彩色數位全像術及其色彩校正之研究

Abstract

本論文主要探討彩色數位全像術(color digital holography)及其重建影像的色彩偏移修正，以達到重建真實彩色影像的目的。因彩色數位全像術有別於傳統彩色照相術，是透過兩道光波的疊加干涉來記錄資訊，因此本論文旨在修正彩色數位全像的記錄過程中所產生的色差(color difference, ΔE)。本研究工作主要是使用色彩校正的演算法來完成色彩偏移的修正，而色彩校正的方式包含色調(tone correction)與色度校正(chromaticity correction)兩個程序。首先利用遞迴演算的方式計算色調的多項式回歸(poly nominal regression)方程式，接著再針對色彩偏移的部分求出重建與標準影像之間的轉換矩陣，最後再將色調與色度校正的方程式，輸出為彩色數位全像系統的色彩校正描述檔(color profile)。內文中敘述色彩校正的演算方式，並用電腦模擬來證實色彩校正的可行性，最後實際應用於光學實驗以驗證之。

This work investigates the color difference during the optical recording and numerical reconstruction procedure, and proposes a color correction algorithm to perform color reproduction in color digital holography system. Owing to color digital holography is different to traditional color photography, the optical interference are employed to record the amplitude and phase information of the object in the digital holographic process. The color correction algorithm consists of two parts: first, the tone correction that can be used to find the optimal poly nominal regression function by iteratrive procedures; second, the chromaticity correction that can generate a transformation matrix between standard image and reconstructed image for compensating color difference. As a result, the tone and chromaticity correction are used to produce a general-purpose color profile in the color digital holography system for different objects. In this study, we invesigate the color correction method, computer simulation of the color correction algorithm and related optical experiments to verified the system performance.