• 期刊

以時空資訊探討百年來台南古都沿海地區的土地利用變遷

時空資訊的紀錄，能幫助我們了解時代變遷之地理現象，自20 世紀以來，台灣開始出現經過精細測量之圖資，包括地形圖及航照影像，然而欲應用時空資訊，必須將其糾正對位到一致的坐標系統上。本研究利用航測軟體(SOCET GXP 4.0)以及六參數轉換進行糾正對位，使用(1)古地圖：1904 年台灣堡圖及1921 年台灣地形圖(2)1947-1948 年及1970 年代歷史航照影像(3)1985-1989 年第一版經建版地形圖(4)2009 年福衛二號衛星影像(5)2010 年正射影像，建立了百年圖資對位處理流程，及對其精度進行評估，其中古地圖及美軍空軍航照之精度大約可達十餘公尺，而1970 年代歷史航照經過空三之正射影像精度可達約2公尺，並以台南古都沿海地區(約今安平一帶)為研究範圍，探討其土地利用的變遷，藉由影像判釋數化九項土地利用類別來量化土地利用變遷資料，以及透過轉移矩陣了解各土地利用如何轉變，並且配合文史資料探討及呈現其土地利用變遷的過程。

• 期刊

Cloud Removal from Satellite Images Using Integrated Information Reconstruction

Cloud covers present in optical satellite images generally limit the data usage and increase the difficulty of data analysis. Information reconstruction of could-contaminated images thus plays a fundamental step in data preprocessing. A method to accurately and consistently reconstruct information of cloud-contaminated pixels in multitemporal remote-sensing images is proposed in this study. By utilizing temporal correlation of multitemporal images, a patch-based information reconstruction that spatiotemporally segments a sequence of images into several patches with similar temporal variation is performed, and then information from cloud-free and high-similarity patches is cloned to their corresponding cloud-contaminated patches. In addition, a seam passing through homogenous regions is determined for a cloud-contaminated region to reduce radiometric inconsistency. A cloud-contaminated region is segmented into several patches and their corresponding cloud-free patches are determined by a quality assessment index, and the multi-patch information cloning is solved by an optimization process with a determined seam. These processes enable the proposed method to accurately and consistently reconstruct missing information in cloud areas. Qualitative analyses on sequences of images acquired by the Landsat-7 ETM+ sensor and a quantitative analysis on a simulated data are conducted to evaluate the proposed method. The experimental results the ability of our method to generate visually smoothing reconstruction results.

• 期刊

A Study on Shadow Detection and Color Restoration in Aerial Images

The intensity value on each image pixel is determined by the functions of incident illumination and reflection of ground objects. In fact, light cast on terrain objects such as buildings and trees would cause shadows and occlusion. It is hard to restore original textures and color information in shadow areas. Many detailed information is hidden or lost due to such problems. Moreover, false color tone, shape distortion and inaccurate image matching within shadow areas also infect image recognition. This paper proposes an algorithm for automatic shadow detection based on the principal component analysis(PCA). It is tested by using both RGB and HSI bands in order to determine a proper and suitable color space for shadow detection. Besides shadow detection, color restoration in shadow areas is an important issue, too. This paper also performs subjective and objective evaluation on both histogram matching method and the local statistics method for color restoration in shadow areas. Test results demonstrate satisfied quality for restored images in shadow area.

• 期刊

無人飛行載具搭載數位相機於地質構造判釋之應用

隨著科技進步，野外地質調查的方法日新月異。結合現代化空間資訊技術的使用，野外資料的取得效率與精度大幅提升。本文將以近石門水庫大漢溪溪床露頭和大甲溪峭壁的三義斷層露頭為例，以無人飛行載具(Unmanned aerial vehicle, UAV)掛載數位相機，結合全球衛星定位系統(Global positioning system, GPS)靜態測量，獲取區域地面控制點坐標，處理所得之正射影像和立面影像，進行地質構造判釋。大漢溪溪床的正射影像中呈現一系列走向N20°E 左移的斷層，及一振幅約90 公尺、半波長約120 公尺的S 形褶皺。980 公尺寬的大甲溪峭壁立面影像中發現三義斷層以至少三條分支的逆斷層帶出現，由西往東分別為斷層F1、 F2 和 F3。F1 切穿現代礫石層，判定為最活躍的斷層；F2 並無切穿上覆約70 公尺的階地堆積層，西側未再出現早於四百萬年形成的桂竹林層青灰色砂岩，研判為具最大錯移量的分支；F3 上盤為為青灰色砂岩組成之桂竹林層，下盤為階地堆積層，近地表為風化層及植被所覆蓋。以上的地質構造判釋，皆得利於UAV 所提供的影像，地面取樣距離(Ground sample distance, GSD)達4cm/pixel；GPS 靜態觀測，經解算與平差後，地面控制點的平面精度達0.5 公分，高程精度約為1 公分內；數值地表模型(Digitalsurface model, DSM)的精度約莫為公分等級，足見UAV 影像測繪搭配高精度地面控制點的高實用性，為未來地質調查不可或缺的工具。

• 期刊

導入專業測繪成果於開放街圖

「開放街圖」OSM(OpenStreetMap)，於2004 年由英國Steve Coast 發起，其為一群眾計劃任何人皆可參與，經由貢獻者主動編輯周遭與家鄉的地圖。然而開放街圖的精度是一值得探討的議題，所以將使用測量專業知識，例如:控制測量、水準測量、GPS 測量等專業技術以提高OSM 精度，使OSM 能夠更加精確。本研究主要是讓專業測量成果融入於OSM，以「台南市台南公園」為例，測量的時間為2014 年7至8 月，並匯入專業測量成果於JOSM 編輯器，進行OSM 編修。透過實際進行編修前後OSM 比對，可瞭解專業測量結果確實豐富了開放街圖，也透過OSM，讓大眾看到測量製圖結果，因此除了內容豐富之外，編修前後建物與水池位置、數量、面積與形狀確實有大幅改變。