class Array

Extensions to the Array class. These mainly deal with encoding integer arrays as well as conversion between signed and unsigned integers.

Public Instance Methods

to_blob(depth) click to toggle source

Packs an array of (unsigned) integers to a binary string (blob).

@param [Integer] depth the bit depth to be used when encoding the unsigned integers @return [String] an encoded binary string

# File lib/dicom/extensions/array.rb, line 12
def to_blob(depth)
  raise ArgumentError, "Expected Integer, got #{depth.class}" unless depth.is_a?(Integer)
  raise ArgumentError, "Unsupported bit depth #{depth}." unless [8,16].include?(depth)
  case depth
  when 8
    return self.pack('C*') # Unsigned char
  when 16
    return self.pack('S<*') # Unsigned short, little endian byte order
  end
end

to_signed(depth) click to toggle source

Shifts the integer values of the array to make a signed data set. The size of the shift is determined by the given bit depth.

@param [Integer] depth the bit depth of the integers @return [Array<Integer>] an array of signed integers

# File lib/dicom/extensions/array.rb, line 29
def to_signed(depth)
  case depth
  when 8
    self.collect {|i| i - 128}
  when 16
    self.collect {|i| i - 32768}
  else
    raise ArgumentError, "Unknown or unsupported bit depth: #{depth}"
  end
end

to_unsigned(depth) click to toggle source

Shifts the integer values of the array to make an unsigned data set. The size of the shift is determined by the given bit depth.

@param [Integer] depth the bit depth of the integers @return [Array<Integer>] an array of unsigned integers

# File lib/dicom/extensions/array.rb, line 46
def to_unsigned(depth)
  case depth
  when 8
    self.collect {|i| i + 128}
  when 16
    self.collect {|i| i + 32768}
  else
    raise ArgumentError, "Unknown or unsupported bit depth: #{depth}"
  end
end