Tcl Requires Chilkat v11.7.0+

Fit a QR Code within a Maximum Size

See more QR Code Examples

Demonstrates limiting the size of the image. render.maxWidth and render.maxHeight are the largest image allowed. With render.sizing set to shrinkToFit, QrCode starts from the module size asked for and reduces it, a whole pixel at a time, until the image fits, but never below render.minModuleSize. If it cannot fit, the call fails with noFit rather than returning a code too small to scan. 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.

set json [new_CkJsonObject]

CkJsonObject_UpdateString $json "payload.text" "https://www.chilkatsoft.com/barcode_overview.asp"

#  Ask for 10-pixel modules, but accept anything down to 3 pixels to stay within 300 x 300.
CkJsonObject_UpdateInt $json "render.moduleSize" 10
CkJsonObject_UpdateString $json "render.sizing" "shrinkToFit"
CkJsonObject_UpdateInt $json "render.minModuleSize" 3
CkJsonObject_UpdateInt $json "render.maxWidth" 300
CkJsonObject_UpdateInt $json "render.maxHeight" 300

CkJsonObject_UpdateString $json "output.path" "qa_output/qr_fit_300.png"
CkJsonObject_UpdateBool $json "output.overwrite" 1
CkJsonObject_UpdateString $json "output.return" "none"

set fmt [new_CkFormats]

set jsonOut [new_CkJsonObject]

set success [CkFormats_QrCode $fmt "generate" $json $jsonOut]
if {$success == 0} then {
    puts [CkFormats_lastErrorText $fmt]
    delete_CkJsonObject $json
    delete_CkFormats $fmt
    delete_CkJsonObject $jsonOut
    exit
}

puts "module asked for: [CkJsonObject_stringOf $jsonOut {measurements[0].requestedPitch}] pixels"
puts "module used: [CkJsonObject_IntOf $jsonOut {measurements[0].pitch}] pixels"
puts "image: [CkJsonObject_IntOf $jsonOut {measurements[0].canvasWidth}] x [CkJsonObject_IntOf $jsonOut {measurements[0].canvasHeight}] pixels"

#  The image written to qa_output/qr_fit_300.png:

#  

#  The same code cannot fit in 100 x 100 with modules of at least 3 pixels.
CkJsonObject_UpdateInt $json "render.maxWidth" 100
CkJsonObject_UpdateInt $json "render.maxHeight" 100
set success [CkFormats_QrCode $fmt "generate" $json $jsonOut]
if {$success == 0} then {
    puts "100 x 100: [CkJsonObject_stringOf $jsonOut {errors[0].code}] ([CkJsonObject_stringOf $jsonOut {errors[0].message}])"
}

#  Sample output:

#  module asked for: 10 pixels
#  module used: 7 pixels
#  image: 287 x 287 pixels
#  100 x 100: noFit (the symbol does not fit the render constraints: minModuleSize)

delete_CkJsonObject $json
delete_CkFormats $fmt
delete_CkJsonObject $jsonOut