Tcl Requires Chilkat v11.7.0+

Choose Which PDF Optimizations to Apply

See more PDF Optimization Examples

Demonstrates turning individual optimizations off. Every option is on by default except the two reserved ones; setting one to false leaves that part of the file alone. Here the old revisions are kept (so the output is an incremental update that leaves the original bytes untouched) and the fonts are not subset, which is what a workflow that will later fill in form fields or replace text needs. The "actions" in the report name only the options that did something. Tcl

load ./chilkat.dll

set success 0

#  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

set pdf [new_CkPdf]

set success [CkPdf_LoadFile $pdf "qa_data/pdf/grand_canyon_hiking_guide.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    exit
}

set json [new_CkJsonObject]

#  The options, all boolean, all true by default:
#    compressUncompressed    compress streams stored with no filter
#    recompressFlate         deflate again at the chosen level
#    replaceLegacyFilters    re-encode LZW, RunLength, ASCIIHex and ASCII85 streams as Flate
#    imagePredictors         apply a PNG predictor where it makes an image stream smaller
#    dedupeStreams           merge streams whose contents are identical
#    dedupeObjects           merge objects whose contents are identical
#    removeUnreferenced      drop objects nothing refers to
#    removeUnusedResources   drop resource entries no page uses
#    removeUnusedLayers      drop optional-content groups nothing uses
#    coalesceContent         join a page's content streams into one
#    tidyContent             remove redundant operators and white space from page content
#    subsetFonts             keep only the glyphs the document uses
#    dropOldRevisions        drop superseded revisions (a full rewrite)
#  
#  mergeFontSubsets and compactType1Fonts are reserved for a later release and are reported in
#  "skipped" when requested.  See the "Why an Optimization Was Skipped" example.

CkJsonObject_UpdateBool $json "subsetFonts" 0
CkJsonObject_UpdateBool $json "dropOldRevisions" 0

set jsonOut [new_CkJsonObject]

set success [CkPdf_Optimize $pdf "optimize" $json $jsonOut]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    exit
}

set success [CkPdf_WriteFile $pdf "qa_output/grand_canyon_some_options.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    exit
}

puts "bytesSaved: [CkJsonObject_IntOf $jsonOut bytesSaved]"

#  Only the options that actually did something appear under "actions", each with the number of
#  objects it affected and the bytes it saved.
set actions [new_CkJsonObject]

set success [CkJsonObject_ObjectOf2 $jsonOut "actions" $actions]
if {$success == 0} then {
    puts [CkJsonObject_lastErrorText $jsonOut]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    delete_CkJsonObject $actions
    exit
}

set oneAction [new_CkJsonObject]

set i 0
set numActions [CkJsonObject_get_Size $actions]
while {$i < $numActions} {
    set actionName [CkJsonObject_nameAt $actions $i]
    set success [CkJsonObject_ObjectOf2 $actions $actionName $oneAction]
    if {$success == 0} then {
        puts [CkJsonObject_lastErrorText $actions]
        delete_CkPdf $pdf
        delete_CkJsonObject $json
        delete_CkJsonObject $jsonOut
        delete_CkJsonObject $actions
        delete_CkJsonObject $oneAction
        exit
    }

    puts "$actionName: [CkJsonObject_IntOf $oneAction bytesSaved] bytes, [CkJsonObject_IntOf $oneAction count] objects"
    set i [expr $i + 1]
}

delete_CkPdf $pdf
delete_CkJsonObject $json
delete_CkJsonObject $jsonOut
delete_CkJsonObject $actions
delete_CkJsonObject $oneAction