以iccMAX色彩管理技術優化濾鏡式多頻譜相機之色彩精確度

Optimizing the color accuracy of a filter-based multispectral camera using iccMax profiles

洪維君(Wei-Chun Hung) ； 孫沛立(Pei-Li Sun)

《中華印刷科技年報》 2018 (2018/04) Pp. 371-385

摘要

為了保存與精準複製原來的色彩，近年來各國運用多頻譜影像擷取技術於影像數位典藏領域，使色彩精確再現。ICC提出了一種色彩管理新技術，命名為iccMAX，是個強大和多用途的色彩管理工具。iccMAX描述檔可以作為轉譯影像編碼色彩資訊到色度式描述檔連結空間，可隨意選用光源和觀測者條件，也可以轉譯到頻譜式的描述檔連結空間（spectral PCS），或者到材質式的描述檔連結空間（MCS），在材質通道數量上可靈活地使用或者可以使用命名法的通道編碼。本研究目的是以發展一個優良的多頻譜影像擷取模型，以iccMAX描述檔方式優化濾鏡式多頻譜相機頻譜色彩準確度。本研究以iccMAX架構從相機設備空間轉換到頻譜式的描述檔連結空間（camera-to-spectral PCS）得到優化後的頻譜值，另外，相機色彩空間透過PCC轉到sRGB色彩空間（Camera-via-PCC-to-sRGB），評估兩者轉換模式的結果。也測式了iccMAX提出late-binding的處理功能，應用4種不同光源條件下的多頻譜影像在虛擬的sRGB螢幕顯示其色外貌，評估色彩再現的能力。本研究對於多頻譜數位影像典藏領域，應用新一代ICC色彩管理系統提供了具體可行的方案，有助於實現多頻譜印刷（Multispectral Printing）技術發展。

關鍵字

數位典藏技術 ； 多頻譜影像擷取 ； 色彩管理 ； iccMAX描述檔

並列摘要

In order to protect and reproduce color of cultural relics more accurately, multispectral imaging technology have been introduced to digital image archiving around the world recently. ICC is currently working on iccMAX, a next-generation colour management system which is more versatile. Profiles can be defined to convert encoded image data to a colorimetric PCS with any illuminant and observer, to a spectral PCS, or to a Material Connection Space (MCS) with flexibility in the number and meaning of channels. The study aims to develop a good image acquiring model for a commercial multispectral camera. The captured spectral images were processed by iccMAX to optimize the color accuracy. The spectral and color accuracy of camera-to-spectralPCS (i.e., spectral profile connection space) and camera-to-sRGB conversions were estimated and the resulted errors are acceptable. iccMAX late-binding processing elements also were tested to apply 4 different illuminants to a spectral image to simulate its color appearance on a virtual sRGB display. The color accuracy of the late-binding processing was estimated. It is intended to offer these results as a benchmark reference to iccMAX profile performance for spectral imaging on digital archives and multispectral printing.

並列關鍵字

digital archiving ； multispectral imaging ； colour management ； iccMax Profiles

參考文獻

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