撮像装置におけるメタリック塗装の質感取得方法に関する研究

摘要

メタリック塗装の撮影画像を見ると実物とは異なった印象を受ける．それは撮影する際の重要な問題の一つである，ダイナミックレンジ（DR）の不足による信号値の飽和が原因として考えられる．本研究では，メタリック塗装の質感取得を実現することを目的とし，塗装質感の中の深み感に着目した．メタリック塗装中の光輝材における信号値の飽和がないように，広DR画像を作成し，光輝材の見え方に関する主観評価実験を実施した．その結果，DRを広げることで実物に近い色情報の取得が可能となり，特に光輝材の面積による輝度差を大きくすることで，より光輝材の見え方は実物に近づくという結果が得られた．%When we see photographic images of metallic topcoats, we often perceive that the impression of them is different from those of real objects. It probably seems that the phenomenon is caused by saturation of image signals resulting from lacks of the dynamic range. This is essential for high fidelity video cameras. The objective of the research is to make clear a way of acquisition of texture information of metallic topcoats. For our first approach, we tried to analyze depth feeling for metallic topcoats. In order not to saturate image signals of flake pigments in the coating, high dynamic range images were made. We subjectively evaluated the appearance of flake pigments in the images by comparing with that of real objects of metallic topcoats. As the result, the appearance of flake pigments in the images become close to that of real objects when colors of images were almost equal to them and luminance of the flakes are proportional to their sizes with higher ratio.