scripts/builtin/img_shear.dml

#-------------------------------------------------------------
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#-------------------------------------------------------------

# This function applies a shearing transformation to an image.
# Uses nearest neighbor sampling.
#
# INPUT:
# ---------------------------------------------------------------------------------------------
# img_in      Input image as 2D matrix with top left corner at [1, 1]
# shear_x     Shearing factor for horizontal shearing
# shear_y     Shearing factor for vertical shearing
# fill_value  The background color revealed by the shearing
# ---------------------------------------------------------------------------------------------
#
# OUTPUT:
# ------------------------------------------------------------------------------------------
# img_out  Output image as 2D matrix with top left corner at [1, 1]
# ------------------------------------------------------------------------------------------

m_img_shear = function(Matrix[Double] img_in, Double shear_x, Double shear_y, Double fill_value) return (Matrix[Double] img_out) {
  img_out = img_transform(img_in, ncol(img_in), nrow(img_in), 1, shear_x, 0, shear_y, 1, 0, fill_value)
}