Our office has hundreds of PDF files created from AutoCAD drawings. These PDF files are not text searchable (OCR) and my task is to make them text searchable.
Using Acrobat 8, I open one of my PDF files. From the pull down menu “Document” I select “OCR Text Recognition” then select “Recognize text using OCR.” I get the following message:
“Acrobat could not perform recognition (OCR) on this page because: The resolution of this page image is below the minimum of 72 dpi.”
So I go to the pull down menu “Document” again and select “Optimize scanned PDF.” A window pops up. There’s a sliding bar that I move from “Small size” to “High Quality”. Everything else stays at default settings. I click “OK”.
Then I go back to the pull down menu “Document” again and select “OCR Text Recognition”, then select “Recognize text using OCR”.
The result is a text searchable (OCR) document, but the drawing quality is poor. It looks pixilated (ugly raster). A printed hard copy looks bad.
What am I doing wrong? How do I convert a non-text searchable PDF to a text searchable PDF and still have a good looking document?
Thanks so much for your help!
Converting Regular PDF to OCR PDF
2007-10-17 09:56:12
My Product Information:
Acrobat Pro 8, Windows
Acrobat Pro 8, Windows
2009-04-08 10:32:33
#2
Lori,
I also have this 72 dpi issue and I am using the PDFMaker macro from inside Autocad. I using Acrobat 8 Pro and AutoCad 2010 and it set for at least 600 dpi.
P.S. In your message below: Is ppi a typo and you meant dpi?
Thanks,
Jim
I also have this 72 dpi issue and I am using the PDFMaker macro from inside Autocad. I using Acrobat 8 Pro and AutoCad 2010 and it set for at least 600 dpi.
P.S. In your message below: Is ppi a typo and you meant dpi?
Thanks,
Jim
2009-04-08 19:13:56
#3
Hi,
No typo...
ppi (for the "electronic" image) is pixels per inch.
dpi (for the printer generating hard copy) is dots per inch.
(& who said language was "dry"? )Be well...
No typo...
ppi (for the "electronic" image) is pixels per inch.
dpi (for the printer generating hard copy) is dots per inch.
(& who said language was "dry"? )Be well...
In order to run OCR Text Recognition on a PDF "after" it has been scanned the files need to be scanned at 72 ppi or higher. Black and white scanning at 300 ppi produces the best results for text conversion. Do you know what resolution your documents have been scanned at?
Is it possible for you to convert your files to PDF using the PDFMaker macro from inside Autocad? -- then you can avoid scanning issues.
Keep us posted,
Lori
Lori Kassuba is an AUC Expert and Community Manager for AcrobatUsers.com.