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Groups > comp.os.linux.misc > #14880
| From | Unknown <dog@gmail.com> |
|---|---|
| Newsgroups | comp.os.linux.misc |
| Subject | Re: pdf & O.C.R ? |
| Date | 2015-05-27 17:10 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <pan.2015.05.27.17.12.03@gmail.com> (permalink) |
| References | <pan.2015.05.23.07.50.46@gmail.com> <bjj73c-fim.ln1@mail.binaryfoundry.ca> |
On Sat, 23 May 2015 20:46:03 -0400, John-Paul Stewart wrote: > On 23/05/15 03:49 AM, Unknown wrote: >> I'm confused and disturbed that xpdf of: >> http://www.inf.ethz.ch/personal/wirth/ProjectOberon/PO.Computer.pdf >> is perfect to the pixel, with maximum magnification [400%], which is >> expected, since it's computer-font generated, whereas: >> http://www.northernlaw.co.za/images/stories/files/actsandbills/COMPANY% >> 20LAW%20ACT.pdf >> shows blotchy and fibers as if it's a photo-of-a-paper-copy. >> >> And scanned copies of papers are apparently normal. >> >> BUT!! How is it that xpdf allows me to extract the text, via mouse-copy >> from COMPANY%20LAW%20ACT.pdf ? >> That would mean that the mouse-driver is doing O.C.R. ?! > > Why would you think the mouse driver is doing OCR? > OBVIOUSLY from my description there's pdftotext happening via mouse. > A PDF file can contain both text and images. It is common when scanning > paper documents to turn them into a so-called "searchable PDF" that > contains the scanned image of the page overlaid on top of the (OCRed) > text. So what you see visually is the (possibly blurry) picture, while > what the mouse is copying (and pdftotext is extracting) is the text > that's hidden underneath. > > Adobe's own Acrobat software can create such "searchable PDF" files. I'm > sure there are other tools, too. What extreme deception. There's a layer of pixel-perfect pdftotext-able, covered by the blurry photo-image ?!
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pdf & O.C.R ? Unknown <dog@gmail.com> - 2015-05-23 07:49 +0000
Re: pdf & O.C.R ? Bob Tennent <BobT@cs.queensu.ca> - 2015-05-23 11:13 +0000
Re: pdf & O.C.R ? Unknown <dog@gmail.com> - 2015-05-27 17:11 +0000
Re: pdf & O.C.R ? John-Paul Stewart <jpstewart@sympatico.ca> - 2015-05-23 20:46 -0400
Re: pdf & O.C.R ? Joe Beanfish <joebeanfish@nospam.duh> - 2015-05-26 13:26 +0000
Re: pdf & O.C.R ? Unknown <dog@gmail.com> - 2015-06-13 13:29 +0000
Re: pdf & O.C.R ? Robert Heller <heller@deepsoft.com> - 2015-06-13 12:52 -0500
Re: pdf & O.C.R ? Unknown <dog@gmail.com> - 2015-05-27 17:10 +0000
Re: pdf & O.C.R ? John-Paul Stewart <jpstewart@sympatico.ca> - 2015-05-29 20:31 -0400
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