Decoding freezes UI

[NaikSoftware]

Decoding (math operations) proceeds in UI isolate. This cause lags when scrolling list with images (like Instagram feed).

[ahalunetsvisionable]

@NaikSoftware You can check my MR
In dart 2.15 was released isolates groups. Its better than to use worker_manager dependency.

[Solido]

Thank you guys for taking care of the best way to handle decoding.
Update has been pushed mixing your suggestions.
Can you confirm it is OK and then I'll close.
Regards

[KoheiKanagu]

I think you need to use isolate because the Future method blocks the UI thread.

[fingerart]

I've been using this library for a long time, and I noticed a slight lag when scrolling through images. I always thought it was a problem with my program, but I recently discovered that it was caused by this library.