Package 'qrcode'

Add a logo to a QR code

Description

First generate a qr_code with a higher ecl level. Then add the logo. The maximum area of logo depends on the difference in ecl level between the version with and without logo. The size of the logo is further restricted by its image ratio. We shrink very wide or tall logos to make sure it still fits on the logo.

Usage

add_logo(
  code,
  logo,
  ecl = c("L", "M", "Q", "H"),
  hjust = c("c", "l", "r"),
  vjust = c("c", "b", "t")
)

Arguments

code	A qr_code object
logo	the path to a logo image file. Must be either png, svg or jpeg format.
ecl	the required error correction level for the QR code after overlaying the logo. Must be lower than the ecl in the code. Defaults to "L". The difference between the ecl set here and the ecl in code determines the maximum area of the logo. For the largest logo, generate code with ecl = "H" and add the logo with ecl = "L".
hjust	Horizontal position of the logo. The default of "c" indicates the centre of the QR code. Use "r" to align the right side of the logo with the right side of the QR code. Use "l" to align the left side of the logo with the right side of the two vertical finder patterns.
vjust	Vertical position of the logo. The default of "c" indicates the centre of the QR code.. Use "b" to align the bottom of the logo with the bottom of the QR code. Use "t" to align the top of the logo with the bottom side of the two horizontal finder patterns.

---

Convert a bits object into a character string

Description

Convert a bits object into a character string

Usage

## S3 method for class 'bits'
as.character(x, ...)

Arguments

x	the bits object
...	currently ignore

Author(s)

Thierry Onkelinx

See Also

Other bits: bits(), bits2int(), c.bits(), print.bits()

Examples

z <- bits(c(FALSE, TRUE, TRUE, FALSE))
z
as.character(z)

---

Create a bits object

Description

Converts a logical vector into a bits object. This remains a logical vector. The main difference is that is printed as a 0 and 1 bit string rather than a FALSE and TRUE vector

Usage

bits(x)

Arguments

x	a logical vector

Author(s)

Thierry Onkelinx

See Also

Other bits: as.character.bits(), bits2int(), c.bits(), print.bits()

Examples

z <- bits(c(FALSE, TRUE))
z
str(z)

---

Convert a bits object to an integer and vice versa

Description

Convert a bits object to an integer and vice versa

Usage

bits2int(x)

int2bits(i, n_bit = 16)

Arguments

x	the bits object
i	the integer
n_bit	the number of bits

Author(s)

Thierry Onkelinx

See Also

Other bits: as.character.bits(), bits(), c.bits(), print.bits()

Examples

z <- bits(c(FALSE, TRUE, TRUE, FALSE))
z
y <- bits2int(z)
y
int2bits(y)
int2bits(y, 4)

---

Combine bits

Description

The result inherits arguments from the first element.

Usage

## S3 method for class 'bits'
c(...)

Arguments

...	the bits to concatenate

Author(s)

Thierry Onkelinx

See Also

Other bits: as.character.bits(), bits(), bits2int(), print.bits()

Examples

z <- bits(c(FALSE, TRUE))
z
c(z, z, rev(z))

---

Extract coordinates from a QR code object.

Description

Selects the dark elements from the qr_code object and returns their coordinates. This can be useful when you want to create a QR code with a custom style.

Usage

coordinates(x)

Arguments

x	the qr_code object.

Value

A data.frame with the column and row number of the dark elements.

Author(s)

Thierry Onkelinx

See Also

Other qr: generate_svg(), plot.qr_code(), print.qr_code(), qr_code(), qr_event(), qr_location(), qr_sepa(), qr_wifi()

Examples

x <- qr_code("test")
plot(x)
head(coordinates(x))
plot(coordinates(x), pch = 19, cex = 2, asp = 1)

---

Generate the QR code as an svg file

Description

Create the QR code using qr_code() and save it as an svg file.

