Abstract
衛星通訊在Ka band上因為雨滴的衰減變得非常容易損耗,兩層式的編 碼方式可以使用在這樣的環境來解決問題。而空間解析度的延伸性是其中 的一種分層方式並且傳送不同保護程度的資料，這個方法的實現是將視訊 資料分成兩部份，具有較低空間解析度的基礎層被視為是重要的資訊而且 必須正確地從解碼端被解回。假設收到增強層中受損耗的資料，解碼端不 僅要有能力去使用基礎層的資訊來補償損失；而且還能結合這兩層的資訊 產生一種較高品質的影像。在我們的論文裡頭，我們將非延伸性的編碼結 構擴展到空間解析度可延伸的結構來實現我們的兩層編碼。這兩層之間的 加權方式將是我們研究的重點，實驗的結果證明了我們所提出的方法能夠 成功地逼近或超越單層式的編碼表現。在可預見的未來，有高保護能力且 表現出色的空間解析度延伸性編碼將會大量地被使用。除此之外，空間解 析度的延伸在多媒體通訊領域中扮演了重要的角色，我們最後將應用我們 的空間解析度延伸方式來實現多媒體的世界。 Satellite communication through Ka band is very lossy due to rain attenuation. To solve this problem, two-layer coding schemes can be employed in this environment. Spatial scalability is one of them that transmit video data with different level of protection. The implementation of this scheme is to partition the video data into two portions. The base layer which has low spatial resolution will be regarded as the critical information and needs to be correctly received by decoder. If the partly corrupted information of enhancement layer is received, the decoder has not only the ability to conceal the degraded part of enhancement layer by using its base-layer information but can combine these two layers to reproduce high quality pictures. In our thesis, we implement the spatial scalability by expanding the nonscalable structure into its spatial-profile structure. The weighting method of these two layers is the key point of our study. It can be shown that our proposed spatial scalability will successfully approximate nonscalable performance or even outperform that. In the future, we may expect that high protection capability with better performance of spatial scalability will be employed extensively. Besides, spatial scalability also plays an important role in multimedia communication. We will finally apply our spatial scalable scheme into multimedia world.