ENGLISH

7卷/4期

7卷/4期

華藝線上圖書館

Pages:

1-16

論文名稱

時頻濾波器過濾影像雜訊之效果

Title

Time-Frequency Filters and Their Results on Image Noise Filtering

作者

紀凱屏 , 蔡展榮

Author

Kay-Ping Chi , Jaan-Rong Tsay

中文摘要

本文探討各種不同的影像雜訊過濾方法,包括空間域的方法、頻率域的方法、時頻域的方法。並以影像復原概念為基礎,將五張不同類型的實驗影像分別加入隨機雜訊(如:高斯雜訊、斑駁雜訊、椒鹽雜訊)、系統性雜訊(如:相干雜訊),文末再以時頻域中的Daubechies 小波法過濾衛載合成孔徑雷達影像為例,綜合分析各法過濾影像雜訊的效果。由實驗結果可看出應用時頻域的方法過濾雜訊確實是可行的,其中,空間濾波器與 Daubechies 小波法皆能有效的過濾高斯雜訊與斑駁雜訊;椒鹽雜訊則以空間濾波器的中值濾波器效果最好;而相干雜訊的部分以頻率濾波器中的帶阻濾波器效果最好。

Abstract

In this paper, we discuss different approaches for reducing image noise, including filtering image noise in spatial domain, frequency domain, and time-frequency domain, and estimate their denoising effect. We use a spaceborne SAR (=Synthetic Aperture Radar) image and add several kinds of noise in five different test images under the theoretical concepts of image restoration. They include (1) random noise such as Gaussian noise, speckle noise and salt-and-pepper noise, and (2) systematic noise such as coherent noise. The results demonstrate that Daubechies wavelet approach is efficient. Spatial filters and Daubechies wave-let approach can filter out the Gaussian and speckle noise well. Median filters are good ones for reducing salt-and-pepper noise. Bandreject filters are suitable for filtering out the coherent noise.

關鍵字

時頻濾波器、影像雜訊、影像復原、小波轉換

Keywords

time-frequency filter, image noise, image restoration, wavelet transform

附件檔名

華芸線上圖書館

N / A

備註說明

200206-7-4-1-16

Pages:

17-40

論文名稱

以統計模式進行地形資料的融合及變遷偵測

Title

Fusion of Terrain Data Sets and Change Detection by Statistical Approach

作者

黃宗仁 , 趙鍵哲

Author

Tsung-Jen Huang , Jen-Jer Jaw

中文摘要

因工程需求,地形監控或災害評估等目的,地形資料之生產頻繁,故同一地區之地形資料來源廣泛(經由不同單位、不同時間測取)。儘管在點位密度、取樣位置及地形資料精度上,各資料間有所差異,其獲取地形資料而所重複投入之人力、財力卻是不爭的事實。因此從實用觀點上出發,如何有效地融合諸多「重複觀測」之地形,而衍生出一套更佳之地形估值;甚至在融合過程的歧異現象上,歸結並偵測出地形變遷的事實,據以提供政府部門或各個工程機關使用,遂成為本研究探討之重點。 地形資料融合之精義在於資料間的相互比對繼而整合,因此某些系統性的問題,例如地形變遷,便會在資料比對的過程中彰顯出來。而純屬隨機部分、穩定的地形資料便可藉助融合的處理,產生更佳的地形估值(即更佳的地形精度及可靠度)。本研究將地形視為一種訊號,為考量保留最原始資料量測精度,融合的邏輯不藉助任何型式的內插方式(除非地形可以某種數學函數描述之),不限定資料本身的型式,以統計的工具進行地形資料的融合及變遷報導。

Abstract

The highly repeated observations, multi-temporal or multi-source, of terrain data for a specific area can be often seen due in great part to the purposes of civil activities, topographic monitoring and damage evaluation, etc. They may seem to vary in point density, sampling strategies and accuracy as well, though. From economic point of view, deriving a better estimation of terrain information by fusing the homogeneous terrain data sets may draw great attention both for research and practical interest. As a by-product of that, the topographic change could be also detected accordingly based on the disagreement via fusing procedures. The central principle of fusing terrain data sets stems from cross check, thereby signaling out system­atic problems such as topographic change, among them and keeping steady terrain data sets combined and resulting in an updated terrain data with better accuracy and reliability. The proposed method for fusion of terrain data sets and change detection employs the statistical approach which features in making no as­sumption of the terrain characteristics and without relying on any specific data format. The preliminary results show satisfactory performance based on the evaluations in efficiency and accuracy aspect.

