Create searchable PDF and compression

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  • Last Post 13 May 2016
Nikola posted this 12 May 2016

Hi There,
I have high resolution multicolor JPEG images that come from a scanner. Then they are exported to searchable PDF's by using ABBYY FineReader SDK 10. Here is piece of C# code : var pdfExportParams = FineReaderWrapper.Engine.CreatePDFExportParams(); pdfExportParams.Resolution = Resolution; pdfExportParams.Colority = PDFColorityModeEnum.PCM_KeepColority; pdfExportParams.PictureCompressionParams.JpegQuality = 100; pdfExportParams.ResolutionType = PDFResolutionTypeEnum.PRT_Source; pdfExportParams.Scenario = PDFExportScenarioEnum.PES_MaxQuality; pdfExportParams.TextExportMode = PDFExportModeEnum.PEM_ImageOnText; document.Export(pathToPDF, FileExportFormatEnum.FEF_PDF, pdfExportParams);
After exporting the JPEGs to searchable PDF I see significant degradation of the image quality overall. Is it possible to preserve image quality and resolution as much as possible and minimize(or even better avoid) additional compression?What are the best practices here?

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Oksana Serdyuk posted this 12 May 2016

Please try also to use the below export settings additionally to yours:

[PDFExportParams]
CorrectColorDepth = False
MRCMode = MRC_Disable

[PDFPictureCompressionParams] 
BwFormat = EPF_JBIG2
GrayFormat = EPF_LZWGray (try the different values for this property)
ColorFormat = EPF_LZWColor (try the different values for this property)
EnableSharpenFilter = True

To get more recommendations, please send your original images for our tests. You can find your region Support Team contacts here.

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  • Nikola
Nikola posted this 12 May 2016

Hi Oksana,
Thanks for recommendations. I played with parameters and CorrectColorDepth improved situation a little bit, however pdf quality still is not as expected. Generated PDF file has a size smaller than original image. Unfortunately, I don't have EnableSharpenFilter parameter. Did I miss something?. I've sent one of the images to Tech Support.

Oksana Serdyuk posted this 13 May 2016

We have received your email with the image and have forwarded to our European Office for further investigation. They will answer you as soon as possible.

As for the EnableSharpenFilter property of the PDFPictureCompressionParams object, it is supported beginning from Version 10.5, Release 1 (build 10.5.0.58). Possible you use an earlier version.

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