interlace is available for Mac OS X and Linux. Use FieldAssembler for Windows. See About the FieldAssembler for details.
The interlace utility is used to interlace field rendered images. Field rendered images are images in a sequence of images designed for video playback on NTSC devices. Each field, or image, contains only 1/2 of a full frame, and each field is stored in a separate file. Rendering images in this manner can be helpful when designing animations that will be played back on NTSC devices. However, to view these images on a computer screen, or to transfer them to certain other computer programs, you need to reassemble them into full images. When this happens, you end up with half as many files, and each file has twice as much data.
interlace [-a # # #] [-d] [-e #] [-r] [-t str] base_image_name