My goal is to retrieve data from PDF which may be in table structure to an excel file.
using LocationTextExtractionStrategy with iTextSharp we can get the string data in plain text with page content in left to right manner.
How can I move forward such that during
PdfTextExtractor.GetTextFromPage(reader, i, new LocationTextExtractionStrategy())
I could make the text retain its coordinate in the resulting string.
As for instance if the first line in the pdf has text aligned to right, then the resulting string must be containing trailing space or spaces keeping the content right aligned.
Please give some suggestions, how I may proceed to achieve the same.
Its very important to understand that PDFs have no support for tables. Anything that looks like a table is really just a bunch of text placed at specific locations over a background of lines. This is very important and you need to keep this in mind as you work on this.
That said, you need to subclass TextExtractionStrategy and pass that into GetTextFromPage(). See this post for a simple example of that. Then see this post for a more complex example of subclassing. The latter isn't completely relevant to your goal but it does show some more complex things that you can do.
Related
It seems like it's simply more straightforward to hard-code the text values. In an event that these values should be changed it seems like it would be more logical to search for the relevant UI element in each activity's xml layout file rather than look through the entire strings.xml. Of course if you have certain UI elements across multiple activities that all share the same text then this might be an exception (like a back button for instance), but generally there doesn't seem to be much advantage to storing these in the strings.xml. Am I missing something?
I will give you two reasons;
1 - Avoid duplication: all of your strings in one place. also, you can use string value many times. when you want to change it, there is one place to do the change. that makes it easier to maintain.
2 - Multi-language support: if you want to translate your strings to another language you must have all the strings in Strings.xml
let me know if you need more clarifications.
I'd like to make a custom lasered label from a user's input on a website. I have a template dxf file and I'd like to replace placeholder text with the user input. My problem is the dxf file format is very unreadable in its text format. Is there any way to make sense of the numeric data? If not are there any other formats (svg, etc) that would be easier to work with?
EDIT: The reason I've found it unreadable in terms of text is that the program (Solidworks) converted the text to curves.) At this point I'm trying to figure out how to prevent that.
AutoDesk was nice enough to document DXF syntax in great detail. Spend a couple hours understanding the documentation from the link below, and I think you will find it quite easy to parse and edit using code.
To just replace some placeholder text, it should be just as simple as reading the DXF file into a string (a dxf file is no different than a txt file), performing a text replace operation and saving it back to file. Just make sure that your placeholder text is very unique and is not contained in any of the key words in the document below (otherwise your DXF file will get corrupted). Something like "PlaceHolderText" will do the trick.
http://images.autodesk.com/adsk/files/autocad_2012_pdf_dxf-reference_enu.pdf
Edit: More Info
I do a lot of work with AutoDesk Inventor which is in direct competition with SolidWorks, so they are effectively the same tool. We were faced with a similar problem of needing to place text onto sheet metal flat pattern DXFs that came out of Inventor in order to identify the part, but Inventor simply could not do it (see, exactly the same!). One of our developers had the idea to place a very precise geometry punch onto the flat pattern. After the DXF was generated he wrote some code that parsed the DXF file and replaced the geometry with a text entity. More specifically we used a triangle with sides having each length defined to something like the 7th decimal place. You can then use one of the vertices of the triangle to position the text, including rotation. This process would be automatic, so once you write the code with the help of the document above (which won't take the long), it will just work. If your engraver can handle text the way you want it, I'd say this is a very good solution. We generate hundreds of parts every day using this code. Hope this helps.
I don't have much knowledge about VBA.
But I have a problem which I think can be solved with VBA.
I have a PDF file of 400 pages. I have an excel with page numbers and some text. Now I want this text to be copy pasted (Add Text under drawing markup in PDF tools) in the PDF.
I can do it manually but it will take 3 to 4 days. so can anybody help me and make my work easier. I wanted to do this in Excel-VBA.
I have 2013 Excel and Acrobat xi Pro.
It depends.
If the pdf has forms in it, you are of course able to fill them in a programmatic way.
If your document does not contain forms you are not going to be able to solve this problem in a trivial manner.
