9 Replies Latest reply on Nov 2, 2006 11:26 AM by kglad

    Evaluate an api drawn number like nintendo brain age

    Brian the Lion
      Hi all,

      First of all thanks’ for looking at this post!

      I'm trying to build a game for a kid's website that teaches them how to write numbers. It's quite simple in a sense that the user will be shown an example of how to write the number 5 and are then asked to try it themselves by drawing it. I have the API drawing bit working - all ok there. What I'm trying to understand or question is the ability to evaluate what they've drawn.

      I'm sure this might be possible as I saw a shinobi game site some time ago that required you to do something similar where you had to write a Chinese character to enter the page.

      The concept of the game is part of an on-going section of a kid’s site and this is the next step.

      As an example: I'm trying to create something similar to a PDA where you can free write and the characters are recognised or much like brain age on the Nintendo DS - if any of you are playing it.

      It intends to be very simple by only recognising numbers 1 – 9. In fact it will be even simpler than recognising characters as it’s more of a comparison of what the user draws to what has been asked of them.

      So my question is:

      Is this possible? Simple character recognition or the ability to compare a number 5 to a hand drawn number 5

      I would appreciate any feedback on this or links to sites or books that may hold the answers on this topic.

      Once again - thanks for your time
        • 1. Re: Evaluate an api drawn number like nintendo brain age
          Level 7
          Well, sure it's possible - lots of handhelds for instance have the ability
          to interpret handwritten notes etc. Doesn't mean it's going to be easy tho!
          Here's a start for you:

          http://www.google.co.uk/search?hl=en&q=character+recognition+algorithm&btnG=Google+Search& meta=



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          • 2. Re: Evaluate an api drawn number like nintendo brain age
            Brian the Lion Level 1
            Wow! cheers for the reply and the link, I think I've found something that may be useful - I'll look through a few more links first though. I may have worded my original post a little wrong! the ouput is not intended for PDA, I was just trying to give an impression of what I was trying to do.

            But hey - check this out - the shinobi site was the only site I've really seen that does the kind of thing I want to do. I found this site from the page you sent and could be a good start

            http://www.gskinner.com/blog/archives/2005/03/gesture_recogni.html

            Cheers for the response :-)
            • 3. Re: Evaluate an api drawn number like nintendo brain age
              Level 7
              Hey - you're welcome! :)

              No, you didn't give the wrong impression - I realised that you weren't
              trying to do this on a PDA, just pointing out that it *has* been done, on
              PDAs, to allow handwriting recognition.

              I think it's a complex task, even if you are only attempting figures 0-9,
              so, good luck, let us know how it goes!

              Pete

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              • 4. Re: Evaluate an api drawn number like nintendo brain age
                Rothrock Level 5
                I think there has been a thread about this a while ago. A search term you might want to add are guesture or gesture recognition. I recall having seen somebody's flash implementation of the PDA style writing. It worked okay, but I could never get some of the letters to be recognized so it definitely needed some work. I've got to run now, but if you can't find it I'll look later.
                • 5. Re: Evaluate an api drawn number like nintendo brain age
                  Level 7
                  Yeah, I've seen that before. It's good as far as it goes, (and I suspect
                  this is what Rothrock is thinking of too), BUT, are you trying to assess the
                  final shape, OR, the way the shape is formed. Gesture recognition, as
                  demonstrated by Grant's piece, looks for a character to be drawn in a
                  certain way, rather than looking at the end result. If you look at the
                  gesture for '4', it's not the same an actual 4 for instance...

                  Pete

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                  • 6. Re: Evaluate an api drawn number like nintendo brain age
                    Level 7
                    Or, to put it more succinctly, gesture recognition is not the same as
                    character recognition!



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                    • 7. Re: Evaluate an api drawn number like nintendo brain age
                      Brian the Lion Level 1
                      I've been looking into this stuff all day and it all seems very heavy. I've gone back to the drawing board to see if there's a much simpler way of getting the result I want. I've been looking at a possible method of providing the user with a dotted outline of the number. The site is aimed at a very young audience and so therefore I believe I can get away with this.

                      I was thinking of creating a very simple version whereby the user draws the number with the dotted template provided on screen and concentrating on the errors rather than how well the number has been drawn - maybe a series of bad hit areas that detect when the mouse or pen line has left the intended shape / number to draw could create a variable counter that helps ***** the input. I'm thinking a grid system if you like where certain areas must not be hit - I'm not sure, it's an idea. Also the possibility of using an invisible cut out shape so the user draws within as another idea of eliminating a five being drawn as aposed to sya a four.

                      The concept of eliminating bad areas as aposed to correct areas seems a little more comprehendable at the moment.

                      Thank's for all the responses on this....I'll keep you posted with my findings

                      best
                      • 8. Re: Evaluate an api drawn number like nintendo brain age
                        Rothrock Level 5
                        A similar idea had come up before – I seem to recall it was for teaching children to properly draw letters. We had the idea of having them trace over a template, convert what they drew to a bitmap, and then use some of the bitmap methods (not sure exactly which) to compare where the drawing went astray from the template. Still a bit complex but much less than trying to do character recognition.

                        As for the difference between gesture recognition and character recognition…

                        My guess is that recognizing a properly drawn four (in the correct order) is a much more computationally complex process. So that would be why the gestural characters are simplified and have "distinguishing" characteristics emphasized. But I think the framework would be the same – starting/ending points, direction, distance, etc.

                        OH!!! And I just remembered my thinking on this whole issue. From an educational standpoint, what is the purpose of such an exercise? If you are hoping to teach students how to write with a pencil or pen you will need to be sure that you have a stylus/tablet for such interaction. I know that I can write a quite legible 5 with a pencil, but with a mouse…

                        Just a thought to think about and address before putting in huge amounts of energy to making something like this.
                        • 9. Re: Evaluate an api drawn number like nintendo brain age
                          kglad Adobe Community Professional & MVP
                          i think flash could be used to recognize characters and i don't think it would be that difficult.

                          i'd create a movieclip that consists of 9 solid squares that form a 3x3 grid. we can set their _alphas to zero, size the parent movieclip to the width and height of the drawn character, overlay the movieclip and drawn character and use hitTests between the drawn character and the 9 movieclips to generate a pattern that should be able to distinguish different characters.