README

= ImageRuby - flexible ruby gem for image processing

ImageRuby is a gem for image processing written in pure ruby, this makes the library very portable and easy to install

Also, the gem was desgined to accept extensions like:
 * new format decoders made from scratch (Ruby or C)
 * new format decoders based on existent C libraries like libpng, libbmp, etc...
 * new image operations (Ruby or C)
 * re-implementations of parts in C to improve performance on environments where it is possible

== Installation

=== Gem installation

sudo gem install imageruby

== Documentation

Full API documentation can be found on:
http://tario.github.com/imageruby/doc/

== Examples

NOTE: Examples loads and saves bitmap files, imageruby-bmp gem must be installed in order
to get the examples work

=== Create and save a black image

  require "rubygems"
  require "imageruby"

  include ImageRuby

  #  creates an image of 150x150 pixels filled with black
  image = ImageRuby::Image.new(150,150, Color.black)

  begin
  # this only work if imageruby-bmp gem is installed
  image.save("black.bmp", :bmp)
  rescue
    print "Error while trying to save, you must install imageruby-bmp gem"
  end

=== Create an image with vertical stripes filled with default named colors

  require "rubygems"
  require "imageruby"

  include ImageRuby

  print "list of named colors:\n"
  print "--------------------------\n"

  colors = Array.new

  Color.named_colors.each do |name, color|
	print "#{name}: #{color.inspect}\n"
	colors << color
  end

  image = Image.new( colors.count * 32, 512)

  x = 0
  colors.each do |color|
  image[x..x+31, 0..511] = Image.new(32,512,color)
  x = x + 32
  end

  image.save("colors.bmp", :bmp)

=== Gradient using block parameter

  require "rubygems"
  require "imageruby"

  include ImageRuby

  gradient_images = Array.new

  gradient_images << Image.new(64,64) {|x,y| 
    Color.from_rgb(x*4,y*4,0) 
  }

  gradient_images << Image.new(64,64) {|x,y| 
    Color.from_rgb(0,x*4,y*4) 
  }

  gradient_images << Image.new(64,64) {|x,y| 
    Color.from_rgb(y*4,0,x*4) 
  }

  (0..gradient_images.count-1).each do |i|
	gradient_images[i].save("gradient#{i}.bmp", :bmp)
  end

  all_gradient = Image.new(96*gradient_images.count, 96)

  (0..gradient_images.count-1).each do |i|
	all_gradient.draw!(i*96+16, 16, gradient_images[i])
  end

  all_gradient.save("gradients.bmp", :bmp)


=== Draw with mask

  require "rubygems"
  require "imageruby"

  include ImageRuby

  colors = Image.from_file("colors.bmp")
  gradients = Image.from_file("gradients.bmp")

  without_mask = colors.draw(128,192,gradients)
  without_mask.save("without_mask.bmp", :bmp)

  with_mask = colors.draw(128,192,gradients.mask(Color.black))
  with_mask.save("with_mask.bmp", :bmp)

=== Draw with transparency effects

  require "rubygems"
  require "imageruby"

  include ImageRuby

  colors = Image.from_file("colors.bmp")
  gradients = Image.from_file("gradients.bmp")

  transparent_black = Color.black
  transparent_black.a = 128


  colors.draw(128,192,gradients.color_replace(Color.black, transparent_black)).save("sample1.bmp", :bmp)

  half_transparent = gradients.map_pixel{ |x,y,c|
	c.a = 128 if x >144
	c
  }
  colors.draw(128,192,half_transparent).save("sample2.bmp", :bmp)



== Copying

Copyright (c) 2011 Dario Seminara, released under the GPL License (see LICENSE)