こんにちは TAG-さん!

The Color on the Web CG is kindly requesting a TAG review of its proposed modification to the Web Platform to support High Dynamic Range (HDR) imagery in HTML Canvas.

The complete proposal is at https://github.com/w3c/ColorWeb-CG/blob/hdr_canvas_r2/hdr_html_canvas_element.md

Today HTML Canvas supports only 8 bit per color channel and two PredefinedColorSpace color spaces (srgb and display-p3). This is insufficient for High-Dynamic Range (HDR) imagery, which is in widespread use today. Accordingly, the following API modifications are needed to manipulate HDR images in HTML Canvas:

• add BT.2100 color spaces to PredefinedColorSpace
• add higher bit depth capabilities to CanvasRenderingContext2DSettings
• add higher bit depth capabilities to ImageDataSettings
• add image color volume information to ImageDataSettings and CanvasRenderingContext2DSettings
• add display color volume information to the Screen interface of the CSS Object Model, to determine the characteristics of the display on which the image is being reproduced

Please note that the proposed screenColorInfo property adds a fingerprinting surface. This feature is however intended primarily for advanced color volume mapping applications and is not believed to be generally necessary.

Contacts: @palemieux and @svgeesus (Color on the Web CG co-chairs)

Feedback, issues and questions are welcome at mailto:public-colorweb@w3.org and https://github.com/w3c/ColorWeb-CG/issues.