Module: Axon

Defined in:
lib/axon.rb,
lib/axon/fit.rb,
lib/axon/cropper.rb,
lib/axon/scalers.rb,
lib/axon/generators.rb,
lib/axon/alpha_stripper.rb,
ext/axon/interpolation.c,
ext/axon/jpeg.c,
ext/axon/png.c

Defined Under Namespace

Modules: Interpolation, JPEG, PNG Classes: AlphaStripper, BilinearScaler, Cropper, Fit, Image, NearestNeighborScaler, Noise, Solid

Constant Summary collapse

VERSION = 
'0.2.0'

Class Method Summary collapse

Class Method Details

.jpeg(thing, *args) ⇒ Object

:call-seq:

Axon.jpeg(thing [, markers]) -> image

Reads a compressed JPEG image from thing. thing can be an IO object or a string of JPEG data.

markers should be an array of valid JPEG header marker symbols. Valid symbols are :APP0 through :APP15 and :COM.

If performance is important and you don’t care about any markers, you can avaoid reading any header markers by supplying an empty array for markers.

When markers is not given, all known JPEG markers will be read.

io_in = File.open("image.jpg", "r")
image = Axon.jpeg(io_in)         # Read JPEG from a StringIO

jpeg_data = IO.read("image.jpg")
image_2 = Axon.jpeg(jpeg_data)   # Read JPEG from image data

io_in = File.open("image.jpg", "r")
image_3 = Axon.jpeg(io_in, [:APP2]) # Only reads the APP2 marker



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# File 'lib/axon.rb', line 37

def self.jpeg(thing, *args)
  thing = StringIO.new(thing) unless thing.respond_to?(:read)
  reader = JPEG::Reader.new(thing, *args)
  Image.new(reader)
end

.jpeg_file(path, *args) ⇒ Object

:call-seq:

Axon.jpeg_file(path [, markers], &block) -> block_result

Opens the file located at path and reads it as a compressed JPEG image.

markers should be an array of valid JPEG header marker symbols. Valid symbols are :APP0 through :APP15 and :COM.

If performance is important and you don’t care about any markers, you can avaoid reading any header markers by supplying an empty array for markers.

When markers is not given, all known JPEG markers will be read.

This method returns the result of the block.

Axon.jpeg_file("image.jpg", [:APP2]) do |image|
  image.png_file("image.png") # saves "image.jpg" to "image.png"
end



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# File 'lib/axon.rb', line 62

def self.jpeg_file(path, *args)
  File.open(path, 'rb') do |f|
    yield jpeg(f, *args)
  end
end

.png(thing) ⇒ Object

:call-seq:

Axon.png(thing) -> image

Reads a compressed PNG image from thing. thing can be an IO object, the path to a PNG image, or binary PNG data.

io_in = File.open("image.png", "r")
image = Axon.png(io_in)         # Read PNG from a StringIO

png_data = IO.read("image.png")
image_2 = Axon.png(png_data)    # Read PNG from image data



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

def self.png(thing)
  thing = StringIO.new(thing) unless thing.respond_to?(:read)
  reader = PNG::Reader.new(thing)
  Image.new(reader)
end

.png_file(path, *args) ⇒ Object

:call-seq:

Axon.png_file(path, &block) -> block_result

Opens the file located at path and reads it as a compressed PNG image.

This method returns the result of the block.

Axon.png_file("image.png") do |image|
  image.jpeg_file("image.jpg") # saves "image.png" to "image.jpeg"
end



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# File 'lib/axon.rb', line 97

def self.png_file(path, *args)
  File.open(path, 'rb') do |f|
    yield png(f, *args)
  end
end