Usage

generate_svg(
  qrcode,
  filename,
  size = 300,
  foreground = "black",
  background = "white",
  show = interactive(),
  ...
)

## Default S3 method:
generate_svg(
  qrcode,
  filename,
  size = 300,
  foreground = "black",
  background = "white",
  show = interactive(),
  ...
)

## S3 method for class 'qr_code'
generate_svg(
  qrcode,
  filename,
  size = 300,
  foreground = "black",
  background = "white",
  show = interactive(),
  ...
)

## S3 method for class 'qr_wifi'
generate_svg(
  qrcode,
  filename,
  size = 300,
  foreground = "black",
  background = "white",
  show = interactive(),
  ...,
  fontsize = 15
)

## S3 method for class 'qr_logo'
generate_svg(
  qrcode,
  filename,
  size = 300,
  foreground = "black",
  background = "white",
  show = interactive(),
  ...
)

Arguments

qrcode	a qr_code object as generated by qr_code.
filename	Where to store the QR code as svg file. Silently overwrites existing files. Tries to create the path, when it doesn't exist.
size	width of the svg file in pixels. Defaults to 300.
foreground	Stroke and fill colour for the foreground. Use a valid CSS colour. Defaults to "black".
background	Fill colour for the background. Use a valid CSS colour. Defaults to "white".
show	Open the file after creating it. Defaults to TRUE on interactive() sessions, otherwise FALSE.
...	Currently ignored.
fontsize	The size of the font in pixels.

Value

invisible NULL

Author(s)

Thierry Onkelinx

See Also

Other qr: coordinates(), plot.qr_code(), print.qr_code(), qr_code(), qr_event(), qr_location(), qr_sepa(), qr_wifi()

Examples

code <- qr_code("HELLO WORLD")
generate_svg(
  qrcode = code, filename = tempfile(fileext = ".svg"), show = FALSE
)

---

Plot the QR code This function plots to QR code to the open device.

Description

Plot the QR code This function plots to QR code to the open device.

Usage

## S3 method for class 'qr_code'
plot(x, col = c("white", "black"), y, ...)

## S3 method for class 'qr_logo'
plot(x, col = c("white", "black"), y, ...)

Arguments

x	the qr_code object
col	Define the colours. The first element refers to FALSE and the second TRUE. Defaults to c("white", "black").
y	currently ignored
...	currently ignored

Author(s)

Thierry Onkelinx

See Also

opencv::ocv_qr_detect() for reading QR codes.

Other qr: coordinates(), generate_svg(), print.qr_code(), qr_code(), qr_event(), qr_location(), qr_sepa(), qr_wifi()

Other qr: coordinates(), generate_svg(), print.qr_code(), qr_code(), qr_event(), qr_location(), qr_sepa(), qr_wifi()

Examples

qr <- qr_code("HELLO WORLD")
plot(qr)

# Test the QR code with the opencv package
if (requireNamespace("opencv")) {
  png("test.png")
  plot(qr)
  dev.off()
  opencv::ocv_qr_detect(opencv::ocv_read('test.png'))
  unlink("test.png")
}

---

Print a bits vector Display the logical vector as a bit string where FALSE is shown as 0 and TRUE as 1.

Description

Print a bits vector Display the logical vector as a bit string where FALSE is shown as 0 and TRUE as 1.

Usage

## S3 method for class 'bits'
print(x, ...)

Arguments

x	the object to print
...	currently ignored

Author(s)

Thierry Onkelinx

See Also

Other bits: as.character.bits(), bits(), bits2int(), c.bits()

Examples

z <- bits(c(FALSE, TRUE))
print(z)

---

Print the qr_code object

Description

Please use plot(x) for a better quality image

Usage

## S3 method for class 'qr_code'
print(x, ...)

Arguments

x	the qr_code object
...	currently ignored

Author(s)

Thierry Onkelinx

See Also

Other qr: coordinates(), generate_svg(), plot.qr_code(), qr_code(), qr_event(), qr_location(), qr_sepa(), qr_wifi()

Examples

qr_code("HELLO WORLD")

---

Generate the QR code

Description

A QR code is a two-dimensional barcode developed by the Denso Wave company.

Usage

qr_code(x, ecl = c("L", "M", "Q", "H"))

Arguments

x	the input string
ecl	the required error correction level. Available options are "L" (7%), "M" (15%), "Q" (25%) and "H" (30%). Defaults to "L".

Value

The QR code as a logical matrix with "qr_code" class.

