* Cacher boutons zoom & pan / display settings-colormap
* No save image !
    // TODO: put colormap code this into ImmVision
    // Pourquoi besoin de ## ? ImmVision::ImageDisplay(std::string("thumb##") + self.name, self.thumbnail());

* Big zoom button
* finish work on animation_image_reduce_factor:
* use ImmVision::ImageDisplay
        (which implies separate Gui for ColorMap)