關鍵字

地形變遷、融合過程、相互比對

Keywords

Topographic Change, Fusing Procedures, Cross Check

附件檔名

華芸線上圖書館

N / A

備註說明

200206-7-4-17-40

Pages:

41-52

論文名稱

水稻單葉光譜特徵與葉綠素濃度之關係

Title

Changes of Spectral Characteristics to Chlorophyll Concentration in Rice Leaves

作者

李裕娟 , 楊純明

Author

Yuh-Jyuan Lee , Chwen-Ming Yang

中文摘要

本文研究係在行政院農業委員會農業試驗所農場(臺中縣霧峰鄉)進行,以四個水稻(Oryza sativa L.)品種為試驗材料,測定 1998 年一、二期稻作全生育期間之稻株單葉高解析光譜(350-1100 nm,頻寬 2 nm) ,以探討與葉片葉綠素有關之光譜特徵,並以建立單葉光譜特徵與葉綠素濃度之量化關係。在稻株單葉之光譜性質中,穿透比值(transmittance) 及反射比值(reflectance)乃直接量測,而吸收比值(absorptance)則由此估算。試驗結果發現,四個參試水稻品種之單葉光譜紅光波段及藍光波段計有四條與葉綠素高相關之特徵波長,這些特徵波長之吸收比值與葉片葉綠素總量(total chlorophyll)呈曲線正相關,反射比值則呈曲線負相關,且在兩期稻作皆然;其中以紅光波段 664、652 及 644 nm 之決定係數(R2)高於藍光波段之 434 nm 。依照光譜特徵與葉綠素回歸程式所估算之葉綠素值與實際測定值之相關係數達極顯著水準(1 %)。參試四個水稻品種之單葉光譜特徵與葉綠素濃度之相關具有品種間差異,臺中在來一號(TN1)和臺農 67 號(TNG67)之相關性高於臺梗 8 號(TK8)和臺中秈10號(TCS10)。單葉光譜性質與葉綠素 a 及葉綠素 b 之關係一如葉綠素總量,吸收比與葉綠素 a 及葉綠素 b 呈現曲線正相闕,而反射比則與葉綠素 a 及葉綠素 b 呈現曲線負相關。無論吸收比或反射比,其與葉綠素 a 及葉綠素 b 之曲線關係均以 644 nm 之決定係數最高,以 434 nm 之決定係數最低。綜合上述結果,稻株單葉光譜性質具有被利用於估測葉綠素濃度之可行性,不受期作別影響,未來可據以利用於快速檢測與估測水稻葉片及植體葉綠素濃度或含量。

Abstract

Field experiments were conducted at the experimental farm of Taiwan Agricultural Research Institute, Wufeng, to identify spectral characteristics in associated with chlorophyll concentration in rice leaves and to establish their quantitative relationships. There were 4 rice cultivars grown in the 1st and the 2nd crops of 1998. In leaf optical property, transmittance (t) and reflectance (r) were measured by an external integrating sphere in connected to a spectroradiometer, and absorptance (a) was calculated by a=l-t-r. It was found that 3 wavelengths (664,652 and 644 nm) in the red light region and 1 wavelength (434 nm) in the blue light region were associated with total chlorophyll in rice leaves. The absorptance was positively correlated, while the reflectance was negatively correlated, to the change of total chlorophyll in both cropping seasons. The determining coeffcients (R2) for wavelengths in the red region were greater than that in the blue region, yet the values were cultivar dependent. The relationships between absorptance and reflectance and chlorophyll a and chlorophyll b were also correlated curvilinearly. It was a positive relationship for absorptance and a negative for reflectance. The coefficient of determination for 644 nm was higher than that for 434 nm. Results suggest that optical property of rice leaf may be used to estimate chlorophyll concentration in either cropping season.

