Class: ImageScience

Inherits:
Object
  • Object
show all
Defined in:
lib/image_science.rb

Constant Summary collapse

VERSION = 
"1.1.7"

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.dpi_to_dpm(dpi) ⇒ Object

Convert a number from dots-per-inch to dots-per-meter



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# File 'lib/image_science.rb', line 157

def self.dpi_to_dpm(dpi)
  (dpi.to_f * (1.to_f/(2.54).to_f) * (100.to_f/1.to_f)).to_f
end

.dpm_to_dpi(dpm) ⇒ Object

Convert a number from dots-per-meter to dots-per-inch



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# File 'lib/image_science.rb', line 151

def self.dpm_to_dpi(dpm)
  (dpm.to_f * (1.to_f/100.to_f) * ((2.54).to_f/1.to_f)).to_f
end

.image_type(path) ⇒ Object

Returns the type of the image as a string.



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# File 'lib/image_science.rb', line 10

def self.image_type(path)
  fif_to_string(file_type(path))
end

Instance Method Details

#[](x, y) ⇒ Object

call-seq:

img[x, y] -> index
img[x, y] -> [red, green, blue]

alias for get_pixel_color



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# File 'lib/image_science.rb', line 134

def [](x, y)
  get_pixel_color(x, y)
end

#[]=(x, y, *args) ⇒ Object

call-seq:

img[x, y] = index
img[x, y] = [red, green, blue]

alias for set_pixel_color



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# File 'lib/image_science.rb', line 144

def []=(x, y, *args)
  set_pixel_color(x, y, *args)
end

#colorspace ⇒ Object

Returns the colorspace of the image as a string



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# File 'lib/image_science.rb', line 24

def colorspace
  case colortype
    when 0 then depth == 1 ? 'InvertedMonochrome' : 'InvertedGrayscale'
    when 1 then depth == 1 ? 'Monochrome' : 'Grayscale'
    when 2 then 'RGB'
    when 3 then 'Indexed'
    when 4 then 'RGBA'
    when 5 then 'CMYK'
  end
end

#colourspace ⇒ Object

:nodoc:



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# File 'lib/image_science.rb', line 35

def colourspace # :nodoc:
  colorspace
end

#cropped_thumbnail(size) ⇒ Object

call-seq:

cropped_thumbnail(size)
cropped_thumbnail(size) { |image| ... }

Creates a square thumbnail of the image cropping the longest edge to match the shortest edge, resizes to size. If a block is given, yields the new image, else returns true on success.



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# File 'lib/image_science.rb', line 79

def cropped_thumbnail(size) # :yields: image
  w, h = width, height
  l, t, r, b, half = 0, 0, w, h, (w - h).abs / 2

  l, r = half, half + h if w > h
  t, b = half, half + w if h > w

  if block_given?
    with_crop(l, t, r, b) do |img|
      img.thumbnail(size) do |thumb|
        yield thumb
      end
    end
  else
    crop(l, t, r, b) && thumbnail(size)
  end
end

#data(*args) ⇒ Object

alias for buffer()



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# File 'lib/image_science.rb', line 42

def data(*args)
  buffer(*args)
end

#dpi ⇒ Object

Returns the DPI of image, as hash of float values



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# File 'lib/image_science.rb', line 175

def dpi
  {:x=>dpi_x,:y=>dpi_y}
end

#dpi_x ⇒ Object

Returns the DPI of x-axis (width) of the image, in dots-per-inch as float



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# File 'lib/image_science.rb', line 163

def dpi_x
  self.class.dpm_to_dpi(dpm_x)
end

#dpi_y ⇒ Object

Returns the DPI of y-axis (height) of the image, in dots-per-inch as float



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# File 'lib/image_science.rb', line 169

def dpi_y
  self.class.dpm_to_dpi(dpm_y)
end

#fit_within(max_w, max_h) ⇒ Object

resize the image to fit within the max_w and max_h passed in without changing the aspect ratio of the original image. If a block is given, yields the new image, else returns true on success.



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# File 'lib/image_science.rb', line 102

def fit_within(max_w, max_h)
  w, h = width, height

  if w > max_w.to_i or h > max_h.to_i

    w_ratio = max_w.quo(w)
    h_ratio = max_h.quo(h)

    if (w_ratio < h_ratio)
      h = (h * w_ratio)
      w = (w * w_ratio)
    else
      h = (h * h_ratio)
      w = (w * h_ratio)
    end
  end

  if block_given?
    self.resize(w, h) do |image|
      yield image
    end
  else
    self.resize(w, h)
  end
end

#image_type ⇒ Object

Returns the type of the image as a string.



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# File 'lib/image_science.rb', line 17

def image_type
  ImageScience.fif_to_string(@file_type)
end

#thumbnail(size) ⇒ Object

call-seq:

thumbnail(size)
thumbnail(size) { |image| ... }

Creates a proportional thumbnail of the image scaled so its longest edge is resized to size. If a block is given, yields the new image, else returns true on success.



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# File 'lib/image_science.rb', line 55

def thumbnail(size)
  w, h = width, height
  scale = size.to_f / (w > h ? w : h)
  w = (w * scale).to_i
  h = (h * scale).to_i

  if block_given?
    self.resize(w, h) do |image|
      yield image
    end
  else
    self.resize(w, h)
  end
end