Use ffmpeg to create a video from a few images
Use

ffmpeg -framerate 1/X -i img%d.png -r 25 -pix_fmt yuv420p out.mp4


e.g. for each image to show for 2.5 seconds,

ffmpeg -framerate 1/2.5 -i img%d.png -r 25 -pix_fmt yuv420p out.mp4