Gary Steele described how to use ffmpeg to make a video from images by the command:
ffmpeg -r 10 -b 1800 -i %03d.jpg test1800.mp4
This command only can output a very low quality video. To make the video better, you can try following command:
ffmpeg -f image2 -i %03d.jpg -r 10 -s w*h test1800.mp4
where w and h are the width and hight of the video image, such as 640*480.