關鍵字

水稻、光譜特徵、吸收比值、反射比值、葉綠素濃度

Keywords

Rice (Oryza sativa L.), Spectral characteristics, Absorptance, Reflectance, Chlorophyll concentration

附件檔名

華芸線上圖書館

N / A

備註說明

200206-7-4-41-52

Pages:

53-60

論文名稱

「技術短文」非監督性模糊分類最佳類別數之研究

Title

The Validity Measurement of Fuzzy C-means Classifier

作者

陳繼藩, 李志明

Author

Chi-Farn Chen , Jyh-Ming Lee

中文摘要

非監督性模糊分類(FCM: fuzzy c-means)是多光譜衛星影像分類近來經常使用的方法之一。但模糊程度指標(fuzziness index)及最佳類別數的決定,是 FCM 應用於衛星影像通常會碰到的問題。本研究主要是以分類指標 (cluster validity index) 為方法,透過一系列測試,提供使用 FCM 時,模糊程度指標值的應用範圍及最佳類別數的自動化判定。

Abstract

A fundamental problem of the unsupervised classification is often the determination of the valid number of the clusters. This study presents a series of testing procedures to investigate the application of a clustering validity function to the fuzzy c-means (FCM) algorithm. The main objective of the investigation is designed to test the performance of the validity criteria for optimal partition. The testing results from a series of remote sensing images indicate that the validity function indeed can be used as the optimal index for the choice of the cluster numbers for the unsupervised fuzzy c-means classification. Moreover, the tests also provide the proper guide for the determination of the applicable range of the fuzziness index.

關鍵字

非監督性分類、模糊分類、分類指標

Keywords

unsupervised classification fuzzy c-means cluster validity index

附件檔名

華芸線上圖書館

N / A

備註說明

200206-7-4-53-60

Pages:

61-68

論文名稱

「技術短文」應用 EROS 與 SPOT 衛星影像進行高解析自然色影像合成

Title

An Experiment to Color EROS Panchromatic Image

作者

張立雨 , 陳繼藩 , 陳哲俊

Author

L. Y. Chang , C. F. Chen , A. J. Chen

中文摘要

傳統上, RGB 與 IHS或 RGB與 LAB之影像色彩轉換方法,被廣泛的應用於合成高解析全色態影像與低解析多光譜影像,進而產生既是多光譜且高空間解析度之合成影像。但是要進行此種形式之影像合成,其先決條件為影像間的空間解析度差別必須有所限制。若此項條件未能滿足時,則低空間解析度之影像將會產生過度取樣之情形,最後將在所合成的影像上造成色彩邊界特徵模糊化以及銳利度降低之現象。本研究提出以影像分類與聚塊為主之法則,針對前述問題進行方法上之改進。測試結果顯示,本研究所提出之方法針對較低解析度(影像空間解析度 20公尺)之 SPOT多光譜自然色影像以及較高解析度(影像空間解析度 2公尺)之EROS全色態影像進行合成時,在合成的影像中其色彩上之邊界特徵及銳利度較以傳統方法合成之結果為顯著。

Abstract

Traditionally, the color transformation method such as IHS or LAB transformation is usually used as a fusion technique to color higher spatial resolution panchromatic image from lower spatial resolution multi­ spectral image. However the analysis indicates that the success of this image fusion technique depends heavily on a small proportion of spatial resolution between multi-spectral and panchromatic images. For example, a relatively high proportion of spatial resolution will over-resample the image, and consequently smooth down the color variation and feature sharpness of the resultant image. In this study, we develop a segmentation technique to color high spatial resolution panchromatic image. The experiment shows that the proposed approach is able to color EROS panchromatic image (2m resolution) from SPOT multi-spectral composite image (10m resolution) with color and sharpness preserved in the final product.

