Sequence File: A sequence file is an image file that contains a sequence of images. Each image in the sequence is called a "frame." Image sequences can be 'played' like a movie or slide show. Image-Pro allows you to work with sequence files in three formats: *.avi, *.tif and *.seq. The controls used to 'play' a sequence file appear on the View ribbon when a sequence file is active in the Image-Pro workspace.