Wrong PDF when using OCR_MakeSearchable

PDF-X OCR SDK is a New product from us and intended to compliment our existing PDF and Imaging Tools to provide the Developer with an expanding set of professional tools for Optical Character Recognition tasks

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Posts: 1
Joined: Fri Nov 13, 2020 8:47 am

Wrong PDF when using OCR_MakeSearchable

Post by baumunk » Fri Nov 13, 2020 9:41 am

We test your product.
With your example application OCRDemoCsharp

Pdf contains images and text. After OCR, text in the image is searchable but text is removed.

Orignal PDF:

After OCR:

What am I doing wrong?
We are using DEMO.

If I use the same function in PDF-XChange Editor it is correct.


Code: Select all

hResult = PDFXOCR.PDFXOCR_Funcs.OCR_SetCallback(pdf, thecallback, 0);

				hResult = PDFXOCR.PDFXOCR_Funcs.OCR_LoadW(pdf, m_SourceFilename);
				if (PDFXOCR.PDFXOCR_Funcs.IS_DS_FAILED(hResult))
					MessageBox.Show("Error loading file: \n" + m_SourceFilename, "OCR Library Error");

				PDFXOCR.PDFXOCR_Funcs.PXO_Options Options = new PDFXOCR.PDFXOCR_Funcs.PXO_Options();
				Options.blacklist = "";
				Options.whitelist = "";
				Options.raster_dpi = 300;
                Options.ImageFlags = (uint) PDFXOCR.PDFXOCR_Funcs.OCR_ImageProcessingFlags.OCR_Image_NoRotate;
				Options.DataPath = m_Datapath;
				Options.lang = m_Language;
				Options.RegionMode = PDFXOCR.PDFXOCR_Funcs.OCR_RegionMode.OCR_Auto;
				Options.SecondLanguage = 0;

				IntPtr pxoPagelist = IntPtr.Zero; // null pointer passed to OCR_MakeSearchable() will result in all pages being OCRd.

                hResult = PDFXOCR.PDFXOCR_Funcs.OCR_MakeSearchable(pdf, ref Options, pxoPagelist);
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Paul - Tracker Supp
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Posts: 5140
Joined: Wed Mar 25, 2009 10:37 pm
Location: Chemainus, Canada

Re: Wrong PDF when using OCR_MakeSearchable

Post by Paul - Tracker Supp » Mon Dec 07, 2020 8:57 pm

Hi baumunk,

I did speak to one of the dev team about this. He told me the issue is reproduced and to make a formal support request ticket around this. While intended for internal use only, if you refer to RT#5394: Wrong PDF when using OCR_MakeSearchable in correspondence with us then any support staff member can get yo a status update on the ticket.

Back to the issue itself, you should see a post here with some suggestions withing 24 hours.
If posting files to this forum - you must archive the files to a ZIP, RAR or 7z file or they will not be uploaded - thank you.

Best regards

Paul O'Rorke
Tracker Support North America

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Sasha - Tracker Dev Team
Posts: 5198
Joined: Fri Nov 21, 2014 8:27 am

Re: Wrong PDF when using OCR_MakeSearchable

Post by Sasha - Tracker Dev Team » Tue Dec 08, 2020 10:42 am

Hello baumunk,

We've inspected this behavior and it seems that it's a bug. Part of the content is not being rendered and the SDK does not know about it.
But, as a temporary fix, you can try using the additional flags: OCR_Content_Original and OCR_Image_SuppressOutput. Then the text that is being lost in the rendering process will be left as is and the text for search will be put on top of it.

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