Module: Tracksperanto::UVCoordinates

Included in:
Export::SynthEyes, Import::Syntheyes
Defined in:
lib/tracksperanto/uv_coordinates.rb

Overview

Syntheyes and some other apps use a relative UV coordinate sustem. For Syntheyes, zero is at the optical center of the image, and goes positive right and up. Since Tracksperanto works in absolute pixels we need to convert to and fro.

Instance Method Summary collapse

Instance Method Details

#absolute_to_uv(abs_x, abs_y, w, h) ⇒ Object

UV coords used by Syntheyes and it’s lens distortion algos.



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# File 'lib/tracksperanto/uv_coordinates.rb', line 8

def absolute_to_uv(abs_x, abs_y, w, h)
  [convert_to_uv(abs_x, w), convert_to_uv(abs_y, h) * -1]
end

#convert_from_uv(absolute_side, uv_value) ⇒ Object 



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# File 'lib/tracksperanto/uv_coordinates.rb', line 18

def convert_from_uv(absolute_side, uv_value)
  # First, start from zero (-.1 becomes .4)
  value_off_corner = (uv_value.to_f / 2) + 0.5
  absolute_side * value_off_corner
end

#convert_to_uv(absolute_value, absolute_side) ⇒ Object 



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# File 'lib/tracksperanto/uv_coordinates.rb', line 12

def convert_to_uv(absolute_value, absolute_side)
  x = (absolute_value / absolute_side.to_f) - 0.5
  # .2 to -.3, y is reversed and coords are double
  x * 2
end