[Bug]: Image captured on light mode sites composited to black background - unreadable

[renambot]

Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a bug report that matches the one I want to file, without success.

Electron Version

25.x

What operating system are you using?

macOS

Operating System Version

macOS Ventura 13.5

What arch are you using?

arm64 (including Apple Silicon)

Last Known Working Electron version

No response

Expected Behavior

Captured images through contents.beginFrameSubscription returns a ARGB NativeImage I believe, when converted to JPEG (.toJPEG(quality)) should be flatten on a white background or configurable color.

Actual Behavior

Captured images through contents.beginFrameSubscription returns a ARGB NativeImage I believe, when converted to JPEG (.toJPEG(quality)) is flatten on a black background, which makes it unreadable.

This happens on 'light mode' sites like the Electron docs and many others:

• https://www.electronjs.org/docs/latest/api/web-contents

Testcase Gist URL

No response

Additional Information

No response

[github-actions]

Hello @renambot. Thanks for reporting this and helping to make Electron better!

Would it be possible for you to make a standalone testcase with only the code necessary to reproduce the issue? For example, Electron Fiddle is a great tool for making small test cases and makes it easy to publish your test case to a gist that Electron maintainers can use.

Stand-alone test cases make fixing issues go more smoothly: it ensure everyone's looking at the same issue, it removes all unnecessary variables from the equation, and it can also provide the basis for automated regression tests.

Now adding the blocked/need-repro label for this reason. After you make a test case, please link to it in a followup comment. This issue will be closed in 10 days if the above is not addressed.

[renambot]

Here's an electron fiddle test case:

https://gist.github.com/renambot/a1e6ec4e81bcb2e50f15d92948dba8ff

[renambot]

Still there on Electron v26.0.0 on macOS

[renambot]

Still there on Electron v27.0.0 on macOS

[electron-issue-triage]

This issue has been automatically marked as stale. If this issue is still affecting you, please leave any comment (for example, "bump"), and we'll keep it open. If you have any new additional information—in particular, if this is still reproducible in the latest version of Electron or in the beta—please include it with your comment!

[renambot]

Still there on 28.1.3 macOS

[electron-issue-triage]

This issue has been automatically marked as stale. If this issue is still affecting you, please leave any comment (for example, "bump"), and we'll keep it open. If you have any new additional information—in particular, if this is still reproducible in the latest version of Electron or in the beta—please include it with your comment!

[renambot]

Still there on 30.0.0 macOS