Lua Requires Chilkat v11.7.0+

Exclude or Include Running Headers and Page Numbers

See more PDF Text Extraction Examples

Demonstrates the "repeatedHeadersFooters" filter. Text repeated at the same position on most pages, such as a running header and "Page N of 4" footers, is left out by default; set the filter to "include" to keep it. Lua

local chilkat = require("chilkat")

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

-- The four-page PDF used in this example is available at running_header.pdf

local pdf = chilkat.Pdf.new()
local success = pdf:load_file("qa_data/pdf/running_header.pdf")
if not success then
    print(pdf.last_error_text)
    return
end

local json = chilkat.JsonObject.new()
local jsonOut = chilkat.JsonObject.new()

-- Every page has the header "Harbor Lighthouse Society - Annual Report 2026" at the top right
-- and "Page N of 4" at the bottom.  By default both are excluded, so the text of page 2 is just
-- its heading and paragraphs.
json:update_string("pages", "2")
success = pdf:extract_text("text", json, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("---- default (repeated headers and footers excluded) ----")
print(jsonOut:string_of("text"))

-- Include them.  The detection looks at the neighbouring pages even when only one page is
-- selected, so a single page extracted on its own still loses its running head by default.
json:update_string("repeatedHeadersFooters", "include")
success = pdf:extract_text("text", json, jsonOut)
if not success then
    print(pdf.last_error_text)
    return
end

print("---- repeatedHeadersFooters: include ----")
print(jsonOut:string_of("text"))

-- Sample output:

-- ---- default (repeated headers and footers excluded) ----
-- The Work
--
-- The restoration society took ownership in 2021 with three goals: make the structure watertight, return the tower to public access, and relight the lantern with a historically accurate lens. The first two were met in the second season, and the lens arrived on loan in November.
--
-- The spiral stair is original and is the most fragile part of the building. Twelve of the ninety-one treads were cracked or missing, and the central column had corroded badly at the second landing. The treads were cast from patterns taken off an intact tread.
-- ---- repeatedHeadersFooters: include ----
-- Harbor Lighthouse Society - Annual Report 2026
--
-- The Work
--
-- The restoration society took ownership in 2021 with three goals: ...
--
-- The spiral stair is original and is the most fragile part of the building. ...
--
-- Page 2 of 4