數位機頂盒的影像品質研究：維持品質指標下改進測試生產力

Abstract

在數位家庭與多媒體產品中，數位機頂盒扮演著極為重要的溝通橋樑，其中讓使用者能直接感受到產品性能優劣的第一印象，莫過於影像與聲音的品質。然而一般影像測試時，需要使用各種不同的測試圖形，所以我們依據影像品質指標，提出一種組合式圖形測試方法：把二十四種個別單一的圖形，構成一種組合式圖形。另外，在數位機頂盒系統品質測試中，需要測試影音訊號輸出品質、數位壓縮的相容性與傳輸網路所造成的影響，若要全部測試則高達329,726,592項，故我們使用一台電腦控制了影音訊號源、數位壓縮設備、傳輸網路、影像聲音品質分析儀，實作了自動化測試系統，此一系統可以大大地縮短測試時間。綜觀上述之研究其優點：降低測試複雜性、縮短測試週期、提高產品競爭力進而大幅提升測試生產力。

Among many multimedia products, digital set-top box plays a key role as consumer promise equipment. The key performance index for a set-top box appears to be its video and audio quality. The video quality is benchmarked by many different types of video patterns. In this thesis, we propose a Video Combination Technique (VCT) to integrate twenty-four video sources into a single one. Thus, the benefits of VCT include lower test complexity, lower test cycles and cost saving. From the system quality point of view, there are testing network transmission layer, compression layer and video/audio output signal layer. All the tests are sum up to be 329,726,592 items. Therefore, we implement an automated test measurement system (ATMS) to save the test cycles and time. So set-top box manufacturing cost is lower and productivity is improved.