忍者ブログ
12 11 10 9 8 7 6 5 3 1
×

[PR]上記の広告は3ヶ月以上新規記事投稿のないブログに表示されています。新しい記事を書く事で広告が消えます。

It's monday yet again and I'm back at the usual spot in front of the computer. Why, oh why is the weekend so short? I really could use just one more day to get some proper rest, but no. I have to go to work. Oh well. No work no pay. In some of my spare time this saturday I've decided to examin the QR code a little bit closer to check what it can and cannot handle. Since the code must be able to handle some distortion, I checked out how much distortion would it take to make the code unreadable. Let's take a look at the source code that I used.



This is your normal code which is automatically generated by any QR application. I always use the lowest possible density for short messages. This one contains one word only.

After generating the base image, I started removing the pixels from it one by one, checking which can be removed and which cannot. This is what I got. You can't remove a single pixel from this one and still read it. This is the lowest pixel count version that is still recognisable by the QR readers.



As you can see, alot of information was removed and it still works. I don't know if it works with all the readers, but it worked with mine. Now if the code can handle removal of the pixels, it should also handle additional pixels, right? I checked that aswell and this is the result.



Now this is cool. You will certainly be able to see the amount of black pixels added and the code still works. Add a single pixel to what you can see right now and it breaks, which means this is the maximum amount of additional pixels this particular code can handle.

This would only mean that the codes contain additional data to make ensure the visibility of the message. If a reader can't make out the information, it has the additional pointers to help it. Those were either removed or blacked out in both tests.

As you may, or may not know, there are password protected QR codes. Your reader will ask you for the password before you can read the message hidden inside. I think I'll play around a bit with those during the next weekend, so if you're curious, stay tuned.
PR

無題
I think QR-code that U use also may be found here: http://en.wikipedia.org/wiki/QR_Code
am I right?
andy 2008 . 03 . 19(Wed)03:19:58 Edit
Re:無題
That's the exact same code because I was the one who added the error correction info in the Wikipedia article. If you use a QR code reader to check what it says, you'll find further confirmation.
2008 . 03 . 1904:00
Trackback to this article →
Calendar
11 2016/12 01
S M T W T F S
1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31

TweetFeed
    New Comments

    (02/24)
    (02/23)
    (02/23)
    (02/23)
    Hi
    (02/21)
    Play-Asia
    The Cat
    Profile


    Contact
    Blog Search
    Poison
    Analyzer


    . . . . . . .
    Share |
    HOMEへ戻る
    忍者ブログ | [PR]
    shinobi.jp