A lot of people want to be able to extract still images from frames in their video footage especially now that much video is shot in 1080p HD which means the resulting images will be 1920*1080 pixels - more than my first digital camera!
If you own a Canon DSLR camera then you already have the software to do this called Zoombrowser. This will let you move frame by frame and save images as JPG. This can be from any video footage, not just from Canon cameras.