PDF文本字符串的编码 [英] Encoding of PDF text string

问题描述

我正在研究用于PDF(文本提取)的解析器.

I am working on parser for PDF (text extraction).

需要对页面进行 Flate解码(通过zlib压缩)时，我的代码可以解压缩内容流，然后输出如下内容(流对象):

When page need to be Flate Decoded (from zlib compression), my code is able to decompress content streams, and then I have output (stream object) something like below:

BT
56.8 721.3 Td 
/F2 12 Tf
[<01>2<0203>2<04>-10<0503>2<04>-2<0506070809>2<0A>1<0B>]TJ
ET

我对字符串数组(TJ的操作数)感兴趣.

I am interested in the string array (operand of TJ).

似乎此数组中包含多个十六进制编码的字符串，但是相应的十六进制值没有意义.相反，它看起来像是010203 ... lz77压缩之类的序列.

It seems like there are multiple hex encoded strings contained in this array but corresponding hex values do not make sense. Instead it appears a sequence like 010203... sort of lz77 compression.

• PDF是否具有多个压缩级别?
• 如何从字符串数组上方获取纯文本?

推荐答案

Abhishek，

这不是一个简单的问题，不幸的是，它表明您尚未阅读PDF规范.您应该这样做.

This is far from an easy question and unfortunately it shows you have not read the PDF specification. You should do so.

您可以在此处下载Acrobat SDK: http://www.adobe.com/devnet/acrobat/sdk/eula. html

You can download the Acrobat SDK here: http://www.adobe.com/devnet/acrobat/sdk/eula.html

其中一部分是PDF规范，这是一个非常繁重的文档，解释了PDF的来龙去脉(包括对问题的回答).

Part of that is the PDF Specification which is a very hefty document explaining the ins and outs of PDF (including the answer to your question).

简而言之-而不是代替阅读文档-您正在寻找的是/F2 12 Tf命令设置的字体编码中的字符值，该命令设置随后写入文本时使用的特定字体.

In short - and not as a substitute to reading the documentation - what you're looking at are character values in the encoding of the font set by the /F2 12 Tf command which sets a particular font used when writing text subsequently.

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