Go Requires Chilkat v11.7.0+

Deflate Compression Level When Optimizing a PDF

See more PDF Optimization Examples

Demonstrates compressionLevel, which is the deflate level (1 to 9, 9 by default) used for every stream the optimizer re-encodes. Level 9 is the smallest and the slowest; level 1 is the quickest. The difference is usually a percent or two, so level 9 is the right default for a file that will be downloaded many times, and a lower level is worth considering only when a server optimizes PDFs on the fly. A value outside 1 to 9 is an error. Go

    success := false

    //  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 watersense_accomplishments.pdf

    fac := chilkat.NewFileAccess()
    json := chilkat.NewJsonObject()
    jsonOut := chilkat.NewJsonObject()

    pdf1 := chilkat.NewPdf()
    success = pdf1.LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
    if success == false {
        fmt.Println(pdf1.LastErrorText())
        fac.DisposeFileAccess()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        pdf1.DisposePdf()
        return
    }

    json.UpdateInt("compressionLevel",1)
    success = pdf1.Optimize("optimize",json,jsonOut)
    if success == false {
        fmt.Println(pdf1.LastErrorText())
        fac.DisposeFileAccess()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        pdf1.DisposePdf()
        return
    }

    success = pdf1.WriteFile("qa_output/watersense_level1.pdf")
    if success == false {
        fmt.Println(pdf1.LastErrorText())
        fac.DisposeFileAccess()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        pdf1.DisposePdf()
        return
    }

    fmt.Println("level 1: ", fac.FileSize("qa_output/watersense_level1.pdf"))

    pdf9 := chilkat.NewPdf()
    success = pdf9.LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
    if success == false {
        fmt.Println(pdf9.LastErrorText())
        fac.DisposeFileAccess()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        pdf1.DisposePdf()
        pdf9.DisposePdf()
        return
    }

    json.UpdateInt("compressionLevel",9)
    success = pdf9.Optimize("optimize",json,jsonOut)
    if success == false {
        fmt.Println(pdf9.LastErrorText())
        fac.DisposeFileAccess()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        pdf1.DisposePdf()
        pdf9.DisposePdf()
        return
    }

    success = pdf9.WriteFile("qa_output/watersense_level9.pdf")
    if success == false {
        fmt.Println(pdf9.LastErrorText())
        fac.DisposeFileAccess()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        pdf1.DisposePdf()
        pdf9.DisposePdf()
        return
    }

    fmt.Println("level 9: ", fac.FileSize("qa_output/watersense_level9.pdf"))

    //  A level outside 1..9 fails, and LastErrorText says why.
    pdfBad := chilkat.NewPdf()
    success = pdfBad.LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
    if success == false {
        fmt.Println(pdfBad.LastErrorText())
        fac.DisposeFileAccess()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        pdf1.DisposePdf()
        pdf9.DisposePdf()
        pdfBad.DisposePdf()
        return
    }

    json.UpdateInt("compressionLevel",12)
    success = pdfBad.Optimize("optimize",json,jsonOut)
    if success == false {
        fmt.Println("compressionLevel 12 was refused, as it should be.")
    }


    fac.DisposeFileAccess()
    json.DisposeJsonObject()
    jsonOut.DisposeJsonObject()
    pdf1.DisposePdf()
    pdf9.DisposePdf()
    pdfBad.DisposePdf()