B4X 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. B4X

Dim success As Boolean = 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

Dim fac As ChilkatFileAccess
fac.Initialize
Dim json As ChilkatJsonObject
json.Initialize
Dim jsonOut As ChilkatJsonObject
jsonOut.Initialize

Dim pdf1 As ChilkatPdf
pdf1.Initialize("pdf1")
success = pdf1.LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
If success = False Then
    Log(pdf1.LastErrorText)
    Return
End If

json.UpdateInt("compressionLevel", 1)
success = pdf1.Optimize("optimize", json, jsonOut)
If success = False Then
    Log(pdf1.LastErrorText)
    Return
End If

success = pdf1.WriteFile("qa_output/watersense_level1.pdf")
If success = False Then
    Log(pdf1.LastErrorText)
    Return
End If

Log("level 1: " & fac.FileSize("qa_output/watersense_level1.pdf"))

Dim pdf9 As ChilkatPdf
pdf9.Initialize("pdf9")
success = pdf9.LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
If success = False Then
    Log(pdf9.LastErrorText)
    Return
End If

json.UpdateInt("compressionLevel", 9)
success = pdf9.Optimize("optimize", json, jsonOut)
If success = False Then
    Log(pdf9.LastErrorText)
    Return
End If

success = pdf9.WriteFile("qa_output/watersense_level9.pdf")
If success = False Then
    Log(pdf9.LastErrorText)
    Return
End If

Log("level 9: " & fac.FileSize("qa_output/watersense_level9.pdf"))

'  A level outside 1..9 fails, and LastErrorText says why.
Dim pdfBad As ChilkatPdf
pdfBad.Initialize("pdfBad")
success = pdfBad.LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
If success = False Then
    Log(pdfBad.LastErrorText)
    Return
End If

json.UpdateInt("compressionLevel", 12)
success = pdfBad.Optimize("optimize", json, jsonOut)
If success = False Then
    Log("compressionLevel 12 was refused, as it should be.")
End If