The file extension HDR is associated with multiple programs and applications which include ArcView, HDRsoft, and ENVI. HDR files contain data and information related to the program that created them.
If the extension is related to ArcView, it is a graphics and image file type that contains maps, models, analysis data, lines, shapes, objects, layouts, and other elements which are necessary for performing spatial analysis. ArcView is now referred to as ArcGIS and is a program by ESRI that provides a way to convert data into information that can be analyzed in a Geographic Information System (GIS).
The files associated with HDRsoft are a raster image file type that contains elements which allow you to adjust the appearance of a digital image using Photomatrix. HDRsoft Photomatrix is an image editing application that provides a way to adjust high contrast photos for a more natural looking appearance.
HDR files created with ENVI are a Geographic Information System (GIS) file type that contains header data which describes the layout for a BIL file extension or Band Interleaved by Line. BIL files are image format files that contain image data for multiband images.
How to Open HDR Files
Since HDR files are associated with multiple programs and applications, double click on the file to see if it will automatically open in a default program you have installed on your PC. HDR files can consist of different file types, so you may already have a program which will open them.
If the files are created by ArcView or ArcGIS, you can open them using ESRI ArcGIS Desktop for Windows. ArcGIS can be downloaded as a free trial version on the ESRI website and requires Microsoft .NET framework on a Windows PC. If you have Windows installed on a Mac PC, you must add BootCamp, Parallels, or VMWare in order to open HDR files using ArcGIS. You can also use GDAL, which is an open source geospatial application created by the Open Source Geospatial Foundation (OSGF) and is compatible with Windows, Mac and Linux.
HDR files that are associated with HDRsoft can be opened using HDRsoft Photomatrix, which is available in a free trial version on the HDRsoft website and is compatible with Windows and Mac OS X. You can also open this type of HDR file on Windows and Mac OS X using Adobe Photoshop CS6, which is available in a free trial version on the Adobe website.
If HDR files are related to ENVI, you can open them using Global Mapper. It is available as a free trial download on the Blue Marble Geo website and is compatible with the Windows operating system.