Worldize allows to draw world countries coloured on base of some numeric value for each country.

Adds VIPS support to CarrierWave

Fastlane plugin for release automation

Locally generate two-caption 'Advice Dog'-style meme images

A command-line tool for creating animated GIFs.

Jcrop plugin for ActiveAdmin, enable image cropping solution on image fields

Automatic Retina Image Handling

Calculate Dhash on images

Collection of tools that make printing of plain text and images to one or many serial thermal printers easy. USB, serial (RS232) and TCP/IP printers are supported. Escper is useful for Ruby based Point of Sale systems that want to print receipts or tickets, but also suitable for stand-alone applications.

This gem providers a small server to allow linking to arbitrarily-sized placeholder images.

Retrieves palette of main colors, merging similar colors using Lab color space.

This Jekyll plugin makes it very easy to send larger images to devices with high pixel densities. The plugin adds an `image_tag` Liquid tag that can be used like this: {% image_tag src="/image.png" width="100" %}

Simple, pure-ruby library for making pretty Wordle-like clouds. It uses RMagick as graphic backend.

Turn an image into an X,Y tile set for use with JS mapping libraries

An extension of Prawn that improves the performance when embedding PNG images containing an alpha channel

Syntax tree generator made with Ruby

Skyline is an extremely flexible and expandable open source content management system. Its feature rich interface allows for fast and intuitive management of websites.

A sprite generation tool

Turn an image into an X,Y tile set for use with JS mapping libraries

A barcode and QR code library that works with regular Ruby (not just JRuby). This gem comes bundled with ZXing C++ (zxing-cpp) and interfaces with it using FFI. As such this gem works with most major Ruby distributions.