I think there is a confusion here - HDR = High Dynamic Range images. There are two steps involved here - first combining multiple images at difference exposure to create one image with extended dynamic range. By this, it means each channel will have 16 or more bits information from all the components images. As the traditional media can not display such images, it will have to go through the step of tone mapping - which is to map the 16 bits or more back into 8 bits. The scripts that you were referring to are to do this step. During this mapping, you define regions where you want to simply discard the lower bits information or to do some transformation to show the detailed lower bits information. Well, these are the technical details of HDR processing, you may not want to know too much about it. But, in general HDR images refer to the 16 bits or more per channel images created from the component images and not the tone mapped results.