高解析(640x480)短波紅外線影像擷取系統之設計與實現

Abstract

近年來短波紅外線(Short Wave Infrared；SWIR，波長介於900nm~1700nm)影像已廣泛的應用到各個領域，例如：軍事、半導體檢測和飛航安全等，具有相當發展潛力。然而，由於特殊因素使台灣無法取得高解析(640x480)短波紅外線感測模組，限制其於軍事與民生應用的發展。有鑑於此，本論文提出短波紅外線影像擷取系統之設計與實現，內容包含焦平面感測器(Focal Plane Array ; FPA)訊號的數位化與擷取、同步動態隨機存取記憶體(Synchronous Dynamic Random Access Memory; SDRAM)控制器設計以及影像訊號即時輸出。研究中運用中華電信研究所之焦平面陣列感測模組，以實現即時(Frame Rate = 30)影像擷取系統為目標。本研究的進行可以劃分為三個階段：(1)硬體IC的選擇：根據焦平面感測器的規格選擇系統所需要的其他IC，如系統核心之中央處理器、高速類比數位轉換器、動態隨機存取記憶體與影像訊號編碼器等。(2)硬體描述語言之程式設計：使用FPGA同步控制系統各部硬體使系統正常運作。(3)系統製作：系統將實現於PCB上使其成為獨立系統，並設計本模組所對應的鏡頭機構。完成之短波紅外線影像擷取系統可輸出NTSC規格之影像訊號，由NTSC顯示器、平面顯示器(需附有類比影像訊號輸入端子)與CRT顯示器等，均可顯示擷取之短波紅外線影像。

The short wave infrared (SWIR- with wavelength about 900nm to 1700nm) image has been applied in many applications such as military, semiconductor inspection and aviation security. For some reasons, Taiwan cannot acquire high resolution (640x480) SWIR systems, which make impossible the usage of the SWIR image detection in military and civilian applications. To remedy the problem, this thesis intends to design and realize a high-resolution SWIR image acquisition system, including digitization and acquisition of focal plane array (FPA) signals, design of SDRAM controller and real-time image signal transformation and display. This system is equipped with the FPA provided by a Taiwanese manufacture - Chunghwa Telecom Co., Ltd. The work is divided into three parts --- 1.Selection of hardware ICs according to specification for FPA. 2. Design of timing generator for the image acquisition system to control FPA and other ICs by Verilog HDL programming. 3. Integrate the independent system on a PCB. Finished camera outputs SWIR image signal in NTSC format, which can be displayed on NTSC monitor, flat panel display with an AV input terminal and CRT display instantaneously in speed of frame rate = 30.