Geospatial imagery is more than just a pretty picture or a backdrop to a map. Today, it is used to provide specific information about a geographic area of interest and can help you make decisions that are important in your line of work.

ENVI EX is the newest addition to the ENVI line of premier image processing and analysis software products. It provides user-friendly tools to read, explore, prepare, analyze, and share information extracted from all types of imagery. Designed specifically for GIS users and fully integrated with ESRI’s ArcGIS® software, ENVI EX includes unique step-by-step workflows that walk you through previously complex image analysis tasks.

What is Orthorectification? Orthorectifi cation is a process that removes the geometric distortions introduced during image capture and produces an image product that has planimetric geometry, like a map. Orthorectified imagery, also known as orthoimagery, is precisely registered to a ground coordinate system and the image scale is constant throughout the entire image. Orthorectifi ed imagery is also free of artifacts, such as leaning objects and crooked linear features, due to relief displacement. These properties make orthoimagery ‘map accurate’ and the clear choice for applications that require accurate positional information and precise measurement of features.

Orthorectification with ENVI EX

Now, ENVI EX provides an RPC-based orthorectification workflow so you can easily generate accurately orthorectified images for use in mapping applications. Rational Polynomial Coeffi cients (RPC) orthorectification is a common alternative to the more complicated rigorous orthorectification method, which requires the use of specific types of data-rich, high resolution imagery and is used in complex scientific applications.

The automated orthorectification workflow in ENVI EX guides you through each step of the process with intuitive dialog boxes and preset parameters, easily taking you from data ingest to orthorectification and beyond.

The ENVI EX orthorectification workflow simplifies the process for orthorectifying imagery. And, ENVI EX is flexible so you can modify parameters and data at any stage of the process, allowing you to get the specific information you need from your imagery and make more informed decisions.

Select and Input Your Imagery
Select the input image and if available the digital elevation model (DEM), that you would like to orthorectify, from web or local search results, from ArcGIS, or from Windows® Explorer and simply drag and drop them into ENVI EX. ENVI EX supports many different types of input files from today’s popular commercial multispectral sensors, such as QuickBird, Ikonos, and NITF.

Select Output Parameters
Next, specify your output parameters such as pixel size, fi le name, and path based on your needs. At any time, you can also check the ENVI EX preview portal window to view your preliminary orthorectification results without the need to process the entire dataset. This saves you time and gives you the ability to modify results by changing and experimenting with different parameters in earlier parts of the workfl ow.