Author(s)

Thierry Onkelinx

See Also

Other qr: coordinates(), generate_svg(), plot.qr_code(), print.qr_code(), qr_event(), qr_location(), qr_sepa(), qr_wifi()

Examples

qr_code("https://www.r-project.org")
qr <- qr_code("https://cran.r-project.org/package=qrcode", ecl = "M")
qr
plot(qr)
# the qr_code object is a logical matrix
str(qr)
qr[1:10, 1:10]

---

Create the bit encoding

Description

The message converted into a bit string.

Usage

qr_encode(x, ecl = c("L", "M", "Q", "H"))

Arguments

x	the input string
ecl	the required error correction level. Available options are "L" (7%), "M" (15%), "Q" (25%) and "H" (30%). Defaults to "L".

Author(s)

Thierry Onkelinx

See Also

Other internal: qr_error(), qr_matrix(), qr_mode(), qr_version()

Examples

qr_encode("HELLO WORLD")

---

Create the message and error code bit string

Description

The function returns a bit string containing the message.

Usage

qr_error(x, ecl = c("L", "M", "Q", "H"))

Arguments

x	the input string
ecl	the required error correction level. Available options are "L" (7%), "M" (15%), "Q" (25%) and "H" (30%). Defaults to "L".

Value

The message as a bits() object.

Author(s)

Thierry Onkelinx

See Also

Other internal: qr_encode(), qr_matrix(), qr_mode(), qr_version()

Examples

qr_error("HELLO WORLD")

---

Generate a QR code for an event

Description

Generate a QR code for an event

Usage

qr_event(start, end, title, ..., ecl = c("L", "M", "Q", "H"))

Arguments

start	the required start time as POSIXct.
end	the required end time as POSIXct.
title	the required title of the event.
...	optional arguments as defined in the details.
ecl	the required error correction level. Available options are "L" (7%), "M" (15%), "Q" (25%) and "H" (30%). Defaults to "L".

Details

Optional arguments. Other arguments are silently ignored.

• description

• location

• organiser

• url

See Also

Other qr: coordinates(), generate_svg(), plot.qr_code(), print.qr_code(), qr_code(), qr_location(), qr_sepa(), qr_wifi()

---

Create a QR code for a location

Description

Create a QR code for a location

Usage

qr_location(latitude, longitude, ecl = c("L", "M", "Q", "H"))

Arguments

latitude	the latitude of the location.
longitude	the longitude of the location.
ecl	the required error correction level. Available options are "L" (7%), "M" (15%), "Q" (25%) and "H" (30%). Defaults to "L".

See Also

Other qr: coordinates(), generate_svg(), plot.qr_code(), print.qr_code(), qr_code(), qr_event(), qr_sepa(), qr_wifi()

Examples

qr_location(50.8449861, 4.3499932) |>
  plot()

---

Prepare matrices with default patterns and unmasked data A list with a matrix containing the default patterns (finder pattern, timing pattern, separators, alignment pattern and dark module), the unmask data pattern and the version.

Description

Prepare matrices with default patterns and unmasked data A list with a matrix containing the default patterns (finder pattern, timing pattern, separators, alignment pattern and dark module), the unmask data pattern and the version.

Usage

qr_matrix(x, ecl = c("L", "M", "Q", "H"))

Arguments

x	the input string
ecl	the required error correction level. Available options are "L" (7%), "M" (15%), "Q" (25%) and "H" (30%). Defaults to "L".

Author(s)

Thierry Onkelinx

See Also

Other internal: qr_encode(), qr_error(), qr_mode(), qr_version()

Examples

qr_matrix("HELLO WORLD")

---

Determine the required mode

Description

The current implementation handles three modes: numeric, alphanumeric and byte. Kanji is currently not supported. Please contact the maintainer if you need it. Numeric: only digits from 0 to 9 Alphanumeric: all numeric characters, upper case LETTERS, and the characters " " (space), "$", "%", "*", "+", "-", ".", "/" and ":" Byte: All characters from the Latin 1 (ISO 8859-1) character set. Input strings with an other encoding are converted into Latin 1. The function return an error if such conversion fails.

