AutoIt Requires Chilkat v11.7.0+

QR Code Error Correction Levels

See more QR Code Examples

Demonstrates the four QR error-correction levels. L, M, Q and H allow a reader to recover the data when about 7%, 15%, 25% and 30% of the symbol is damaged or covered. More error correction leaves less room for data, so the same text needs a larger symbol at a higher level. The default is M. The example also shows boostErrorCorrection, which raises the level for free when the chosen version has room to spare. AutoIt

Local $bSuccess = False

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

$oFmt = ObjCreate("Chilkat.Formats")
$oJson = ObjCreate("Chilkat.JsonObject")
$oJsonOut = ObjCreate("Chilkat.JsonObject")
$oJson.UpdateString("payload.text","https://www.chilkatsoft.com/barcode_overview.asp")

;  Encode the same text at each level.
$oLevels = ObjCreate("Chilkat.JsonArray")
$oLevels.Load("[""L"",""M"",""Q"",""H""]")
Local $i
For $i = 0 To 3
    $oJson.UpdateString("encoding.qr.errorCorrection",$oLevels.StringAt($i))
    $bSuccess = $oFmt.QrCode("generate",$oJson,$oJsonOut)
    If ($bSuccess = False) Then
        ConsoleWrite($oFmt.LastErrorText & @CRLF)
        Exit
    EndIf

    ConsoleWrite("level " & $oLevels.StringAt($i) & ": version " & $oJsonOut.IntOf("symbols[0].selectedEncoding.version") & ", " & $oJsonOut.IntOf("symbols[0].dimensions.modulesWide") _
         & " modules wide" & @CRLF)
Next

;  The four symbols.  They hold the same text, and the higher the level, the larger the symbol:

;  

;  A symbol often has room left over.  boostErrorCorrection uses it: the level is raised
;  as far as the same version allows, so the symbol is no larger but is more robust.
$oJson2 = ObjCreate("Chilkat.JsonObject")
$oJson2.UpdateString("payload.text","https://chilkatsoft.com")
$oJson2.UpdateString("encoding.qr.errorCorrection","L")
$bSuccess = $oFmt.QrCode("generate",$oJson2,$oJsonOut)
If ($bSuccess = False) Then
    ConsoleWrite($oFmt.LastErrorText & @CRLF)
    Exit
EndIf

ConsoleWrite("level L requested: version " & $oJsonOut.IntOf("symbols[0].selectedEncoding.version") & ", level " & $oJsonOut.StringOf("symbols[0].selectedEncoding.errorCorrection") & @CRLF)

$oJson2.UpdateBool("encoding.qr.boostErrorCorrection",True)
$bSuccess = $oFmt.QrCode("generate",$oJson2,$oJsonOut)
If ($bSuccess = False) Then
    ConsoleWrite($oFmt.LastErrorText & @CRLF)
    Exit
EndIf

ConsoleWrite("level L with boost: version " & $oJsonOut.IntOf("symbols[0].selectedEncoding.version") & ", level " & $oJsonOut.StringOf("symbols[0].selectedEncoding.errorCorrection") & @CRLF)

;  Level L, and level M reached by the boost.  The two symbols are the same size:

;  

;  Sample output:

;  level L: version 3, 29 modules wide
;  level M: version 4, 33 modules wide
;  level Q: version 5, 37 modules wide
;  level H: version 6, 41 modules wide
;  level L requested: version 2, level L
;  level L with boost: version 2, level M