To calculate the Wilson lower bound, I used a confidence of 95% (i.e., z = 1.96).
I'm not saying that the Wilson lower bound is *the* way to go (as you can see, it wasn't quite enough to fix TIKA-868, although it did reduce the discrepancy from 60% - 37% = *23%* to 13% - 12% = *1%*). So this method might need some adjustments. However, it does seem to represent a significant improvement over the way things are *now*.
*A simpler alternative would be to simply discard charsets which get less alphabetic text out of the input than a different charset does. This method would be successful for all 3 of the test cases I've presented here.*
> enableInputFilter() wrecks charset detection for some short html documents
> Key: TIKA-2771
> URL: https://issues.apache.org/jira/browse/TIKA-2771 > Project: Tika
> Issue Type: Bug
> Components: detector
> Affects Versions: 1.19.1
> Reporter: Hans Brende
> Priority: Critical
> When I try to run the CharsetDetector on http://w3c.github.io/microdata-rdf/tests/0065.html I get the very strange most confident result of "IBM500" with a confidence of 60 when I enable the input filter, *even if I set the declared encoding to UTF-8*.
> This can be replicated with the following code:
> CharsetDetector detect = new CharsetDetector();
> detect.setText(("<!DOCTYPE html>\n" +
> "<div>\n" +
> " <div itemscope itemtype=\"http://schema.org/Person\" id=\"amanda\" itemref=\"a b\"></div>\n" +
> " <p id=\"a\">Name: <span itemprop=\"name\">Amanda</span></p>\n" +
> " <p id=\"b\" itemprop=\"band\">Jazz Band</p>\n" +
> which prints:
> Match of IBM500 in fr with confidence 60
> Match of UTF-8 with confidence 57
> Match of ISO-8859-9 in tr with confidence 50
> Match of ISO-8859-1 in en with confidence 50
> Match of ISO-8859-2 in cs with confidence 12
> Match of Big5 in zh with confidence 10
> Match of EUC-KR in ko with confidence 10
> Match of EUC-JP in ja with confidence 10
> Match of GB18030 in zh with confidence 10
> Match of Shift_JIS in ja with confidence 10
> Match of UTF-16LE with confidence 10
> Match of UTF-16BE with confidence 10
> Note that if I do not set the declared encoding to UTF-8, the result is even worse, with UTF-8 falling from a confidence of 57 to 15.
> This is screwing up 1 out of 84 of my online microdata extraction tests over in Any23 (as that particular page is being rendered into complete gibberish), so I had to implement some hacky workarounds which I'd like to remove if possible.
> EDIT: This issue may be related to TIKA-2737 and [this comment|https://issues.apache.org/jira/browse/TIKA-539?focusedCommentId=13213524&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13213524].
This message was sent by Atlassian JIRA