You may try to use tesseract tool to check data extraction from pdf or images and then go forward accordingly. As far as I understand the PDF is an image and not data. The searchable PDF actually overlays the selectable text as hidden text over the PDF image. These PDFs can be indexed and extracted. These are mostly supported in english and other latin derivatives. You may face problems to extract/index text based on any other language. Handwritten text converted to PDFs are next to impossible to index/extract. Apache Tika may be the solution you are looking for On Wed 11 Jul, 2018, 9:12 PM Walter Underwood, <wun...@wunderwood.org> wrote:
> PDF is not a structured document format. It is a printer control format. > > PDF does not have a paragraph marker. Instead, it says to move > to this spot on the page, choose this font, and print this letter. For a > paragraph, it moves farther. For the next letter in a word, it moves a > little bit. Extracting paragraphs from that is a difficult pattern > recognition > problem. > > I worked with a PDF of a two-column magazine article that printed > the first line of column 1, then the first line of column 2, then the > second line of column 1, and so on. If a line ended with a hyphenated > word, too bad. > > Extracting structure from a PDF document is somewhere between > very hard and impossible. Someone I worked with said that getting > structured text from PDF was like turning hamburger back into a cow. > > Since Acrobat 5, there is “tagged PDF”. I’m not sure how widely that > is used. It appears to be an accessibility feature, so it still might not > be useful for search. > > wunder > Walter Underwood > wun...@wunderwood.org > http://observer.wunderwood.org/ (my blog) > > > On Jul 11, 2018, at 8:07 AM, Erick Erickson <erickerick...@gmail.com> > wrote: > > > > Solr will not do this automatically, the Extracting Request Handler > > simply indexes the entire contents of the doc without regard to things > > like paragraphs etc. Ditto with HTML. This is actually a task that > > requires getting into Tika and using all the bells and whistles there. > > > > I'd recommend two things: > > > > 1> Take the PDF parsing offline, i.e. in a separate client. There are > > many reasons for this, in particular you can attempt to do what you're > > asking. See: https://lucidworks.com/2012/02/14/indexing-with-solrj/ > > > > 2> Talk to the Tika folks about the best ways to make Tika return the > > information such that you can index them and get what you'd like. > > > > Best, > > Erick > > > > On Wed, Jul 11, 2018 at 6:35 AM, Rahul Prasad Dwivedi > > <rdwiv...@bestpeers.com> wrote: > >> Hello Team, > >> > >> I am using the Solr for indexing and searching for pdf document > >> > >> I have go through with your website document and installed solr but > unable > >> to index and search the document. > >> > >> For example: Suppose we have a PDF file which have no of paragraph with > >> separate heading. > >> > >> So If I search for the title on indexed pdf the result should be contain > >> the paragraph from where the title belongs. > >> > >> I am unable to perform this task. > >> > >> I have run the below command for upload the pdf > >> > >> *bin/post -c gettingstarted pdf-sample.pdf* > >> > >> and for searching I am running the command > >> > >> *curl http://localhost:8983/solr/gettingstarted/select?q='* > >> <http://localhost:8983/solr/gettingstarted/select?q='*>'* > >> > >> Please suggest me anything and let me know if I am missing anything > >> > >> Thanks, > >> > >> Rahul > >
