Given the inherent simplicity of point processing techniques, how vulnerable are these methods to adversarial attacks – subtle, often imperceptible, perturbations crafted to drastically alter the outcome of the enhancement? What novel approaches, beyond traditional signal processing defenses, could be employed to enhance the robustness of point processing pipelines against such attacks, particularly in applications demanding high reliability (e.g., medical imaging or surveillance)?

Considering the range of point processing techniques you've presented, which modify images based on original pixel intensities, in what real-world scenarios do you find these techniques, on their own, to be insufficient for achieving satisfactory image enhancement, and what more advanced methods would you recommend in those cases?