tag:blogger.com,1999:blog-1840985738235902482.post3361749507924728688..comments2024-03-27T07:14:48.488-04:00Comments on John the Math Guy: Munsell and the deltaEJohn Seymourhttp://www.blogger.com/profile/11350487038873935295noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-1840985738235902482.post-69072911751531826122017-07-18T15:00:55.808-04:002017-07-18T15:00:55.808-04:00Thank you, Roger!
Drop me an email, and I will ge...Thank you, Roger!<br /><br />Drop me an email, and I will get you on my mailing list: <br />john@johnthemathguy.comJohn Seymourhttps://www.blogger.com/profile/11350487038873935295noreply@blogger.comtag:blogger.com,1999:blog-1840985738235902482.post-86592526883409579952017-07-18T14:48:19.964-04:002017-07-18T14:48:19.964-04:00I love following this blog. Thank you, Mr Seymour....I love following this blog. Thank you, Mr Seymour.<br />-<br />Roger BretonAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-1840985738235902482.post-23882995428370591922017-07-17T14:44:57.109-04:002017-07-17T14:44:57.109-04:00I received (via LinkedIn) a correction to this blo...I received (via LinkedIn) a correction to this blog post from Michael Huda:<br /><br />"Hi John, just for clarity, Richard Hunter was the first to develop the De calculation and that was in 1945. It was transferred to CIELab ColorSpace when it was ratified in 1976. Thanks for the interesting article."<br /><br />I made a small correction to Michael's correction:<br /><br />The DE color difference goes back just a bit further than that, Michael.<br /><br />The earliest reference to the DE calculation that I can find is a paper by Deanne Judd of 1939: "Specification of color tolerances at the national bureau of standards". In this paper, he uses the Pythagorean distance formula (same formula as in the 1976 DE calculation) on the UCS color space to derive the "NBS unit of color difference".<br /><br />I have not been able to find a copy of the Judd 1939 paper, but it is described by Richard Hunter in the paper "Photoelectric tristimulus colorimetry with three filters" from the National Bureau of Standards (1942). Hunter provides six different formulas for DE, all of which have some resemblance to the 1976 formula.<br /><br />Judd also provided a description of the NBS formula in "Physiological Optics at the National Bureau of Standards" (1967, Applied Optics). In this paper, he traces the concept of the difference between two colors back to a 1909 paper by Nutting.John Seymourhttps://www.blogger.com/profile/11350487038873935295noreply@blogger.comtag:blogger.com,1999:blog-1840985738235902482.post-92056890663471135312017-07-17T14:42:19.702-04:002017-07-17T14:42:19.702-04:00I received a comment by email from my good buddy, ...I received a comment by email from my good buddy, Robin Myers:<br /><br />I always enjoy your blogs and I was especially interested in reading your latest blog about ∆E and the Munsell system.<br /><br />However, I must correct you on one thing. Although Albert Munsell published “A Color Notation” in 1905, at that time he did not produce a book with actual color chips. The first publication of his “Atlas of The Munsell Color System”, with painted chips, was not published until 1915. This publication had hundreds of color patches, but not thousands. <br /><br />I have measured all 477 surviving patches in my copy (#115). Chart H is missing from my copy, some scurilous miscreant removed it, but from the ghost image of the cover page there were 77 patches on this chart, arranged in 11 columns of 7 patches each. That would bring the total patches originally published to 554.<br /><br />Robin has a data file with measurements of his copy of the Munsell Color System Atlas onine: http://rmimaging.com/spectral_library/library_index.html You will need a copy of SpectraShop to read the file.<br /> John Seymourhttps://www.blogger.com/profile/11350487038873935295noreply@blogger.comtag:blogger.com,1999:blog-1840985738235902482.post-6657007194524135952017-07-12T11:17:33.819-04:002017-07-12T11:17:33.819-04:00Very nice story, love it. The evolution of color f...Very nice story, love it. The evolution of color formulas.Roel Gottenboshttps://www.blogger.com/profile/04545381829822042335noreply@blogger.com