本研究提出結合固定式攝影機，與可左右轉動(Pan)、上下傾斜(Tilt)與縮放(Zoom)的PTZ攝影機之視訊監控機制。經由分析固定式攝影機所拍攝之畫面，偵測畫面中移動物體並加以追蹤，再控制PTZ攝影機取得目標物較高解析度的影像，並將此細節影像經由資訊隱藏技術隱藏至固定式攝影機所記錄之影片中。本論文主要分為三個部分：第一部分為移動目標偵測，我們首先建立固定式攝影機畫面的背景資訊，以此找出可能的移動物體，並持續追蹤每個移動物體。第二部分為PTZ攝影機控制模組，將固定式攝影機取得之目標資訊轉換成對應參數以自動控制PTZ攝影機，並利用人臉偵測技術擷取目標的細部影像。第三部分為資訊隱藏，將記錄下來的細部影像以及與此目標相關的標籤嵌入至影片中，事後若要查詢資料時，即可利用此標籤取得特定目標相對應的細部影像。實驗結果顯示此系統能有效控制PTZ攝影機去追蹤特定目標，並取得足夠解析度之目標物影像。利用資訊隱藏技術，除了擁有一種新穎的影像查詢機制外，還能夠減少所需儲存的檔案數目，甚至減少檔案儲存所需空間。In this thesis, we propose a framework consisting of two cameras. One static camera is used to detect and track the objects, and one Pan-Tilt-Zoom (PTZ) camera is used to control/collect high-resolution images. In addition, the information hiding technique is exploited to simplify the querying process of examining high resolution images corresponding to objects appearing in videos. The proposed scheme is composed of three main components. The first part is a moving object detection model, in which the moving objects will be collected from the static camera and be tracked continuously. The second part utilizes the position and size information derived in the part one to control the PTZ camera. The face detection module is adopted here to recognize and preserve the region of interesting (ROI) images with suitable resolution from the PTZ camera. The third part is an information hiding scheme. Those ROI images acquired from the PTZ camera and its related labels are embedded into the corresponding video frames. The authorized user can query these ROI images from the video. Experimental results demonstrate that the proposed scheme can detect moving objects, track them simultaneously, and capture the high resolution ROI images at about 25 fps (Frame per Second). The information hiding technique offers not only a simplified querying method but also reduces the number of files that need to be stored.
