Calculates the Normalized Difference Ratio. \n
* Uses the formula NormDiffRatio = (a-b)/(a+b), \n
* The result image has [-1,1] interval. \n
* Images must be IM_GRAY, and the target image must be IM_FLOAT, except if source is IM_DOUBLE.
*
* \verbatim im.ProcessNormDiffRatio(image1: imImage, image2: imImage, dst_image: imImage) [in Lua 5] \endverbatim
* \verbatim im.ProcessNormDiffRatioNew(image1: imImage, image2: imImage) -> new_image: imImage [in Lua 5] \endverbatim
* \ingroup remotesens
Calculates the Normalized Difference Ratio. \n * Uses the formula NormDiffRatio = (a-b)/(a+b), \n * The result image has [-1,1] interval. \n * Images must be IM_GRAY, and the target image must be IM_FLOAT, except if source is IM_DOUBLE. * * \verbatim im.ProcessNormDiffRatio(image1: imImage, image2: imImage, dst_image: imImage) [in Lua 5] \endverbatim * \verbatim im.ProcessNormDiffRatioNew(image1: imImage, image2: imImage) -> new_image: imImage [in Lua 5] \endverbatim * \ingroup remotesens