Ruby Requires Chilkat v11.7.0+

QR Code Colors and Transparent Background

See more QR Code Examples

Demonstrates colored QR codes. render.foreground is the color of the dark modules and render.background the color behind them, each as #RRGGBB. Either can instead be an object with a color and an opacity from 0 to 1, and a background opacity of 0 gives a PNG with a transparent background to place over a page or a design. Readers need contrast: keep the modules clearly darker than whatever ends up behind them. Ruby

require 'chilkat'

success = false

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

fmt = Chilkat::CkFormats.new()
jsonOut = Chilkat::CkJsonObject.new()

#  Dark blue modules on a pale yellow background.
json = Chilkat::CkJsonObject.new()
json.UpdateString("payload.text","https://www.chilkatsoft.com/")
json.UpdateInt("render.moduleSize",6)
json.UpdateString("render.foreground","#1B3A6B")
json.UpdateString("render.background","#FFF8DC")
json.UpdateString("output.path","qa_output/qr_blue.png")
json.UpdateBool("output.overwrite",true)
json.UpdateString("output.return","none")
success = fmt.QrCode("generate",json,jsonOut)
if (success == false)
    print fmt.lastErrorText() + "\n";
    exit
end

print "colored: " + jsonOut.stringOf("outputs[0].path") + ", " + jsonOut.IntOf("outputs[0].byteCount").to_s() + " bytes" + "\n";

#  The image written to qa_output/qr_blue.png:

#  

#  The same modules on a fully transparent background.
json2 = Chilkat::CkJsonObject.new()
json2.UpdateString("payload.text","https://www.chilkatsoft.com/")
json2.UpdateInt("render.moduleSize",6)
json2.UpdateString("render.foreground","#1B3A6B")
json2.UpdateString("render.background.color","#FFFFFF")
json2.UpdateNumber("render.background.opacity","0")
json2.UpdateString("output.path","qa_output/qr_transparent.png")
json2.UpdateBool("output.overwrite",true)
json2.UpdateString("output.return","none")
success = fmt.QrCode("generate",json2,jsonOut)
if (success == false)
    print fmt.lastErrorText() + "\n";
    exit
end

print "transparent: " + jsonOut.stringOf("outputs[0].path") + ", " + jsonOut.IntOf("outputs[0].byteCount").to_s() + " bytes" + "\n";

#  qa_output/qr_transparent.png, placed here over a checkerboard and over a colored page
#  to show that whatever is behind the image shows through:

#  

#  Sample output:

#  colored: qa_output/qr_blue.png, 1345 bytes
#  transparent: qa_output/qr_transparent.png, 1377 bytes