Why, I hear you ask?
PDF documents, despite their reputation are more like containers of instructions than they are a WYSIWYG format
instructions are bundled in groups called "objects"
objects can be compressed (DEFLATE) into streams
objects are indexed so they can be re-used (this is called the xref)
the index uses byte-offsets to get a grip on which object is where in the document
Now what would happen if you wanted to add a single character somewhere in the document
you would need to decode the streams to figure out where you're actually placing content
Once you've found the right stream, and you've inserted your character, you have also screwed up the xref table.
Nothing will work anymore
I'm curious how does PDF securing work? I can lock PDF file so system can't recognize text and manipulate with PDF file. Everything I found was about "how to lock/unlock" however nothing about "how does it work". Is there anyone who could explain it to me? Thx
The OP clarified in a comment
I mean lock on text recognition or manipulation with PDF file. There should be nothing about cryptography imho just some trick.
There are some options, among them:
You can render the text as a bitmap and include that bitmap in the PDF
-> no text information.
Or you can embed the font in question using a non-standard encoding without using standard glyph names
-> text information in an unknown encoding.
E.g. cf. the PDF analysed in this answer.
A special case: make the encoding wrong only for a few characters, maybe just one, probably a digit. This way an unalert person thinks everything was extracted ok, and only when the data is to be used, the errors start screwing things up, something which especially in case of wrong digits is hard to fix. E.g. cf. the PDF analysed in this answer.
Or you can put text in structures where text extraction software or copy&paste routines usually don't look, like creating a large pattern tile containing the text for some text area and filling the area with the matching pattern color.
-> text information present but not seen by most extractors.
E.g. cf. this answer; the technique here is used to make the text of a watermark non-extractable.
Or you can put extra text all over the page but make it invisible, e.g. under images, drawn in rendering mode 3 (invisible), located in some disabled optional content group (layer), ... Text extractors often do not check whether the text they extract actually is visible.
-> text information present but polluted by garbage text bits.
...
My problem:
I have a pdf with lots of roman characters with complex diacritical marks (e.g., ṣ, ś, ṝ, ǎ, etc.). To make it easier to search within the pdf, I would like to add an additional layer, much as one does with hocr, where the same text is present without the diacritics.
When using full-text search engines I can index multiple terms at the same position (vector) - I would like to achieve the same effect here.
I have read lots about adding a hocr layer to scanned images, but I really just want to duplicate the text layer, pass it through a script that strips the diacritics (straightforward enough) and then adds it back in as a hidden but searchable layer.
Anyone have any suggestions? (Solutions involving any platform, language, library or toolchain will be useful!)
Thanks :)
Edit: please let me know if the question is unclear.
Well I have a (slightly ugly and hackish) solution, so I thought I'd share it.
I'm using PDFMiner to extract the text, along with the co-ordinates. Then I'm using ReportLab to write the normalized versions of the text to a new pdf, in exactly the same position, as hidden text. To make the positions line up properly, I found I had to use exactly the same font, so I've used a combination of FontForge and MuPDF to extract the required font(s) from the original pdf.
Finally, having created the new pdf, I'm using pdftk to merge it with the original.
It works pretty well, but has the downside that copying text out of the pdf results in the normalized text being copied too. But this is acceptable for my present purposes, and I can't see any way around it. The pdf spec. doesn't really support my objective, and so I don't imagine I can do better than this hackish solution.
I have written something similar to add searchable text by OCR'ing images and converting it to PDF in C#. I used QuickPDF from www.quickpdf.com to create hidden white text objects on top of the image and this worked reasonably well.
In your case QuickPDF would allow you to extract the text strings along with bounding boxes and font details. You could then normalize your text and create the invisible text objects using the existing font and position information and then save it out to a new file.
This would basically give you the same PDF as you have now and also give you both the original and normalised text as you are getting now.
QuickPDF is a commercial library. If your solution works well for you then there is no used buying a commercial engine though. The nice thing though is that it only requires 1 SDK and you would look at it if you had a more than a few PDF's to convert.