[jira] [Comment Edited] (TIKA-2771) enableInputFilter() wrecks charset detection for some short html documents

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[jira] [Comment Edited] (TIKA-2771) enableInputFilter() wrecks charset detection for some short html documents

JIRA jira@apache.org

    [ https://issues.apache.org/jira/browse/TIKA-2771?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16680378#comment-16680378 ]

Hans Brende edited comment on TIKA-2771 at 11/8/18 9:26 PM:
------------------------------------------------------------

[~[hidden email]] Does Tika have a corpus of documents paired with expected encodings that I can use to test out the PR I mentioned? I'm very curious to find out how much of an improvement it is.

(*EDIT*: I should also ask: if Tika does have such a corpus of documents, is it an approximately random sampling of charsets as found on the web, or are any charsets present in greater proportion in the test corpus than found on the web?)


was (Author: hansbrende):
[~[hidden email]] Does Tika have a corpus of documents paired with expected encodings that I can use to test out the PR I mentioned? I'm very curious to find out how much of an improvement it is.

> 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:
> {code:java}
> CharsetDetector detect = new CharsetDetector();
> detect.enableInputFilter(true);
> detect.setDeclaredEncoding("UTF-8");
> 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" +
>         "</div>").getBytes(StandardCharsets.UTF_8));
> Arrays.stream(detect.detectAll()).forEach(System.out::println);
> {code}
> which prints:
> {noformat}
> 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
> {noformat}
> 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].



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