I have a data file that when I view it with vim, nano, or cat, will not be displayed properly and depending on the viewer, will be in different encodings. Here's an example line viewed by the TextEdit app on OSX:
….80RMî‘“q∂€r€mqpÄçÊ€~7€m∆
Here's with nano:
CҴPSRдϴ5^Cδ^T�-�ڴ^S�۴m�۴m�۴m�۴mT�-�ڴM�:��۴-��-�״^[m���۴]m�۶۶m�Ǫ�\�m�rN^RՅ
(I can't tell if they're the same line because they all have different lengths)
How could I decode it so it's readable?
Related
I am trying to extract data from this Japanese PDF using tabula-py (and tabula-java), but the output is gibberish. In both tabula-py and tabula-java, the output isn't human readable (definitely not Japanese characters), and there are no no error/warning messages. It does seem that the content of the PDF is processed though.
When using the standalone Tabula tool, the characters are encoded properly:
Searching online in the tabula-py and tabula-java documentation, and below are suggestions I could find, but these don't change the output.
Setting the -Dfile.encoding=utf8 (in java call to tabula-py or tabula-java)
Setting chcp 65001 (in Windows command prompt)
I understand Tabula and tabula-java (and tabula-py) use the same library, but is there something different between the two that would explain the difference in encoding output?
Background info
There is nothing unusual in this PDF compared to any other.
The text like any PDF is written in authors random order so for example the 1st PDF body Line (港区内認可保育園等一覧) is the 1262nd block of text added long after the table was started. To hear written order we can use Read Aloud, to verify character and language recognition but unless the PDF was correctly tagged it will also jump from text block to block
So internally the text is rarely tabular the first 8 lines are
1 認可保育園
0歳 1歳 2歳3歳4歳5歳 計
短時間 標準時間
001010 区立
3か月
3455-
4669
芝5-18-1-101
Thus you need text extractors that work in a grid like manner or convert the text layout into a row by row output.
This is where all extractors will be confounded as to how to output such a jumbled dense layout and generally ALL will struggle with this page.
Hence its best to use a good generic solution. It will still need data cleaning but at least you will have some thing to work on.
If you only need a zone from the page it is best to set the boundary of interest to avoid extraneous parsing.
Your "standalone Tabula tool" output is very good but could possibly be better by use pdftotext -layout and adjust some options to produce amore regular order.
Your Question
the difference in encoding output?
The Answer
The output from pdf is not the internal coding, so the desired text output is UTF-8, but PDF does not store the text as UTF-8 or unicode it simply uses numbers from a font character map. IF the map is poor everything would be gibberish, however in this case the map is good, so where does the gibberish arise? It is because that out part is not using UTF-8 and console output is rarely unicode.
You correctly show that console needs to be set to Unicode mode then the output should match (except for the density problem)
The density issue would be easier to handle if preprocessed in a flowing format such as HTML
or using a different language
So, text files can be copied and pasted to another location by copying the contents of the original file into a blank text file. This can be done with a text editor. Highlight contents of text file, copy, create new blank text file, paste in to it.
But, why can't image, audio, video, executable files, etc., be copied and pasted like this? For example, I open an executable file with a text editor, copy all of it's contents, create a new blank text file, change the extension to .exe, and paste into it (through a text editor). But, the file cannot be run. Why?
Also, I would like to be able to edit these types of files like I do with text files. Is there a way?
Because executable and media files are "binary" files. Text files are binary as well, but different. All files are created binary, but some are created more binary than others.
You're opening a binary file in a text editor. This immediately changes the semantics of the bytes. The main problem is bytes containing a value that happens to correspond to those of newline characters if it were a text file (0x0A and 0x0D), which will be rendered as a platform-dependent newline (\r\n on Windows, for example). When you copy that, you've changed either 0x0A or 0x0D to 0x0D 0x0A.
Then there's control characters or non-printable characters. Not all bytes between 0x00 and 0xFF can be represented as a character. They'll either be omitted or replaced with a displayable character.
So when you copy a text containing those, they'll be omitted or otherwise mangled.
In conclusion: you cannot reliably use text to display all possible byte values, unless you choose to encode the bytes' values, as is done using for example Base64 encoding.
If you want to edit a binary file, use an editor that is aware of those bytes: a "hex editor". Do note that changing random byte values in a binary file does not guarantee the sanity of that file: there may be checksums built into the format, and your edit will invalidate that checksum.
In my case specifically, I have bullet-points (• or #149) in my text file.
