Ruby Requires Chilkat v11.7.0+

Clipped, Off-Page and White-on-White Text in PDF Extraction

See more PDF Text Extraction Examples

Demonstrates the "clippedText", "offPageText" and "obscuredText" filters. Text that a reader never sees - hidden by a clipping path, outside the crop box, or drawn in the same color as the box beneath it - is excluded by default, and the quality report notes what was skipped. Each kind can be included. Ruby

require 'chilkat'

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 hidden_text.pdf

pdf = Chilkat::CkPdf.new()
success = pdf.LoadFile("qa_data/pdf/hidden_text.pdf")
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

json = Chilkat::CkJsonObject.new()
jsonOut = Chilkat::CkJsonObject.new()

#  The page has a visible paragraph plus three hidden lines: one drawn outside its clipping
#  rectangle, one below the crop box, and one in white on a white box.
success = pdf.ExtractText("text",json,jsonOut)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

print "---- default ----" + "\n";
print jsonOut.stringOf("text") + "\n";

#  The quality report says what was left out.
i = 0
count_i = jsonOut.SizeOfArray("quality.pages[0].issues")
while i < count_i
    jsonOut.put_I(i)
    print "issue: " + jsonOut.stringOf("quality.pages[0].issues[i].code") + "\n";
    i = i + 1
end

#  Include everything.
json.UpdateString("clippedText","include")
json.UpdateString("offPageText","include")
json.UpdateString("obscuredText","include")
success = pdf.ExtractText("text",json,jsonOut)
if (success == false)
    print pdf.lastErrorText() + "\n";
    exit
end

print "---- clippedText, offPageText, obscuredText: include ----" + "\n";
print jsonOut.stringOf("text") + "\n";

#  Sample output:

#  ---- default ----
#  Visible Text
#  
#  This paragraph is visible. The page also carries three kinds of text a reader never sees.
#  
#  End of the visible text.
#  issue: obscuredTextSkipped
#  issue: clippedTextSkipped
#  ---- clippedText, offPageText, obscuredText: include ----
#  Visible Text
#  
#  This paragraph is visible. The page also carries three kinds of text a reader never sees.
#  
#  CLIPPED: this line is drawn outside its clipping rectangle.
#  
#  OBSCURED: this line is white on a white box.
#  
#  End of the visible text.
#  
#  OFFPAGE: this line sits below the crop box.