Hacker News Reader

Comment by rootbear | Hacker News Reader

Over twenty years ago, I was in a conversation with a developer who was working on Japanese handwriting recognition for the Go PenPoint OS. He told me that stroke order, which is supposed to be consistent in Japanese writing, was a big help. It's interesting that this article says that there was a need to "achieve stroke-order independence". I'm wondering what the issues are here and why stroke order was useful in the 90s but not considered so now. I'm also not sure if the developer I spoke to was concerned with Chinese input as well, or just Japanese, and how that might affect the methods used.

View on HN

I don't know much about Japanese, but in written Chinese, the stroke order is less likely to be consistent. One of the challenges for early leaners of writing Chinese characters is to "get the stroke order right", and many, even sufficiently educated adults could struggle getting all orders right. Also, writing Chinese characters in cursive often requires different stroke orders for the same character due to aesthetic reasons, and the boundary between print and cursive style in hand writings could be very blurry. Therefore, I could see stroke-order becomes a very noisy, inconsistent and less reliable input.

With handwriting recognition you differ between online and offline recognition. With online you have the stroke order, which helps a lot for character segmentation. Character segmentation is the unsolved problem for handwriting recognition, at least for Latin scripts. With offline you only have the image of a word. If you depend on online information you can't recognize text from images taken with a camera.

Segmentation is not needed for a modern deep learning system, since this is learned by the neural network. It’s a solved problem for many handwritting recognition problems.

Would love to see a system or a paper which did solve this problem.

Standard stroke order for any given character is occasionally different between Chinese and Japanese [1].

Characters also have different variants, e.g. the radical on top of 'grass' 草 has variants with 3, 4, or even 6 strokes [1]. There are two 4-stroke variants that look different and have different stroke order. Plus cursive handwriting will often elide and merge strokes to make things flow better.

Full stroke order independence is probably unrealistic (some parts of a character will always be written last), but allowing for some local inversions is probably necessary.

[1] https://en.wikipedia.org/wiki/Stroke_order#Stroke_order_per_...

[2] https://en.wiktionary.org/wiki/%E8%89%B9

Deleted comment

Before you ask someone to correct you, you needed to raise examples which Chinese education isn't rigorous. AFAIK, East-Asian countries education are all consistent and rigorous and focus very much on STEM. And they all focus on good hand writing on paper. Good handwriting can probably get a few extra marks on writing exams. But after their students finished high-school and attended college entrance exam, fewer people keep up with good hand writing since everyone types right now.

> I'm wondering what the issues are here and why stroke order was useful in the 90s but not considered so now

People expect more from technology.

So while in the 90's it was amazing that technology could get the correct character if you clearly wrote each character with the correct stroke order, today, people expect to be able to hurriedly scrawl (possibly in cursive) and have the system get the right character. Those are two very different problems.

See for example the images of cursive characters in the linked article. They are very common variations, containing simplifications, but they don't follow anything like the correct stroke order for the character except maybe in broad terms such as writing from left-to-right, or top-to-bottom

From context I assume it's referring to offline recognition where there's no stroke order to work with.

I doubt it's anything to do with the fact that people are inconsistent about stroke order - that's true, but they're not that inconsistent and there's no reason a recognition system couldn't account for variations in order just as it does for other factors.

I'm trying to learn Chinese, and sometimes get the stroke order wrong. All the other keyboards are phonetic systems, not graphical systems to type the characters. I appreciate the stroke-order independence so I don't have to try so many times to find the character I need.

I don't think I knew that there even was a cursive form of Chinese. That does complicate things, especially the "off-line" case where all one has is a static image.

Reply on news.ycombinator.com