Exporting Multiple Stills

Apologies if this is a simple fix. I brought in 7 .dng images and added them to my timeline to practice some color correction and color grading. Now I'm trying to export all the images, but I can't figure out how to do it. I've tried exporting as both .tiff and as JPEG 2000 under the video tab and as a file under the file tab and with all of them, but only the last image on my timeline comes out. Everything I've been able to find online talks about grabbing stills from videos. I haven't been able to find anything on using DV to edit images.
Any help is much appreciated!
Any help is much appreciated!