Single channel halos

Are you using the latest version? Is the version currently in use as reported by npm ls sharp the same as the latest version as reported by npm view sharp dist-tags.latest?

Yes, sharp@0.28.3

What are the steps to reproduce?

Do multiple operations with single channel images

What is the expected behaviour?

Perform operations trim, resize, flatten, composite, resize, flatten with single channel b-w—with the same quality as multichannel srgb. Hopefully faster too.

Are you able to provide a minimal, standalone code sample, without other dependencies, that demonstrates this problem? Available upon request.

Are you able to provide a sample image that helps explain the problem?

Faint halo / artifacts / glow around the letters:

Expected output:

What is the output of running npx envinfo --binaries --system?

  System:
    OS: macOS 10.15.7
    CPU: (16) x64 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
    Memory: 24.40 MB / 64.00 GB
    Shell: 5.7.1 - /bin/zsh
  Binaries:
    Node: 14.17.0 - ~/.asdf/installs/nodejs/14.17.0/bin/node
    Yarn: 1.22.10 - ~/.asdf/shims/yarn
    npm: 7.19.0 - ~/.asdf/installs/nodejs/14.17.0/.npm/bin/npm
    Watchman: 2021.06.07.00 - /usr/local/bin/watchman

[lovell]

No hurry, whenever you’re ready, thank you for the update.

[lovell]

Closing due to inactivity but please feel free to reopen with more details if further help is required.