QRgen - A QR generation library

QRgen is a QR generation library fully written in Nim that only uses a small amount of pure-nim stdlib modules.

Prerequisites

nim --version >= 1.6.0

Installation

nimble install qrgen

Features

• Supports all QR versions: from 1 to 40.
• Supports all EC (Error Correction) levels: L, M, Q and H.
• Supports numeric mode, alphanumeric mode and byte mode.
• Supports printing a QR code on your terminal via standard output.
• Supports printing a QR code to SVG, with custom colors, using circles, embedding SVG logos etc.
• Supports rendering a QR code to pixie's Image, with the same features as SVG (but can embed more image formats). Image can be exported to various formats, like PNG.

Usage

import QRgen
let myQR = newQR("https://github.com/aruZeta/QRgen")

Terminal

myQR.printTerminal

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SVG

Generic QR with white background and black foreground

myQR.printSvg

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Changing the background and foreground colors

myQR.printSvg("#1d2021","#98971a")

"#1d2021" sets the "light" or "background" color. "#98971a" sets the "dark" or "foreground" color.

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Making the alignment patterns rounded

myQR.printSvg("#1d2021","#98971a",60)

60 sets the alignment patterns' roundness to 60%.

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Making the modules rounded

myQR.printSvg("#1d2021","#98971a",100,100)

The first 100 sets the alignment patterns' roundness to 100% while the second 100 sets the module's roundness to 100% too.

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Changing the separation of the modules

myQR.printSvg("#1d2021","#98971a",100,100,25)

The last 25 sets the module's separation to 25%.

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Embedding another SVG in the generated QR code

Here we will need the highest EC level, for a better result (bigger logo):

let myQR = newQR("https://github.com/aruZeta/QRgen", ecLevel=qrECH)

myQR.printSvg("#1d2021","#98971a",100,100,25,svgImg=readFile("QRgen-logo.svg"))

svgImg adds an SVG image embed in the center of generated QR code, so we can pass it the contents of an SVG file, here a logo, and the result as you can see is the actual QRgen logo.

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Since the generated SVGs have css classes, we can do stuff like this:

https://user-images.githubusercontent.com/68018085/190470749-66090814-08fe-45b5-881d-a96b272374be.mp4

https://user-images.githubusercontent.com/68018085/190470760-8a5b5a30-5812-4777-8e05-8d2b250a9113.mp4

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PNG

Note: The PNG renderer is not exported with QRgen since it depends on pixie (check pixie here). To use it you will need to add this import:

import QRgen/renderer

And obviously install and import pixie too.

Note: renderImg returns an Image which to the save as let's say a PNG, you will need to do:

let myQRImg = renderImg(...)
writeFile(myQRImg, "path/to/save/it.png")

You can check pixie to learn about more formats you can save an Image as.

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Generic QR with white background and black foreground

myQR.renderImg

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Changing the background and foreground colors

myQR.renderImg("#1d2021","#98971a")

"#1d2021" sets the "light" or "background" color. "#98971a" sets the "dark" or "foreground" color.

---

Making the alignment patterns rounded

myQR.renderImg("#1d2021","#98971a",60)

60 sets the alignment patterns' roundness to 60%.

---

Making the modules rounded

myQR.renderImg("#1d2021","#98971a",100,100)

The first 100 sets the alignment patterns' roundness to 100% while the second 100 sets the module's roundness to 100% too.

---

Changing the separation of the modules

myQR.renderImg("#1d2021","#98971a",100,100,25)

The last 25 sets the module's separation to 25%.

---

Embedding another PNG in the generated QR code

Here we will need the highest EC level, for a better result (bigger logo):

let myQR = newQR("https://github.com/aruZeta/QRgen", ecLevel=qrECH)

myQR.renderImg("#1d2021","#98971a",100,100,25,img=readImage("QRgen-logo.png"))

img embeds an Image in the center of the generated QR code, so we can use pixie's readImage to read a PNG file, here a logo, and the result as you can see is the actual QRgen logo.

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Note that you can change the resolution of the generated image by setting pixels to a higher value, by default it's set to 512 pixels (both width and height).

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Documentation

Check the docs to know more about the main API.

More examples

Check my simple terminal app's code, QRterm, which uses this library to generate QR codes from your terminal, and also it's logo generator.

Also check this repo's logo and its README images generator.

License

Distributed under the MIT License. See LICENSE for more information.