PDFBox获取缩写的内容含义

Question

I'm having problems with PDFBox, java library. I'm trying to work on pdfs' structures and to do that without losing information I'm using PDPage.getContents() instead of a text stripper.

Problem being, it displays the content with a lot of abbreviations and number and such for which I was not able to find an explanation on the website.

An example:

BT
0.001 Tc
1.2045 TL
9.9626 0 0 9.9626 53.04069 571.90505 Tm
[(con)26.6(t)4.4(aining)-378.3(their)-378.2(a)-4.9(sso)-29(ciated)-358.9(eigen)26.6(v)59(alues)] TJ
ET
BT
0 Tc
0 TL
/F8 1 Tf
9.9626 0 0 9.9626 226.08209 571.90505 Tm
[(\012)] TJ
ET
BT
/F11 1 Tf
6.9738 0 0 6.9738 231.84 570.465 Tm
[(d)] TJ
ET
BT
0.0002 Tc
/F5 1 Tf
9.9626 0 0 9.9626 236.64 571.905 Tm
[(,)-372.5(i)0.9(n)-383.8(d)1.7(escending)-379.1(o)-5.7(r)-5.6(der)-5.6(.)-360.4(Beca)-5.7(use)-362.4(t)3.6(he)] TJ
ET
BT
-0.0008 Tc
1.2045 TL
9.9626 0 0 9.9626 53.04024 559.90505 Tm
[(co)17.4(v)57.2(a)-6.7(r)-6.6(i)-0.1(a)-6.7(n)0.7(ce)-267(ma)-6.7(tr)-6.6(ix)-280(is)-280.9(symmetr)-6.6(ic)-279.1(a)-6.7(n)0.7(d)-288.4(s)-3.8(emip)-23.4(o)-6.7(s)-3.8(itiv)21.1(e)-279.1(d)0.7(e“nite,)-289.1(t)2.6(he)-291.1(eig)-6.7(e)-2(n)24.8(v)21.1(ecto)-6.7(r)-6.6(s)-256.8(a)-6.7(r)-6.6(e)] TJ
ET

I was able to translate some of the simple obvious ones (ET = end text, BT = begin text) but basically everything else I can't be sure. The numbers next to "syllables" seem to be doing something with position.

Of particular interest to me are the /F5, /F7, .. ; They seem to have to do with the format of the text that comes after them, but only knowing this can't really help for general pdf analysis, I need to have a bit more information.

I will gladly accept any piece of information which might be of use. Thank you in advance :)

Answer 1

The best place to start is Annex A (on the left) "operator summary" in the PDF 32000 specification , or page 645. In the beginning, I used it all the time.

In your example, "Tf" is "select font". To find out what the font is, look up the name in the resource dictionary with PDFDebugger, or hover the mouse cursor over "Tf" and wait for the font name to be displayed. Here's an example:

So /TT2 is a Verdana,Bold font subset.