影像中的文字為重要的感興趣區域(regions of interest)，在影像中定位文字供後續處理能夠幫助該影像相關資訊的擷取，並有利於許多有趣應用的開發。近年來語義分割和通用物件檢測框架技術已被文字偵測任務所廣泛採用，兩者在實作中有各自的優勢與缺點。本研究提出結合兩者優點的文字偵測機制，其中包含一個主要文字串偵測網路輔以一個文字精修網路。主要網路利用語意分割的方式並搭配FPN (Feature Pyramid Network)與ASPP (Atrous Spatial Pyramid Pooling)等技術，強化特徵提取效果，藉此偵測文字區域與邊框，將其視為主要結果且具備高召回率。我們接著使用以區域檢測框架為基礎的精修網路再次分析可能的文字區域，將主要結果中較不確定區域以精修網路協助判斷，最後再使用非極大值抑制技術(Non-Maximum Suppression, NMS)得到最終的文字區域偵測結果。實驗結果顯示本研究能有效的在複雜場景中偵測文字，並藉此探討兩種不同架構的深度學習網路在目標應用中的使用方式。;Texts appearing in images are often regions of interest and locating such areas for further analysis may help to extract image-related information and facilitate many interesting applications. Pixel-based segmentation and region-based object classification are two methodologies for locating text areas in images and have their own pros and cons. In this research, we proposed a text detection scheme consisting a main pixel-based classification network and a supplemented region proposal network. The main network is a Fully Convolutional Network (FCN) employing Feature Pyramid Network (FPN) and Atrous Spatial Pyramid Pooling (ASPP) to identify text areas and borders with higher recall. Certain areas are further processed by the supplemented refinement network, i.e., a simplified Connectionist Text Proposal Network (CTPN) with higher precision. Non-Maximum Suppression (NMS) is then applied to form suitable text-lines. The experimental results show feasibility of the proposed text-detection scheme.
