足小比例尺繪圖的應用需求。

Abstract

Volunteered Geographic Information (VGI) has become an important geospatial data source for GIS applications. The data quality of VGI is an important issue as it is produced by non-professional volunteers. The objectives of this study are to establish the evaluation procedure and analyze the data quality for 3D building models of National Chiao Tung University (NCTU) from Open Street Map (OSM). The reference 3D building models are measured by professional mapping agency using stereo aerial images. The evaluation procedure includes completeness, shape analysis, surface distance analysis and building story analysis. In the experiments, the completeness of building model reached 90%; the shape difference usually occurred on small building parts; only two buildings showed height difference larger than 1 floor; most of the surface distance was better than 30%. The experimental results indicated that the 3D building models from OSM may satisfy the needs of small scale mapping in particular areas.

關鍵字

自願性地理資訊、開放街圖、三維建物模型

Keywords

volunteered geographic information, OpenStreetMap, 3D building model

附件檔名

華芸線上圖書館

http://www.airitilibrary.com/Publication/alPublicationJournal?PublicationID=10218661&type=P001

備註說明

N / A

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