You may select NITF 2.1 as an output format from the Output Format drop-down list, which appears in two places:
Two different types of NITF encoding are available: raw (uncompressed) and JPEG 2000.
Because raw files are uncompressed, when NITF 2.1 (Raw) is selected as the output format encode ratio, target file size and other options become unavailable, and the Format-Specific tab of the Advanced Job Options dialog box is absent. Metadata editing is not supported for raw NITF encoding.
When NITF 2.1 (JPEG 2000) is selected as the output format, the source imagery is encoded to JPEG 2000. Thus, when JPEG 2000 is selected, all of the JPEG 2000 encoding options become available. The options common to MrSID formats reappear on the Properties tab . These and all of the options specific to JPEG 2000 become available on the Format-Specific tab of the Advanced Job Options dialog box. For more information about these options, see Advanced JPEG 2000 Options.
You may specify NITF 2.1 as your default output format by selecting it from a drop-down list on the General tab of the Preferences dialog box. For more information, see Setting Preferences.