即時產生之環車Perspective Top-View影像與其應用：自動停車系統

Abstract

行車安全隨著時代的進步愈來愈受到人們的重視，各大車廠及汽車周邊配備廠商也注意到此一現象，紛紛研發各種車輛駕駛輔助系統，旨在提升行車駕駛者的舒適、效率與安全。而車輛四周的視線死角(Blind areas)一直是威脅行車安全的主因之一。目前已經有一些廠商針對此問題推出相關的產品，他們在車輛四周裝設攝影機，建立環車鳥瞰影像(Aerial images)，藉此影像便可消除視線死角，提升行車安全。但這些產品還依然存在著一些缺陷，本研究分析傳統鳥瞰影像建立過程之缺失並提出新的鳥瞰影像建立流程：Perspective Top-View(PTV) transformation，利用PTV transformation與色彩混合(Color blending)我們建立了品質較好的環車全景俯視影像(PTV images)。除此之外，本研究還進一步利用此影像建立一套可自動偵測環境中停車格並自動停車的車駕輔助系統(AP system)。 另外，為了達到能即時轉換PTV images之目的，我們將Perspective Top-View transformation過程中影像像素之對應關係整合成一轉換表，如此便可用查表法(Look-up table)加速PTV images的建立，達到即時轉換的效果。當有了PTV images之後，使用者便可啟動停車格偵測的程序，此程序找出PTV images中可能的停車格位置供使用者選擇，接著本研究再根據台灣現有的三種標準停車格(路邊停車格、直角停車格、斜角停車格)，分別設計停車的策略，使得車輛可以正確地停入使用者選擇的停車格。 總的來說，本實驗達成了以下目的: 1.可即時產生監控車周的俯視影像 2.可自動偵測俯視影像中可能之停車格位置並可以將車輛正確地停入停車格。With the progress of traffic safety increasing attention has been paid, the major depot and automotive peripherals manufacturers also noticed this phenomenon. They have developed a variety of vehicle driving assistance system for enhancing comfort, efficiency and safety when driving. And the blind areas around the vehicle have been one of the main threats to traffic safety.There are already some manufacturers introduced related products for this problem. They install cameras around the vehicle and build an aerial image. It can eliminate blind areas around the vehicle to improve traffic safety. However, these products still have some defects. This study analyzed the lack of conventional aerial image and proposed a new aerial image building process: Perspective Top-View (PTV) transformation. By PTV transformation and color blending, we had established a better quality aerial image (PTV images). In addition, this study further exploited this image to establish a driving assist system(AP system) which can detect parking space around vehicle and parking automatically.