Class: ImageVoodoo

Inherits:
Object
  • Object
show all
Includes:
Shapes, Java
Defined in:
lib/image_voodoo.rb,
lib/image_voodoo/awt.rb,
lib/image_voodoo/gae.rb,
lib/image_voodoo/version.rb,
lib/image_voodoo/awt/shapes.rb

Overview

ImageVoodoo

Description

ImageVoodoo is an ImageScience-API-compatible image manipulation library for JRuby.

Examples

Simple block-based examples

ImageVoodoo.with_image(ARGV[0]) do |img|
  img.cropped_thumbnail(100) { |img2| img2.save "CTH.jpg" }
  img.with_crop(100, 200, 400, 600) { |img2| img2.save "CR.jpg" }
  img.thumbnail(50) { |img2| img2.save "TH.jpg" }
  img.resize(100, 150) do |img2|
    img2.save "HEH.jpg"
    img2.save "HEH.png"
  end
end

Non-block return (not image_science compatible)

img = ImageVoodoo.with_image(ARGV) negative_img = img.negative

Defined Under Namespace

Modules: Shapes Classes: JImagePanel, WindowClosed

Constant Summary collapse

JFile = 
java.io.File
ImageService = 
ImagesServiceFactory.images_service
VERSION = 
"0.8.7"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Shapes

#as_color, #rect, #rect_rounded, #square, #square_rounded

Constructor Details

#initialize(src, format = nil) ⇒ ImageVoodoo

Returns a new instance of ImageVoodoo.



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# File 'lib/image_voodoo.rb', line 47

def initialize(src, format=nil)
  @src = src
  @format = format
  @quality = nil # nil means no specific quality ever specified
end

Instance Attribute Details

#quality(amount) ⇒ Object

Set quality you want resulting image to be once you save or extract bytes for the image. Note: This will only work for lossy image formats like PNG of JPEG. For others it will be ignored.



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# File 'lib/image_voodoo.rb', line 141

def quality
  @quality
end

Class Method Details

.canvas(width, height, rgb = '000000') ⇒ Object

AWT Create an image of width x height filled with a single color.



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# File 'lib/image_voodoo/awt.rb', line 134

def self.canvas(width, height, rgb='000000')
  image = ImageVoodoo.new(BufferedImage.new(width, height, ARGB))
  image.rect(0, 0, width, height, rgb)
end

.from_url(source) ⇒ Object

TODO: Figure out how to determine whether source has alpha or not Experimental: Read an image from the url source and yield/return that image.



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# File 'lib/image_voodoo/awt.rb', line 117

def self.from_url(source)
  url = java.net.URL.new(source)
  image = java.awt.Toolkit.default_toolkit.create_image(url)
  tracker = java.awt.MediaTracker.new(java.awt.Label.new(""))
  tracker.addImage(image, 0);
  tracker.waitForID(0)
  target = paint(BufferedImage.new(image.width, image.height, RGB)) do |g|
    g.draw_image image, 0, 0, nil
  end
  block_given? ? yield(target) : target
rescue java.io.IOException, java.net.MalformedURLException
  raise ArgumentError.new "Trouble retrieving image: #{$!.message}"
end

.guard(&block) ⇒ Object

*_impl providers only need provide the implementation if it can support it. Otherwise, this method will detect that the method is missing.



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# File 'lib/image_voodoo.rb', line 236

def self.guard(&block)
  begin
    return block.call
  rescue NoMethodError => e
    "Unimplemented Feature: #{e}"
  end
end

.with_bytes(bytes) ⇒ Object Also known as: with_image_from_memory

A top-level image loader reads bytes and then yields/returns the image.



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# File 'lib/image_voodoo.rb', line 220

def self.with_bytes(bytes)
  bytes = bytes.to_java_bytes if String === bytes
  image = guard { with_bytes_impl(bytes) }
  block_given? ? yield(image) : image
end

.with_image(path) ⇒ Object

A top-level image loader opens path and then yields/returns the image.

