How do you make a video using images?
Should each image become a video frame or should a single image be repeated?
If the former, put images (jpg, png or bmp with identical dimensions), named <imageName><counter>.<extension> (e.g. kittens-playing000.jpg, kittens-playing001.jpg, kittens-playing002.jpg and so on, the counter increment must be equal 1, no jumps or holes) into a folder and open the first one in Avidemux. Remaining images will be loaded automatically resulting in a short video sequence with the default 25 fps frame rate.
If it is the latter, open the image in Avidemux, select a video codec other than copy and add the "Still Image" video filter.