mediapipe: ImageSegmenter creation from Web Worker hangs on iOS

Have I written custom code (as opposed to using a stock example script provided in MediaPipe)

Yes

OS Platform and Distribution

iOS 16.5.1

Mobile device if the issue happens on mobile device

iPhone X

Browser and version if the issue happens on browser

Safari 16.5.1, Chrome 115.0.5790.160

Programming Language and version

JavaScript

MediaPipe version

0.10.3

Bazel version

No response

Solution

ImageSegmenter

Android Studio, NDK, SDK versions (if issue is related to building in Android environment)

No response

Xcode & Tulsi version (if issue is related to building for iOS)

No response

Describe the actual behavior

When the ImageSegmenter is created in a Web Worker on iOS Safari or iOS Chrome, createFromOptions never returns, or at least, it doesn't return in under 60 seconds.

When run on the main thread, createFromOptions works as expected on iOS.

Describe the expected behaviour

Since ImageSegmenter.createFromOptions works fine from Web Workers on Chromium browsers and Firefox on Windows, and it works fine on all platforms tested when not using a Web Worker, I would expect it to also work on iOS under Web Workers, or at least get some error message, or at the very least, for this to be a current, documented limitation.

Standalone code/steps you may have used to try to get what you need

Relevant code:


    initializeAsync() {
        if (!this._isInitialized && !this._isInitializing) {
            this._loc = 1;

            this._isInitializing = true;
            let taskVision;
            const module = 'https://cdn.jsdelivr.net/npm/@mediapipe/tasks-vision@0.10.3';
            import(module)
                .then((result) => {
                    this._loc = 2;

                    taskVision = result;
                    return taskVision.FilesetResolver.forVisionTasks(
                        'https://cdn.jsdelivr.net/npm/@mediapipe/tasks-vision@0.10.3/wasm'
                    );
                })
                .then((vision) => {
                    this._loc = 3;

                    const options = {
                        baseOptions: {
                            modelAssetPath:
                                'https://storage.googleapis.com/mediapipe-models/image_segmenter/selfie_segmenter/float16/latest/selfie_segmenter.tflite',
                            delegate: 'CPU'
                        },
                        runningMode: 'VIDEO',
                        outputCategoryMask: true,
                        outputConfidenceMasks: false
                    };
                    return taskVision.ImageSegmenter.createFromOptions(vision, options);
                })
                .then((segmenter) => {
                    this._loc = 4;

                    this._imageSegmenter = segmenter;
                    this._isInitialized = true;
                    this._isInitializing = false;
                });
        }
    },

### Other info / Complete Logs

_No response_