Usage

qr_mode(x)

Arguments

x	the input string

Value

a character indicating the mode

Author(s)

Thierry Onkelinx

See Also

Other internal: qr_encode(), qr_error(), qr_matrix(), qr_version()

Examples

qr_mode("0123")
qr_mode("A")
qr_mode("a")

---

Generate a QR code for a SEPA payment

Description

Generate a QR code for a SEPA payment

Usage

qr_sepa(
  iban,
  beneficiary,
  amount,
  unstructured_reference = "",
  bic = "",
  purpose = "",
  structured_reference = ""
)

Arguments

iban	the IBAN of the beneficiary.
beneficiary	the name of the beneficiary.
amount	the amount to transfer. Must be in EUR.
unstructured_reference	the unstructured reference. The unstructured reference is a string of maximum 140 characters.
bic	the BIC of the beneficiary.
purpose	the purpose of the payment.
structured_reference	the structured reference.

See Also

Other qr: coordinates(), generate_svg(), plot.qr_code(), print.qr_code(), qr_code(), qr_event(), qr_location(), qr_wifi()

Examples

qr_sepa(
  iban = "GB33BUKB20201555555555", beneficiary = "John Doe",
  amount = 100, unstructured_reference = "Test payment"
) |>
  plot()

---

Create a QR code for a vCard

Description

Create a QR code for a vCard

Usage

qr_vcard(
  given,
  family,
  address,
  email,
  telephone,
  organisation,
  job_title,
  url,
  gender,
  logo,
  photo,
  middle = character(0),
  prefix = character(0),
  suffix = character(0),
  ecl = c("L", "M", "Q", "H"),
  ...
)

Arguments

given	The given name.
family	The family name.
address	In case of a single address, a named character vector with the following elements: street_nr, city, region, postal_code and country. In case of multiple addresses, a named list of named character vectors. The names of the list are used as the type of the address.
email	Optionally one or more email addresses. The names of the vector are used as the type of the email address.
telephone	Optionally one of more telephone numbers. The names of the vector are used as the type of the telephone number.
organisation	Optionally the name of your organisation and team within the organisation.
job_title	Optionally the job title of the person.
url	Optionally one or more URLs. The names of the vector are used as the type of the URL.
gender	Optionally a string describing the gender of the person.
logo	Optionally a URL to a logo.
photo	Optionally a URL to a photo.
middle	Optionally one or more middle names.
prefix	Optionally one or more prefixes.
suffix	Optionally one or more suffixes.
ecl	the required error correction level. Available options are "L" (7%), "M" (15%), "Q" (25%) and "H" (30%). Defaults to "L".
...	Additional arguments are silently ignored.

---

Determine the required version Returns a list with the version, error correction level and mode. The bit string encodes mode and the length of the input string.

Description

Determine the required version Returns a list with the version, error correction level and mode. The bit string encodes mode and the length of the input string.

Usage

qr_version(x, ecl = c("L", "M", "Q", "H"))

Arguments

x	the input string
ecl	the required error correction level. Available options are "L" (7%), "M" (15%), "Q" (25%) and "H" (30%). Defaults to "L".

Author(s)

Thierry Onkelinx

See Also

Other internal: qr_encode(), qr_error(), qr_matrix(), qr_mode()

Examples

qr_version("HELLO WORLD")
qr_version("hello world", ecl = "H")

---

Generate QR code with wifi login information

Description

Generate QR code with wifi login information

Usage

qr_wifi(
  ssid,
  encryption = c("WPA", "WEP", ""),
  key = "",
  hidden = FALSE,
  ecl = c("L", "M", "Q", "H")
)

Arguments

ssid	The SSID of the network.
encryption	The encryption standard. Options are "WPA", "WEP" and "". The latter implies no encryption. Defaults to "WPA".
key	The key for the encryption.
hidden	Use FALSE for a visible SSID. Use TRUE for a hidden SSID. Defaults to FALSE.
ecl	the required error correction level. Available options are "L" (7%), "M" (15%), "Q" (25%) and "H" (30%). Defaults to "L".

See Also

Other qr: coordinates(), generate_svg(), plot.qr_code(), print.qr_code(), qr_code(), qr_event(), qr_location(), qr_sepa()

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