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image_picker resize image #17227
Description
Is it possible at the moment to resize an image without "locking up" the Flutter app UI?
I am using the image_picker plugin to pick an image from the device's Photo Gallery and image.dart lib https://pub.dartlang.org/packages/image to resize the chosen image to a more manageable resolution and then upload it to Firebase Cloud Storage. While the image decoded and then encoded the Flutter UI locks up. Could a chosen image size be generated if passed to .getImage()?
Activity
zoechi commentedon May 14, 2018
You can try https://docs.flutter.io/flutter/foundation/compute.html
You need to copy the result back to the UI thread to upload to Cloud Storage because as far as I know currently only the UI thread is allowed to access platform channels.
vagrantrobbie commentedon May 14, 2018
EDIT: Potentially this is a Stack Overflow response
Thanks for the response.
I have this working now! After resizing the image, I write the bytes back to a temporary file, upload it and then delete the temp. It works well most of the time but I am having the odd device crash (iPhone 5s). Is there a good way to debug this?
Some times this error is thrown on the resize
[VERBOSE-2:dart_isolate.cc(713)] Isolate (149972410) 'main.dart:_spawn()' exited with an error
[VERBOSE-2:dart_error.cc(16)] isolate terminated by Isolate.kill
Is there a maximum of isolates that can be called at once? Do we need to clean them up?
urbanmania commentedon Jul 11, 2018
@vagrantrobbie did you ever get this sorted? I'm having similar problems, odd crashes on older devices.
zoechi commentedon Jul 11, 2018
@vagrantrobbie I don't think there is a hard limit of isolates, but they take up memory and if you run to many at once you can easily run out of memory.
@urbanmania please add details about the problems.
urbanmania commentedon Jul 11, 2018
ok, thanks. I'm looking at this plugin now to get around this problem https://github.com/btastic/flutter_native_image
vagrantrobbie commentedon Jul 11, 2018
@urbanmania I never really fixed the problem but with a clean run on the app and no hot reloading the error was infrequent enough for me to be happy.
ImagePicker plugin has a maxWidth property which I utilised
ImagePicker.pickImage(source: ImageSource.gallery, maxWidth: 800.0); and this was enough to fix my problem. FlutterNativeImage looks handy
urbanmania commentedon Jul 11, 2018
ah, had forgotten about that, I should look into that, thanks for reminding me of that.
zoechi commentedon Jul 12, 2018
@vagrantrobbie do you think there is still something the Flutter team needs to do?
The
ImagePickerissue you mentioned should better be reported in a new issue.vagrantrobbie commentedon Jul 13, 2018
@zoechi sorry for the late reply. I consider this closed. Thanks for following!
zoechi commentedon Jul 13, 2018
@vagrantrobbie thanks for the status update!
hyochan commentedon Sep 24, 2018
@zoechi @vagrantrobbie I think this isn't enough since we need to generate the
thumbnailfor every image in general. ThereforemaxWidthproperty is not enough. I've played around withflutter-native-imagefor this currently but I think ImagePicker should support this feature itself.zoechi commentedon Sep 24, 2018
@dooboolab I think it's better to create a new issue.
flutter-team-archive/engine@2d42c74...d7ad50c
flutter-team-archive/engine@2d42c74...d7ad50c
github-actions commentedon Sep 2, 2021
This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of
flutter doctor -vand a minimal reproduction of the issue.