qr-image-color

qr-image-color

This is a fork of awesome alexeyten's qr-image generator.

This fork adds support for custom colors and non-transparent backgrounds in SVG, EPS and PDF files, as well as custom colors and transparent backgrounds in PNG files.

For complete description of qr-image please visit original repo.

Overview

• NEW in this fork: supports custom colors for code and background, as well as transparent/opaque backgrounds.

Releases

Installing

npm install qr-image-color

Color Data Types

You can pass the color and background options in several ways:

Data Type	Color Model
string	RGB (as #rrggbb, with or without leading #; as #rgb, (short notation); or as CSS color name
number	Gray in range 0.0…1.0 (0.0=black, 1.0=white)
Array(3) of numbers	RGB (Components in range 0…255)
Array(4) of numbers	CMYK (Components in range 0.0…1.0)

Color Model Support Overview

	PDF	EPS	SVG	PNG
Gray	✓	✓	⤑ Hex	⤑ RGB[1]
RGB	✓	✓	⤑ Hex	✓ [1]
CMYK	✓	✓	⤑ Hex[2]	⤑ RGB[2]
Hex Color	⤑ RGB	⤑ RGB	✓	⤑ RGB

[1] NOTE: Generated QR-codes are Indexed Color PNG files. See note about customize option below.

[2] No attempt has been made to use calibrated conversion from CMYK to RGB, so if you use CMYK colors in SVG or PNG, do not expect prepress-quality conversion. If you need precise CMYK color control, use PDF or EPS files, since they have native CMYK support.

Usage

Examples:

var qr = require('qr-image-color');

var qr_svg = qr.image('I love Default QR (with black/transparent)!', { type: 'svg' });
qr_svg.pipe(require('fs').createWriteStream('i_love_qr.svg'));

// use foreground color (CMYK) and no background;
var pdf_string = qr.imageSync('I love Color QR!', { type: 'pdf', color: [0.7, 0, 0, 1]  });

// use foreground color (RGB) and light gray (10% Black) background;
var eps_string = qr.imageSync('I love Color QR!', { type: 'eps', color: [128, 0, 64], background: [0,0,0,0.1], transparent: false });

// png with purple color and transparent background;
var png_string = qr.imageSync('I love transparent QR in PNG!', { type: 'png', color: "purple", transparent: true });

Example of transparent PNG with color "purple"

More examples

Methods

• qr.image(text, [ec_level | options]) — Readable stream with image data;
• qr.imageSync(text, [ec_level | options]) — string with image data. (Buffer for png);
• qr.svgObject(text, [ec_level | options]) — object with SVG path and size;
• qr.matrix(text, [ec_level]) — 2D array.

Options

• text — text to encode;
• ec_level — error correction level. One of L, M, Q, H. Default M.
• options — image options object:
  • ec_level — default M.
  • type — image type. Possible values png (default), svg, pdf and eps.
  • size (png and svg only) — size of one module in pixels. Default 5 for png and undefined for svg.
  • margin — white space around QR image in modules. Default 4 for png and 1 for others.
  • customize (only png) — function to customize qr bitmap before encoding to PNG. We are now using Index Color PNG instead of grayscale, so using this option will behave different
  • parse_url (experimental, default false) — try to optimize QR-code for URLs.
• NEW options
  • transparent (boolean) For PNG, default is false, for vector formats default is true. I choose these defaults to keep the behaviour as it was earlier, in case transparent option is not explicitly set. If set to true, then background parameter is ignored. If set to false, and no background is specified, background defaults to white.
  • color color for code blocks. If omitted, default is pure black.
  • background color for code background. If omitted, default is transparent.

TODO

• Tests;