粉蠟筆繪圖風格模擬中大面積背景顏色淡化表現相關處理

Abstract

本論文就粉蠟筆繪畫模擬處理過程中所面臨的兩個問題提出解決方案，並予實驗觀察。 (一) 將色彩空間之彩色分佈加以量化(quantization)乃模擬處理過程中必要手段。然此舉常於影像中眼睛看似有相近顏色的大面積區域(通常為天空、牆面或空曠地等背景)造成問題：看似顏色相同的大片區域經顏色量化後往往分屬二個(或以上)不同顏色的區塊，使得最後的繪圖結果顯得相當突兀。 (二) 大面積背景區域在繪畫實務中常被淡化處理：以較粗疏的筆觸及較清淡的色調輕描淡寫地帶過。 論文所提解決方案業經實作於繪畫模擬系統中，並經ㄧ系列影像測試。經與實驗室既有粉蠟筆繪畫模擬系統比較，初步結果令人滿意。

In this thesis, resolutions for the complications encountered by the oil pastel drawing system extant in the lab are proposed. The two complications are described below (1) The process of color space quantization is indispensable in color drawing simulation, not without undesirable side effects however. One of which was the division of a large area of seemingly same color in the image into two or more regions of different quantized colors, thus leading to extremely awkward visual sensation in the final drawing simulation output. (2) In practical oil pastel drawing, the large “background” area in the scene is usually rendered in a more or less compromised fashion in order to make the subject conspicuous. Pragmatically, this is done by using broaden and sparser drawing strokes with depleted color.

The resolutions have been embedded in a new oil pastel drawing simulation system and tested by more than one hundred images of various contents. Compared to the results of the old system, the two complications are found to be resolved with visual satisfaction.