Movie Edit Pro allows you to export a frame as a BMP or JPG file.
To do this, you need to be in Time-line mode, and place the play cursor on the frame you want as a picture, then go th the drop down menu "File" an select Export, Export as single frame, then choose whether you want BMP or JPG.
Yes, but if you place the time line on the portion of the clip that shows the image in the preview monitor that you want as a single image then you go to File, Export, Export as single frame and then choose JPG then you will get just a single frame image based on the location of the timeline position at the time of export.