- 學位論文
使用兩階段全域映射之高動態範圍色調映射技術之研究
An Approach to Global Tone Mapping of High Dynamic Range Image by Two Pass Mappings
摘要
隨著資訊科技的日新月異，高動態範圍影像(High Dynamic Range Images; HDRI)已經漸漸的被廣泛討論與使用。高動態範圍影像可以完美的記錄自然景像，但卻無法在現有的顯示裝置中呈現，因為目前的顯示裝置只能顯示低動態範圍的影像，所以必須要透過色調映射(Tone Mapping)的方式，將高動態影像範圍壓縮才能顯示。 色調映射的方法已經頻繁的使用在日常生活中，也被認為是一種非常實用的技術。色調映射基本上可分為兩大類：區域色調映射及全域色調映射。全域色調映射的優點就是簡單、速度快，可應用於即時裝置上。因此本論文的主要目的就是提出一個優質與良好的全域色調映射技術，本研究將利用兩次映射的方法來完成高動態影像之色調映射，第一次映射是為了找出映射不均的地方，並做適當的調整。在調整後就進行第二次映射，這可使得每一映射值都包含許多的像素，如此就可讓影像呈現的更完美。
並列摘要
With advances in information technology, high dynamic range images (HDRI) have been discussed and used widely. High dynamic range images can perfectly record natural scene, but it can’t be rendered in conventional display devices with the ability to show low dynamic range images. Therefore, it is necessary to map high dynamic range images into low dynamic range images by the technologies of tone mapping. Tone mapping methods have been frequently used in daily life and are also considered very practical technologies. Tone mapping can basically be divided into two categories: local tone mapping and global tone mapping. The advantages of global tone mapping are simple and fast. It can be applied to real-time devices. Therefore, the main purpose of this paper is to propose a high-quality and good global tone mapping technology. This study will use two pass mappings to complete the tone mapping of high dynamic range image. The first mapping is to find out unsmooth places of mapping, and an adjustment is carried out. After that adjustment, the second mapping can make each mapped values containing a number of pixels. Consequently, the mapped images can be rendered with more details.