A meta file is a text file that contains the names of image files and/or bands to treat as one virtual file. When you later select the meta file for input or processing using File > Open, ENVI retrieves the image data from the individual disk files and treats them as if they were part of the same input file for processing.

  • ENVI meta files can contain images with different data types (byte, integer, floating point, and so forth), which allows you to combine processing of diverse data sets. ENVI does not need to perform file conversions or create intermediate processing files.
  • The files that comprise the meta file must have the same spatial dimensions. You can spatially subset the files if needed; see Step 3 below.
  • The map projection of the first file or band in the meta file determines the projection for the other files/bands. The other files/bands are not reprojected to match the projection of the first file/band. You can also create an ENVI header file to accompany the meta file that defines the map projection.
  • You can include any file type in a meta file as long as the files reside on disk and they are formats that ENVI supports.

Follow these steps to continue:

  1. From the Toolbox, select Raster Management > Create ENVI Meta File. The ENVI Meta File Builder dialog appears.
  2. Click the Add Dataset button and select a file using the Data Selection dialog.
  3. Repeat the file selection process using the Add Dataset button. Input files are listed in the Selected Datasets for ENVI Meta File list.
    • To delete a file from the list in the New File Builder dialog, select the filename and click the Remove button.
    • To change the order in which the files and/or bands are imported, click the Move Up or Move Down buttons.
  4. In the Output Filename field, enter a filename and location.
  5. Select the Display Output option to automatically display the image files and/or bands once the meta file has been created.
  6. Click OK to build the new file.
  7. Optional: You can use the Edit ENVI Header tool create an accompanying header file.