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- 元木 昭寿
- リオデジャネイロ州立大学岩石鉱物学科
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- VARGAS Thais
- Departamento de Mineralogia e Petrologia Ignea, Universidade do Estado do Rio de Janeiro (DMPI/FGEL/CTC/UERJ)
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- NEVES José Luíz Peixoto
- Departamento de Mineralogia e Petrologia Ignea, Universidade do Estado do Rio de Janeiro (DMPI/FGEL/CTC/UERJ)
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- ZUCCO Lóris Lodir
- Colégio Técnico da Universidade Federal Rual do Rio de Janeiro (CTUR/UFRRJ)
書誌事項
- タイトル別名
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- Quantitative analysis of rock and mineral surface color for ornamental and semi-ornamental rocks using image scanner
- イメージスキャナー ニ ヨル ソウショク セキザイ ジュンソウショク セキザイ ノ ゼン ガン オヨビ コウブツ ヒョウメン ハンシャショク ノ テイリョウ ソクテイホウ
この論文をさがす
抄録
This paper describes a method of quantitative reflection color analysis for minerals and whole rock using an image scanner and a general use personal computer. The scanner obtains true color (24 bits) digital images of polished rock surfaces. The software, Wilber, that has been developed for the present project, analyzes the color bitmap information of the area indicated manually by the operator and calculates mean value and standard deviation of RGB, HSB, XYZ, and x-y parameters.<br> Mineral and whole rock colors are generally weak (low saturation) and highly heterogeneous (high hue dispersion) in comparison with artificial objects, animals, and plants. This makes rock color measurement technically difficult, especially in the case of coarse-grained plutonic and metamorphic rocks. To solve the problem, hundreds of trial-and-error experiments have been performed, arriving at the following recommendations.<br> The best optical resolution of the scanner for mineral color and whole rock color analyses is, respectively, 150 dpi (dot per inch) and 75 dpi. The x-y chromaticity diagram, H-S circular diagram, H parameter, and S parameter are convenient to express the measured mineral colors. The RGB color system is not recommended for this use because of strong random reflection effects.<br> By means of S parameter (saturation) of whole rock color, ornamental and semi-ornamental rocks are classified into high-color (S>10.0), middle-color (8.0<S<10.0), low-color (6.0<S<8.0), slight-color (4.0<S<6.0), and grayscale (S<4.0) groups. B parameter (brightness) is efficient for quantitative color evaluation of the grayscale rocks. Using this parameter, they can be subdivided into black (B<25), dark gray (25<B<55), light gray (55<B<85), and white (B>85) groups. The standard deviation of B parameter may represent color hardness for gray granitic rocks. For evaluation of the high-, middle-, and low-color rocks, the H parameter (hue) is recommended. They can be classified into red (0°<H<20°), orange (20°<H<40°), and yellow groups (40°<H<60°). Sodalite syenite and charnockite are classified to be grayscale rocks due to their low color saturation. However, it is recommended that they are exceptionally evaluated by S parameter, or color intensity, because the market price is highly related to their color.
収録刊行物
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- 岩石鉱物科学
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岩石鉱物科学 32 (1), 12-22, 2003
一般社団法人 日本鉱物科学会
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詳細情報 詳細情報について
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- CRID
- 1390001206526279296
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- NII論文ID
- 130000253641
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- NII書誌ID
- AA1146088X
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- COI
- 1:CAS:528:DC%2BD3sXjvVSjsb4%3D
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- ISSN
- 13497979
- 1345630X
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- NDL書誌ID
- 6558461
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- 本文言語コード
- ja
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- データソース種別
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- JaLC
- NDL
- Crossref
- CiNii Articles
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- 抄録ライセンスフラグ
- 使用不可