Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

[css-color] Converting Between Uncalibrated CMYK and RGB-Based Colors #302

Closed
svgeesus opened this issue Jul 10, 2016 · 2 comments
Closed

[css-color] Converting Between Uncalibrated CMYK and RGB-Based Colors #302

svgeesus opened this issue Jul 10, 2016 · 2 comments
Assignees
@svgeesus
Labels
Closed Accepted as Obvious Bugfix css-color-4 Current Work

Comments

@svgeesus
Copy link
Contributor

https://drafts.csswg.org/css-color/#cmyk-rgb

This section now needs to clearly distinguish between calibrated (icc-based) color on the one hand, and uncalibrated device-cmyk on the other. This particularly affects conversion to and from RGB.

Resolution depends on #301
@svgeesus svgeesus added the css-color-4 Current Work label Jul 10, 2016
@svgeesus svgeesus self-assigned this Jul 10, 2016
@cabanier
Copy link
Member

The PDF reference manual [1] sections 6.2.3 and 6.2.4 define a different conversion based on BlackGeneration and UnderColorRemoval.
Since those seem a bit easier(ie no divisions), maybe we can adopt them

1: www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/pdf_reference_1-7.pdf

@svgeesus
Copy link
Contributor Author

The spec section cited says that BG and UCR are not used:
(sorry for the inaccessible screenshot, the PDF spec disallows copying text!)
cmyk-to-rgb-pdf
However, agree; these simple conversions are commonly cited, they are not specific to PDF; and the spec now uses them.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees

@svgeesus svgeesus

Labels
Closed Accepted as Obvious Bugfix css-color-4 Current Work
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
2 participants
@cabanier @svgeesus