I'd like to transplant this.

[nealehardt]

I'd like to transplant this.

[NealEhardt]

Hi there,

I think that's a great idea. JavaScript has much less overhead than Java - people would probably start using it. You are welcome to copy it and use it for anything, including profit. I plan to explicitly add a copyleft license at some point.

As far as the task of porting goes, I think it can be done. MainPanel.form needs to be implemented in HTML. The tricky bit is that this application uses several threads: UI, slow repainter, segmenter updater, and save/load. JavaScript is not great with multithreading. JS only has a UI thread (or queue), so the convention is to break background tasks into small, queueable events so the UI isn't blocked. Save/load tasks can likely be handled by an external async library. The slow repainter can be implemented in the UI queue with repeated calls to setTimeout. The segmenter updater will be most difficult to port, but luckily its work is already in queue form.

So yes, I think it's reasonable to do it. I'll be around if you have any questions.

[zgldh]

I'm glad your approval. It's a great tool, so I think it should be well known someday. Thousands future applications need this feature.

As you mentioned the multithreading, it can be implemented by Web Worker.

Thanks for your advice.

[NealEhardt]

You're right, it looks like web workers have pretty good browser support, except for Android before 4.4 (1 year ago).

But WebGL can't be used in a worker, so images need to be passed back and forth as JSON. The best way is probably a 2D array of numbers, where each number is a 32-bit integer representing a single pixel's color 0xAARRGGBB.

Most of Segmenter.java will be done in a single worker. The user's image and annotations are passed in as new Segmenter(image), then user paint is passed in as addControlPoint(x, y, isPositive) and the image is returned with its alpha channel altered, along with the edge path to be traced on screen.

I guess I'll close this issue since you have permission.