raco pkg install simple-qr
(qr-write
[data (string?)]
[output_file_path (path-string?)]
[#:mode mode string? "B"]
[#:error_level error_level string? "H"]
[#:module_width module_width natural? 5]
[#:color color (cons/c string? string?) '("black" . "white")]
[#:express? express? boolean? #f]
[#:express_path express_path path-string? "imgfile + '.write.express'"]
[#:output_type output_type (or/c 'png 'svg)]
)
void?output qr code image to file.
color's form is '(front_color . background_color).
use color "transparent" to set transparent(background).
if output_type is png, can use @racket[color-database<%>], but hex color is all available in all formats, recommended.
(qr-read
[image_file_path (path-string?)]
[#:express? express? boolean? #f]
[#:express_path express_path path-string? "imgfile + '.read.express'"]
)
string?read qr code image's content, if failed, return "".
#lang racket
(require simple-qr)
;; block's default width is 5
(qr-write "https://github.com/simmone" "normal.png")
(qr-write "https://github.com/simmone" "normal_color.png" #:color '("#ffbb33" . "#0d47a1"))
(qr-write "https://github.com/simmone" "normal_trans.png" #:color '("#9933CC" . "transparent"))
(qr-write "https://github.com/simmone" "small.png" #:module_width 2)
(qr-write "https://github.com/simmone" "large.png" #:module_width 10)
(printf "~a\n~a\n~a\n"
(qr-read "normal.png")
(qr-read "small.png")
(qr-read "large.png"))
(printf "~a\n" (qr-read "damaged.png"))
(qr-write "https://github.com/simmone" "normal.svg" #:output_type 'svg)
(qr-write "https://github.com/simmone" "normal_color.svg" #:color '("#ffbb33" . "#0d47a1") #:output_type 'svg)
(qr-write "https://github.com/simmone" "normal_trans.svg" #:color '("#9933CC" . "transparent") #:output_type 'svg)
(qr-write "https://github.com/simmone" "normal.png")
(qr-write "https://github.com/simmone" "normal_color.png" #:color '("#ffbb33" . "#0d47a1"))
)
(qr-write "https://github.com/simmone" "normal_trans.png" #:color '("#9933CC" . "transparent"))
(qr-write "https://github.com/simmone" "small.png" #:module_width 2)
(qr-write "https://github.com/simmone" "large.png" #:module_width 10)
(qr-write "https://github.com/simmone" "normal.svg" #:output_type 'svg)
(qr-write "https://github.com/simmone" "normal_color.svg" #:color '("#ffbb33" . "#0d47a1") #:output_type 'svg)
(qr-write "https://github.com/simmone" "normal_trans.svg" #:color '("#9933CC" . "transparent") #:output_type 'svg)
(printf "~a\n" (qr-read "damaged.png"))
If you want to see the each step of read or write a qr code, can set #:express? to true.
Default will create folder .read.express for qr-read or .write.express for qr-write.
You can use #:express_path to specify another folder name.
Warning: express will generate a set of scribble files, it's very slow, debug usage only.
Then into the express folder, "scribble --htmls report.scrbl" to generate a detail report.