Configure with JSON

This document describes the JSON format understood by the sc_barcode_scanner_settings_new_from_json() function.

JSON Format

The top-level must always be a dictionary (object) containing one or more key-value pairs. In the simplest form, an empty dictionary can be passed to the function. This will return a default barcode scanner settings instance with all symbologies disabled. All other properties have their default value. In general, missing properties are left at their default value, so only the properties that need to be changed away from their default need to be specified. Key-value pairs not understood the by JSON parser are ignored as if they were not specified.

The following table shows the symbology names understood by the JSON parser:

Click to expand

Symbology	JSON Name (case is ignored)
ArUco	aruco
Australia Post 4State	australian-post-4state
Aztec	aztec
Codabar	codabar
Code 11	code11
Code 128	code128
Code 32	code32
Code 39	code39
Code 93	code93
DataBar 14	databar
DataBar Expanded	databar-expanded
DataBar Limited	databar-limited
DataMatrix	data-matrix
DotCode	dotcode
EAN13 / UPCA	ean13upca
EAN8	ean8
Five-Digit-Add-On	five-digit-add-on
French Post (La Poste)	french-post
IATA 2of5	iata2of5
Interleaved 2 of 5	itf
KIX	kix
LAPA 4SC	lapa4sc
Matrix 2of5	matrix2of5
MaxiCode	maxicode
MicroPDF417	micropdf417
Micro QR	microqr
MSI-Plessey	msi-plessey
PDF417	pdf417
QR Code	qr
Royal Mail 4State	rm4scc
Standard 2 of 5 (Code 25)	code25
Two-Digit-Add-On	two-digit-add-on
UPCE	upce
UPU 4State	upu-4state
USPS Intelligent Mail	usps-intelligent-mail

Symbology Settings

By default, all symbologies are disabled. To enable a symbology, it must be listed under the "symbologies" key. Symbologies can either be a dictionary, or an array of symbology names:

{
    "symbologies" :  [ "ean13upca", "ean8", "code128" ]
}

When using a dictionary, further symbology options can be specified, such as extensions to enable, used checksums etc.:

{
    "symbologies" :  {
        "code128" : true,
        "ean13upca" : { 
           "extensions" : ["remove_leading_upca_zero"]
        },
        "itf" : {
            "checksums" : [ "mod10" ]
        }
    }
}

The following options are currently supported:

• enabled: boolean indicating whether the symbology should be enabled. When using the dictionary form, enabled is automatically set to true.
• colorInvertedEnabled: boolean indicating whether color-inverted codes of that symbology should be decoded. Default is false.
• activeSymbolCounts: array of integers specifying the active symbol counts for the symbology. See sc_symbology_settings_set_active_symbol_counts for details.
• extensions: Extensions to be enabled for the symbology.
• checksums: List of optional checksums to use for the symbology.

Depending on the symbology, some of these properties are ignored. See Configure Barcode Symbologies for details.

Code Location and Search Area

To customize the search area and code location hints, you can use the codeLocation1d, codeLocation2d, searchArea and codeDirectionHint properties.

Search Area

To customize the search area, set the searchArea property by defining the rectangle with x, y, width, and height.

{ 
    "searchArea" : { 
        "x" : 0.0, "y" : 0.0, "width" : 1.0, "height" : 0.5 
    } 
}

Code Location

To customize code location 1d and code location 2d, use the codeLocation1d and codeLocation2d properties. They consist of a rectangle, the area, and a constraint.

{ 
    "codeLocation1d" : { 
        "area" : {"x" : 0.0, "y" : 0.0, "width" : 1.0, "height" : 0.5 },
        "constraint" : "restrict" // or "hint"
    } 
}

Constraint must either be "restrict", or "hint".

Code Direction Hint

To customize the code direction hint, use the codeDirectionHint property.

{ 
	"codeDirectionHint" : "left-to-right"
}

The code direction hint must either be "left-to-right", "right-to-left", "bottom-to-top", "top-to-bottom", "none", "vertical", or "horizontal".

Additional Properties

maxNumberOfCodesPerFrame sets the maximum number of codes per frame, see sc_barcode_scanner_settings_set_max_number_of_codes_per_frame(). codeDuplicateFilter sets the code duplicate filter, see sc_barcode_scanner_settings_set_code_duplicate_filter(). arucoDictionaryPreset sets the ArUco dictionary preset, see sc_aruco_dictionary_from_preset().