關鍵字

色彩轉換,非監督性影像分類,影像合成

Keywords

Color Transformation, Unsupervised Classification, Image Fusion

附件檔名

華芸線上圖書館

N / A

備註說明

200206-7-4-60-68

Pages:

69-76

論文名稱

「技術短文」應用 NOAA AVHRR 植被指數分類資料估算台灣地區森林面積之研究

Title

Estimation of Taiwan's Forested Areas by Classified NDVI Maps from NOAA AVHRR Data

作者

劉振榮 , 林唐煌 , 郭宗華

Author

Gin-Rong Liu , Tang-Huang Lin , Tsung-Hua Kuo

中文摘要

本研究之主要目標為應用NOAA AVHRR資料所建立之台灣地區植被指數分布,計算台灣地區森林分布及其所佔面積之比例。由於台灣地區雲出現之頻率頗高,不易獲得晴空的影像資抖,需藉由多張衛星影像合成較為晴空之影像資料。本文之合成影像資料是以月為單位,據以建立台灣地區逐月之植被指數分布圖,除了分析植被指數之變化情形外,並配合地物分布之基本資料建立森林地區之辨別模式,以利森林面積估算之應用。研究結果在 1998年1月份所計算台灣地區森林之分布型態及其所佔面積比例(54.5%),與1995年林務局調查森林的分布型態及面積比例(58.5%)均頗為相近,顯示此一方法之可行性頗高,值得進一步地深入研究。

Abstract

The goal of this study is by applying NOAA AVHRR data in delineating NDVI maps throughout Taiwan, which can be utilized in the surveys of forested areas. Due to the frequent appearance of clouds, the composite NDVI maps were conducted in a monthly basis where the monthly and seasonal variations of the NDVI values around the mountainous areas were analyzed. The result showed that the total forest area assessed by the NDVI value reached 54.5%. This percentage was rather close to the surveys conducted on the surface, which was 58.5%, proving our procedure to be rather practical.

關鍵字

NOAA AVHRR、森林面積、植被指數分布圖

Keywords

NOAA AVHRR, forested area, NDVI map

附件檔名

華芸線上圖書館

N / A

備註說明

200206-7-4-69-76

Pages:

77-87

論文名稱

國際航遙測學會網際網路之過去、現在與未來

Title

ISPRS and Internet: history, presence, and future

作者

陳端墀

Author

Tuan-chih Chen

中文摘要

筆者擔任國際航空測量及遙感探測學會(ISPRS)1996-2000 WG VI/4(網際網路)主席,並繼任2000-2004編輯委員(http://www.isprs.org/structure/editors.html),負責該學會之網際網路及「行事曆」(http://www.isprs.org/calendar.html)事宜,應邀在ISPRS第六委員會期中研討會提出會務報告。本報告對ISPRS網際網路過去之發展做一檢討,對其現況做一統計,對其將來做一規畫,以便在2004年(每四年一次)之會員大會上向總部及103個會員國提出總結報告。本報告承蒙本會補助註冊費,謹此致謝。

Abstract

The author has been chairperson of WG VI/4, International Society for Photogrammetry and Remote Sensing (ISPRS), for 1996-2000, and has been appointed as one of the Editors of ISPRS (http://www.isprs. org/structure/editors.html) for 2000-2004. The author is responsible for Internet of ISPRS and compiling the ISPRS Events Calendar (http://www.isprs.org/calendar.html), which will be published in ISPRS Highlights and placed on the ISPRS home page (http://www.isprs.org). This paper presents the history, presence, and future of the Internet for ISPRS. The Internet and the most known part of it, the World Wide Web, are one of the greatest inventions of our time. The formation and the growth of these big Net has changed the way we do business, communicate, entertain, retrieve information, and even educate ourselves. This worldwide medium allows interaction with people without regard for geographic location and it is a great exchange and source of data, information and software. Inside this electronic world, ISPRS is present since 1994 with the goal of providing information, coordination and operations structure of its activities. In this paper, at first a short history of the WWW is presented, with its main facilities and possibilities. In the second part, after a short introduction on the web site of the society, are presented history, presence, and future plans about the use of Internet by ISPRS, and how ISPRS can make use of existing technologies to improve what it now offered, including the educational strategy. The ISPRS Events Calendar is also introduced.

關鍵字

國際航遙測學會、航空測量、遙感探測、網際網路、網站、資訊、教育、統計

Keywords

ISPRS, photogrammetry, Remote Sensing, Internet, worldwide web, information, education, statistics

附件檔名

華芸線上圖書館

N / A

備註說明

200206-7-4-77-87

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