I been measuring flowers with one of my colorimeter. The petals of one such flower, lit by noon direct sunlight, gave me the following CIE xyY 1931/2 coordinates: CIE x = 0.3058 CIE y = 0.2053 CIE Y = 846 cd/m2 I took a picture of the flower and would like to use these coordinates as a guide for color correction. My question is how do I convert xyY to Photoshop's Lab? Not an easy problem, I know, that's why I turn to you guys for any help. Best / Roger
http://www.brucelindbloom.com/ STEVE MILLER Color Management Specialist BIC Graphic North America / 1000 3rd Ave. SW, Sleepy Eye, MN 56085 Tel: (1) 507 794 8203 Email: steve.miller@bicgraphic.com www.bicgraphic.com / www.norwood.com CONFIDENTIALITY NOTICE This electronic message is confidential and may contain legally privileged information intended only for the use of the individual or company named above. If the reader of this message is not the intended recipient, or the employee or agent responsible to deliver it to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communications is strictly prohibited. If you have received this communication in error please immediately notify us by telephone and return the original message to us at the address above. On 01/08/2017 5:05, "Roger Breton" <graxx@videotron.ca> wrote:
I been measuring flowers with one of my colorimeter.
The petals of one such flower, lit by noon direct sunlight, gave me the following CIE xyY 1931/2 coordinates:
CIE x = 0.3058
CIE y = 0.2053
CIE Y = 846 cd/m2
I took a picture of the flower and would like to use these coordinates as a guide for color correction.
My question is how do I convert xyY to Photoshop's Lab?
Not an easy problem, I know, that's why I turn to you guys for any help.
Best / Roger
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Roger, You need to measure a reference white under the same conditions. You will get Y (absolute value in cd/m2) for white, which you can use to normalize data with Y of White Point equal to 100. Knowing the WP will also enable you to convert from the measurement WP to a standard WP (D50, etc.) Danny www.babelcolor.com -----Message d'origine----- De : Colorsync-users [mailto:colorsync-users-bounces+dpascale=babelcolor.com@lists.apple.com] De la part de Roger Breton Envoyé : 1 août 2017 18:06 À : 'ColorSync' Objet : Convert CIE xyY to Photoshop D50/2 CIE Lab I been measuring flowers with one of my colorimeter. The petals of one such flower, lit by noon direct sunlight, gave me the following CIE xyY 1931/2 coordinates: CIE x = 0.3058 CIE y = 0.2053 CIE Y = 846 cd/m2 I took a picture of the flower and would like to use these coordinates as a guide for color correction. My question is how do I convert xyY to Photoshop's Lab? Not an easy problem, I know, that's why I turn to you guys for any help. Best / Roger
participants (3)
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dpascale
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Miller, Steve
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Roger Breton