To relate human color perception to the physical color stimulus, the CIE developed a color space in 1931 based on a coordinate system. This system was called the Yxy color space or the Tristimulus color space. The system was based on measurement values relative to an averaged observer with a 2\u00b0 field of view aligned to the main viewing direction. Since the human field of view is larger, a second field of view with 10\u00b0 was developed in 1964. The values X, Y, and Z are the primary values in this system, with which any color can be defined. Therefore, the system is often referred to as the Tristimulus System.
\nFrom the three color values X, Y and Z of the tristimulus system, all other color values such as L*, a* b* and many color indices can be calculated.
Historically, color was first measured with Tristimulus colorimeters. In this method, the sample is illuminated with white light, and the reflected or transmitted light is measured through red, green, and blue color filters. The intensity of the light measured through these color filters is reported as the X, Y, and Z values. Each hue is uniquely defined by these three values (Tristimulus). The consideration of light source and standard observer is defined by the color filters used.
Later, spectrophotometers were developed to measure the entire reflection or transmission spectrum of a sample. By multiplying this spectrum with the spectral curve of the light source and the functions of the standard observer, the corresponding X, Y, and Z values are obtained after integration.
\nWhile these Tristimulus values uniquely define each color, they are not intuitive for use. Therefore, calculations for various L*, a*, b* systems were developed later to make color representation more practical. <\/p>\n","protected":false},"excerpt":{"rendered":"
To relate human color perception to the physical color stimulus, the CIE developed a color space in 1931 based on a coordinate system. This system was called the Yxy color space or the Tristimulus color space. The system was based on measurement values relative to an averaged observer with a 2\u00b0 field of view aligned […]<\/p>\n","protected":false},"author":1,"featured_media":0,"menu_order":0,"template":"","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"glossary-categories":[1352],"glossary-tags":[],"glossary-languages":[],"class_list":["post-378205","glossary","type-glossary","status-publish","hentry","glossary-categories-colorimetry"],"post_title":"CIE Tristimulus System","post_content":"To relate human color perception to the physical color stimulus, the CIE developed a color space in 1931 based on a coordinate system. This system was called the Yxy color space or the Tristimulus color space. The system was based on measurement values relative to an averaged observer with a 2\u00b0 field of view aligned to the main viewing direction. Since the human field of view is larger, a second field of view with 10\u00b0 was developed in 1964. The values X, Y, and Z are the primary values in this system, with which any color can be defined. Therefore, the system is often referred to as the Tristimulus System.\nFrom the three color values X, Y and Z of the tristimulus system, all other color values such as L*, a* b* and many color indices can be calculated.
Historically, color was first measured with Tristimulus colorimeters. In this method, the sample is illuminated with white light, and the reflected or transmitted light is measured through red, green, and blue color filters. The intensity of the light measured through these color filters is reported as the X, Y, and Z values. Each hue is uniquely defined by these three values (Tristimulus). The consideration of light source and standard observer is defined by the color filters used.
Later, spectrophotometers were developed to measure the entire reflection or transmission spectrum of a sample. By multiplying this spectrum with the spectral curve of the light source and the functions of the standard observer, the corresponding X, Y, and Z values are obtained after integration. \nWhile these Tristimulus values uniquely define each color, they are not intuitive for use. Therefore, calculations for various L*, a*, b* systems were developed later to make color representation more practical. \n","_links":{"self":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/glossary\/378205","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/glossary"}],"about":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/types\/glossary"}],"author":[{"embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":0,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/glossary\/378205\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/media?parent=378205"}],"wp:term":[{"taxonomy":"glossary-categories","embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/glossary-categories?post=378205"},{"taxonomy":"glossary-tags","embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/glossary-tags?post=378205"},{"taxonomy":"glossary-languages","embeddable":true,"href":"https:\/\/www.hunterlab.eu\/en\/wp-json\/wp\/v2\/glossary-languages?post=378205"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}