Re: HTML Canvas - Transforms for HDR and WCG

Enclosed is a set of images in various color spaces, including HDR, with ICC profiles.

They all look the same in today’s browsers (tested Safari, Chrome, Firefox)

 

These images can be used for validating Chris Cameron’s concepts.

Color matching without ICC profiles will require display-referred conversions for HLG.

Please try.

 

Lars

 

From: Lars Borg <borg@adobe.com>
Date: Thursday, April 1, 2021 at 11:52 AM
To: Christopher Cameron <ccameron@google.com>, Simon Thompson <Simon.Thompson2@bbc.co.uk>
Cc: "public-colorweb@w3.org" <public-colorweb@w3.org>
Subject: Re: HTML Canvas - Transforms for HDR and WCG
Resent-From: <public-colorweb@w3.org>
Resent-Date: Thu, 01 Apr 2021 21:51:37 +0000

 

If you are doing an image browser for arbitrary images and thus arbitrary color spaces it would be awkward to have to locate a proper image-specific color transform. 

Can’t we just use the info that comes with the image?

If blending with text “Buy Now” the blending should be in the same color space for all images, or else we would need unique text color values for each image.

 

Lars

 

From: Christopher Cameron <ccameron@google.com>
Date: Thursday, April 1, 2021 at 8:13 AM
To: Simon Thompson <Simon.Thompson2@bbc.co.uk>
Cc: Lars Borg <borg@adobe.com>, "public-colorweb@w3.org" <public-colorweb@w3.org>
Subject: Re: HTML Canvas - Transforms for HDR and WCG

 

 

 

On Thu, Apr 1, 2021 at 3:35 AM Simon Thompson-NM <Simon.Thompson2@bbc.co.uk> wrote:

Hi,

 

One further thought from me, the proposal last night depended on using a certain image import function which allowed the user to dictate a target colour space and transform set.  Does a similar video import function exist?

 

Yes! It's the same function, createImageBitmap, and it takes as input: images, SVG, video, canvas (so you can draw your canvas into your canvas), and blob (not-yet-decoded image). The options include a "colorSpaceConversion" option, which is currently "none" or "default". This is where I think we should consider adding a well-defined perceptual colorimetric intent (and this intent wouldn't be path-independent).

 

When the input is a blob (a not-yet-decoded image), the color space conversion can happen simultaneously with image decode.