If I copy paste "•" into my Unity text field in the editor, it shows up, so I am pretty sure the bullet-point is lost in the reading process. (I checked in debug mode, and indeed the bullet-point is lost at reading).
This is how I read in my text file as a TextAsset:
TextAsset content = Resources.Load(SlideManager.slideLanguage+"\\"+fileName+" ("+SlideManager.slideNumber+")") as TextAsset;
It turns out, that the way I read is completely fine. It reads the file correctly, but the encoding of the file is ASCII, therefore the resource loader cannot interpret none ASCII characters, and drops them.
Thus, since the bullet-point is not standard ASCII, but extended ASCII character, you have to specify the encoding of your text files.
For example, set encoding to UTF-8, and then it will work. I used notepad++ to set encoding, but I am sure there are many other ways you can do it.
To set encoding in Notepad++
Click on the tab named Encoding (fifth tab from the left on the top by default), and select Convert to UTF-8.
I'm finding it difficult to parse a pdf file that's created in a non-english language. I used pdfbox and itext but couldn't find anything in there that could help parse this file. Here's the pdf file that I'm talking about: http://prapatti.com/slokas/telugu/vishnusahasranaamam.pdf The pdf says that it's created use LaTeX and Tikkana font. I have Tikkana font installed on my machine, but that didn't help. Please help me in this.
Thanks, K
When you say "parse PDF files", my first thought was that the PDF in question wasn't opening in various PDF viewers & libraries, and was therefore corrupt in some way.
But that's not the case at all. It opens just fine in Acrobat Reader X. And then I see the text on the page.
And when I copy/paste that text from the first page, I get:
Ûûp{¨¶ðQ{p{¨|={pÛû{¨>üb¶úN}l{¨d{p{¨> >Ûpû¶bp{¨}|=/}pT¶=}Nm{Z{Úpd{m}a¾Ú}mp{Ú¶¨>ztNð{øÔ_c}m{ТÁ}=N{Nzt¶ztbm}¥Ázv¬b¢Á
Á ÛûÁøÛûzÏrze¨=ztTzv}lÛzt{¨d¨c}p{Ðu{¨½ÐuÛ½{=Û Á{=Á Á ÁÛûb}ßb{q{d}p{¨ze=Vm{Ðu½Û{=Á
That's from Reader.
Much of the text in this PDF is written using various "Type 3" fonts. These fonts claim to use "WinAnsiEncoding" (Also Known As code page 1252), with a "differences" array. This differences array is wrong:
47 /BB 61 /BP /BQ 81 /C6...
The first number is the code point being replaced, the second is a Name of a character that replaces the original value at that code point.
There's no such character names as BB, BP, BQ, C9... and so on. So when you copy-paste that text, you get the above garbage.
I'm sorry, but the only reliable way to extract text from such a PDF is OCR (optical character recognition).
Eh... Long shot idea:
If you can find the specific versions of the specific fonts used to generate this PDF, you just might be able to determine the actual stream contents of known characters converted to Type 3 fonts in this way.
Once you have these known streams, you can compare them to the streams in the PDF and use that to build your own translation table.
You could either fix the existing PDF[s] (by changing the names in the encoding dictionary and Type 3 charproc entries) such that these text extractors will work correctly, or just grab the bytes out of the stream and translate them yourself.
The workflow would go something like this:
For each character in a font used in the form:
render it to PDF by itself using the same LaTeK/GhostScript versions.
Open the PDF and find the CharProc for that particular known character.
Store that stream along with the known character used to build it.
For each text byte in the PDF to be interpreted.
Get the glyph name for the given byte based on the existing encoding array
Get the "char proc" stream for that glyph name and compare it to your known char procs.
NOTE: This could be rewritten to be much more efficient with some caching, but it gets the idea across (I hope).
All that requires a fairly deep understanding of PDF and the parsing methods involved. But it just might work. Might not too...
What kind of char is this and how do I convert it to a text in c#/vb.net?
I opened a .dat file in notepad, took a screenshot and attached it here.
Your screenshot looks like the digits "0003" in box. This is a common way to display characters for which a glyph isn't available.
U+0003 is the "END OF TEXT" control character. It's unlikely to occur within a text file, but a ".dat" file might be a mixture of text and binary data.
You'll need to use a hex editor to find the exact ASCII code (assuming the file is ASCII, which seems to be an entirely incorrect assumption) that the file contains. It's safe to say that whatever byte sequence is contained in the file is not a printable character in whatever encoding the editor used to open the file, and that is why it used that graphic in place of the actual character.