You can do that with ffmpeg and imagemagic. Install them if they are not installed on your PC.
Do these steps in your terminal:
1. Create a directory for trying this solution, you better make a duplicate copy of the videos before trying this.
2. Copy all of your images to that directory
temp you have created.
cp *.JPG temp/.
3. Set the resolution of your images.
mogrify -resize 800x800 temp/*.JPG
4. Convert them to be get morphed for soft transitions and and make them a mp4 video.
convert temp/*.JPG -delay 10 -morph 10 temp/%05d.jpg
ffmpeg -r 25 -qscale 2 -i temp/%05d.jpg output.mp4
ffmpeg is not in the repositories for Ubuntu 14.04, but is in 15.04!