Raises:

  • (ArgumentError) 


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# File 'lib/image_voodoo.rb', line 210

def self.with_image(path)
  raise ArgumentError, "file does not exist" unless File.file?(path)
  image = guard { with_image_impl(JFile.new(path)) }
  image && block_given? ? yield(image) : image
end

Instance Method Details

#add_border(options = {}) ⇒ Object

FIXME: Move and rewrite in terms of new shape

AWT (experimental) Add a border to the image and yield/return a new image. The following options are supported:

- width: How thick is the border (default: 3)
- color: Which color is the border (in rrggbb hex value)
- style: etched, raised, plain (default: plain)



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# File 'lib/image_voodoo/awt.rb', line 36

def add_border(options = {})
  border_width = options[:width].to_i || 2
  color = hex_to_color(options[:color]) || hex_to_color("000000")
  style = options[:style]
  style = nil if style.to_sym == :plain
  new_width, new_height = width + 2*border_width, height + 2*border_width
  target = paint(BufferedImage.new(new_width, new_height, color_type)) do |g|
    g.color = color
    if style
      raised = style.to_sym == :raised ? true : false
      g.fill3DRect(0, 0, new_width, new_height, raised)
    else
      g.fill_rect(0, 0, new_width, new_height)
    end
    g.draw_image(@src, nil, border_width, border_width)
  end
  block_given? ? yield(target) : target
end

#adjust_brightness(scale, offset) ⇒ Object

Adjusts the brightness of each pixel in image by the following formula: new_pixel = pixel * scale + offset



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# File 'lib/image_voodoo.rb', line 58

def adjust_brightness(scale, offset)
  image = guard { adjust_brightness_impl(scale, offset) }
  block_given? ? yield(image) : image
end

#alpha(rgb) ⇒ Object

Converts rgb hex color value to an alpha value an yields/returns the new image.



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# File 'lib/image_voodoo.rb', line 68

def alpha(rgb)
  target = guard { alpha_impl(rgb) }
  block_given? ? yield(target) : target
end

#bytes(format) ⇒ Object

Get current image bytes as a String using provided format. Format parameter is the informal name of an image type - for instance, “bmp” or “jpg”. If the backend is AWT the types available are listed in javax.imageio.ImageIO.getWriterFormatNames()



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# File 'lib/image_voodoo.rb', line 80

def bytes(format)
  java_bytes = guard { bytes_impl(format) }
  String.from_java_bytes java_bytes
end

#cropped_thumbnail(size) ⇒ Object

Creates a square thumbnail of the image cropping the longest edge to match the shortest edge, resizes to size, and yields/returns the new image.



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# File 'lib/image_voodoo.rb', line 90

def cropped_thumbnail(size)
  l, t, r, b, half = 0, 0, width, height, (width - height).abs / 2
  l, r = half, half + height if width > height
  t, b = half, half + width if height > width

  target = with_crop(l, t, r, b).thumbnail(size)
  block_given? ? yield(target) : target
end

#flip_horizontally ⇒ Object

Flips the image horizontally and yields/returns the new image.



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# File 'lib/image_voodoo.rb', line 103

def flip_horizontally
  target = guard { flip_horizontally_impl }
  block_given? ? yield(target) : target
end

#flip_vertically ⇒ Object

Flips the image vertically and yields/returns the new image.



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# File 'lib/image_voodoo.rb', line 112

def flip_vertically
  target = guard { flip_vertically_impl }
  block_given? ? yield(target) : target
end

#format ⇒ Object

Returns detected image format from binary representation of input data as upper case string. Eg. JPEG, BMP, PNG. For GWT image representation compatibility method name is :format. It also accepts block and returns format as first block argument. When format not detected or not set it returns nil



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# File 'lib/image_voodoo.rb', line 281

def format
  @format && block_given? ? yield(@format) : @format
end

#greyscale ⇒ Object Also known as: grayscale

Creates a grayscale version of image and yields/returns the new image.



