scripts/builtin/img_invert.dml

#-------------------------------------------------------------
#
# Licensed to the Apache Software Foundation (ASF) under one
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# to you under the Apache License, Version 2.0 (the
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#
#   http://www.apache.org/licenses/LICENSE-2.0
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#-------------------------------------------------------------

# This is an image data augmentation function. It inverts an image.
#
# .. code-block:: python
#
#   >>> import numpy as np
#   >>> from systemds.context import SystemDSContext
#   >>> from systemds.operator.algorithm import img_invert
#   >>> 
#   >>> with SystemDSContext() as sds:
#   ...     img = sds.from_numpy(
#   ...         np.array([[ 10., 20., 30.],
#   ...                   [ 40., 50., 60.],
#   ...                   [ 70., 80., 90.]], dtype=np.float32)
#   ...     )
#   ...     result_img = img_invert(img, 210.).compute()
#   ...     print(result_img)
#   [[200. 190. 180.]
#    [170. 160. 150.]
#    [140. 130. 120.]]
#
#
# INPUT:
# ---------------------------------------------------------------------------------------------
# img_in     Input image as 2D matrix with top left corner at [1, 1]
# max_value  The maximum value pixels can have
# ---------------------------------------------------------------------------------------------
#
# OUTPUT:
# -------------------------------------------------------------------------------------------
# img_out  Output image
# -------------------------------------------------------------------------------------------

m_img_invert = function(Matrix[Double] img_in, Double max_value) return (Matrix[Double] img_out) {
  img_out = max_value - img_in
}