identicon.cr

Create github-style identicons

This is a straight port of Chris Branson's ruby_identicon, which is a Ruby implementation of go-identicon by Damian Gryski

Installation

Add this to your application's shard.yml:

dependencies:
  identicon:
    github: oneiros/identicon.cr

Usage

require "identicon"

Creating an identicon and saving to png

Identicon.create_and_save("Identicon", "identicon.png")

Creating an identicon and returning a binary string

blob = Identicon.create("Identicon")

# optional, save to a file
File.open("identicon.png", "wb") do |f|
  f << blob
end

Creating an identicon and returning in Base64 format

base64_identicon = Identicon.create_base64("Identicon")

to render this in HTML, pass the Base64 code into your template:

<img src='data:image/png;base64,<%= base64_identicon %>'>

Customising the identicon

The identicon can be customised by passing additional options

background_color:  (String, default "#00000000") the background color of the identicon in hex notation (e.g. "#ffffff" for white)
border_size:  (Int32, default 35) the size in pixels to leave as an empty border around the identicon image
grid_size:    (Int32, default 7)  the number of rows and columns in the identicon, minimum 4, maximum 9
square_size:  (Int32, default 50) the size in pixels of each square that makes up the identicon
key:          (String) a 16 byte key used by siphash when calculating the hash value (see note below)

Varying the key ensures uniqueness of an identicon for a given title, it is assumed desirable for different applications to use a different key.

Example

blob = Identicon.create("identicons are great!", grid_size: 5, square_size: 70, background_color: "#f0f0f0ff", key: "1234567890123456")
File.open("tmp/test_identicon.png", "wb") { |f| f << blob }