DataFlex Requires Chilkat v11.7.0+

Shrink a PDF Losslessly

See more PDF Optimization Examples

Demonstrates the "optimize" operation with the default options, which is the lossless preset: nothing is resampled, recoloured or thrown away, so every page looks exactly as it did and all the text is still there. The changes are kept in memory until WriteFile (or WriteBd) is called. Note that the real saving is "fileSize" minus the size of the file that was written, not "bytesSaved": the rewrite also packs objects into object streams and writes a compact cross-reference stream, which belongs to no option. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoPdf
    Variant vJson
    Handle hoJson
    Variant vJsonOut
    Handle hoJsonOut
    Handle hoFac
    Integer iSizeBefore
    Integer iSizeAfter
    String sTemp1
    Integer iTemp1

    Move False To iSuccess

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  The PDF used in this example is available at grand_canyon_hiking_guide.pdf

    Get Create (RefClass(cComChilkatPdf)) To hoPdf
    If (Not(IsComObjectCreated(hoPdf))) Begin
        Send CreateComObject of hoPdf
    End
    Get ComLoadFile Of hoPdf "qa_data/pdf/grand_canyon_hiking_guide.pdf" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPdf To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  An empty JSON means the default options: every lossless optimization, object streams generated,
    //  old revisions dropped, deflate level 9.
    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End
    Get Create (RefClass(cComChilkatJsonObject)) To hoJsonOut
    If (Not(IsComObjectCreated(hoJsonOut))) Begin
        Send CreateComObject of hoJsonOut
    End
    Get pvComObject of hoJson to vJson
    Get pvComObject of hoJsonOut to vJsonOut
    Get ComOptimize Of hoPdf "optimize" vJson vJsonOut To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPdf To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Nothing has been written yet.  WriteFile (or WriteBd) produces the optimized PDF.
    Get ComWriteFile Of hoPdf "qa_output/grand_canyon_optimized.pdf" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPdf To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComCkFileAccess)) To hoFac
    If (Not(IsComObjectCreated(hoFac))) Begin
        Send CreateComObject of hoFac
    End
    Get ComIntOf Of hoJsonOut "fileSize" To iSizeBefore
    Get ComFileSize Of hoFac "qa_output/grand_canyon_optimized.pdf" To iSizeAfter

    Showln "before: " iSizeBefore
    Showln "after:  " iSizeAfter
    Showln "saved:  " (iSizeBefore - iSizeAfter)

    //  What the options themselves account for.  This is smaller than the real saving above, because the
    //  rewrite's own gains (object streams, the cross-reference stream, the old sections left behind)
    //  belong to no single option.
    Get ComIntOf Of hoJsonOut "bytesSaved" To iTemp1
    Showln "bytesSaved (options only): " iTemp1


End_Procedure