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# File 'lib/image_voodoo.rb', line 121

def greyscale
  target = guard { greyscale_impl }
  block_given? ? yield(target) : target
end

#guard(&block) ⇒ Object 



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# File 'lib/image_voodoo.rb', line 243

def guard(&block)
  ImageVoodoo.guard(&block)
end

#height ⇒ Object

Returns the height of the image, in pixels.



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# File 'lib/image_voodoo.rb', line 251

def height
  @src.height
end

#i_am_feeling_lucky ⇒ Object

GAE Automatically adjust contrast and color levels.



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# File 'lib/image_voodoo/gae.rb', line 15

def i_am_feeling_lucky
  transform(ImagesServiceFactory.make_im_feeling_lucky)
end

#negative ⇒ Object

Creates a negative and yields/returns the new image.



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# File 'lib/image_voodoo.rb', line 131

def negative
  target = guard { negative_impl }
  block_given? ? yield(target) : target
end

#paint(src = dup_src) {|src.graphics| ... } ⇒ Object

AWT paint/render to the source

Yields:

  • (src.graphics) 


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# File 'lib/image_voodoo/awt.rb', line 105

def paint(src=dup_src)
  yield src.graphics
  src.graphics.dispose
  ImageVoodoo.new(src, @format)
end

#preview(&block) ⇒ Object

AWT Creates a viewable frame displaying current image within it.



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# File 'lib/image_voodoo/awt.rb', line 94

def preview(&block)
  frame = JFrame.new("Preview")
  frame.add_window_listener WindowClosed.new(block)
  frame.set_bounds 0, 0, width + 20, height + 40
  frame.add JImagePanel.new(self, 10, 10)
  frame.visible = true
end

#resize(width, height) ⇒ Object

Resizes the image to width and height and yields/returns the new image.



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# File 'lib/image_voodoo.rb', line 155

def resize(width, height)
  target = guard { resize_impl(width, height) }
  block_given? ? yield(target) : target
rescue NativeException => ne
  raise ArgumentError, ne.message
end

#save(file) ⇒ Object

Saves the image out to path. Changing the file extension will convert the file type to the appropriate format.



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# File 'lib/image_voodoo.rb', line 167

def save(file)
  format = File.extname(file)
  return false if format == ""
  format = format[1..-1].downcase
  guard { save_impl(format, JFile.new(file)) }
  true
end

#scale(ratio) ⇒ Object

Resize (scale) the current image by the provided ratio and yield/return the new image.



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# File 'lib/image_voodoo.rb', line 180

def scale(ratio)
  new_width, new_height = (width * ratio).to_i, (height * ratio).to_i
  target = resize(new_width, new_height)
  block_given? ? yield(target) : target
end

#thumbnail(size) ⇒ Object

Creates a proportional thumbnail of the image scaled so its longest edge is resized to size and yields/returns the new image.



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# File 'lib/image_voodoo.rb', line 191

def thumbnail(size)
  target = scale(size.to_f / (width > height ? width : height))
  block_given? ? yield(target) : target
end

#to_java ⇒ Object

Returns the underlying Java class associated with this object. Note: Depending on whether you are using AWT or GAE/J you will get a totally different Java class. So caveat emptor!



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# File 'lib/image_voodoo.rb', line 269

def to_java
  @src
end

#width ⇒ Object

Returns the width of the image, in pixels.



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# File 'lib/image_voodoo.rb', line 259

def width
  @src.width
end

#with_crop(left, top, right, bottom) ⇒ Object

Crops an image to left, top, right, and bottom and then yields/returns the new image.



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# File 'lib/image_voodoo.rb', line 201

def with_crop(left, top, right, bottom)
  image = guard { with_crop_impl(left, top, right, bottom) }
  block_given? ? yield(image) : image
end