getImageData slow

This is a super component and we’ve been using extensively in a project. Happy to contribute should someone be able to point me in the right direction:

I’m implementing a component that has to use getImageData() multiple times in a loop. Of the 10 or so calls in each loop, some take up to 500ms to resolve, others just 5ms. I’m guessing that the performance issue relates to the messaging between RN and the WebView, rather than the getImageData() call.

1. Is there a work around?
2. If not, Would implementing a custom function like getImageDataMultiple(RectangleArray) likely solve the issue by reducing the RN -> WebView interaction to a single call?
3. Would it be accepted back into the source? I’d prefer not to maintain a custom fork if poss.

[runrevben]

Hi @iddan, we changed our code again as per your comments to return the promises and then resolved all our data once then promise.all returned. Unfortunately the performance improvement was minimal.

I’d be interested in your thoughts re implementing batching in your code. I think that would help us and others as it appears this library is the best on out there for Canvas and ReactNative. I’d be happy to show you what our app is doing and even get a developer to try and help implement the changes if that’s useful.

[runrevben]

OK thanks. We are currently using a mixture of promise.all and await… I’ll look at refactoring to remove the await.

Batching sounds like a great idea though. If you think that’s something that can realistically be added we’d be happy to help with development, unless it’s straightforward for you? I’m expecting our app will increase its dependance on getImageData so being able to batch would be a bit benefit.

Cheers,

Ben