Isolate all images from a pdf document

[Gribouillis]

Surely, if it's a pdf made of photocopies with pictures on them, it can't isolate them ?

The pdf contains only 2 images. The first one is a montage of the flowers numbered 1 and 2 and the second image is a single flower.

For example the following image is a single image, it was created with the linux command

Output:
montage -mode concatenate b.jpg b.jpg m.jpg