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Keras reimplementation of "One pixel attack for fooling deep neural networks"

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Re: Keras reimplementation of "One pixel attack for fooling deep neural networks"

#41
post #19
post #15

Earlier quoted context omitted.

That's only because the attack is designed to target that particular network. Just wait until we understand real brains better and can generate tailored attacks...

Isn't that basically what an optical illusion is?

Yes, and also this: https://en.wikipedia.org/wiki/Dazzle_camouflage

Hacks human brain rather efficiently.

Re: Keras reimplementation of "One pixel attack for fooling deep neural networks"

#43
post #15

Earlier quoted context omitted.

The fact that a human isn't fooled by the attack (we can still recognize the 32x32 images for what they are), points to an interesting gap in the abilities of conventional convolutional neural nets.

That's only because the attack is designed to target that particular network. Just wait until we understand real brains better and can generate tailored attacks...

500,000 years ago our eyes and vision were probably significantly worse than they are today. As our eyes evolved to capture the world better our brains also evolved to correct the errors from our eyes. On the other hand, we feed into our neural networks high quality images. It's true that they are low resolution but they don't contain noticeable noise or artifacts. The attack described here is a smart application of salt and pepper noise. It's ineffective on humans because our vision evolved to filter it out, but a network which has seen only noiseless images is helpless.

I'm curious whether training the network by adding noise and other mutations to the set would make the network more resilient to this attacks. In other words, it's the training set or the network architecture that's vulnerable here?

Re: Keras reimplementation of "One pixel attack for fooling deep neural networks"

#44

Earlier quoted context omitted.

Walk around in the city with a giant yellow square costume and observe the mayhem...

Dressing up as traffic signs might become a thing...

I'm pretty sure that's already illegal on many countries.

Re: Keras reimplementation of "One pixel attack for fooling deep neural networks"

#45
post #33

I’ve mentioned this before but a median filter would nuke the single outlying pixel without too much of an effect on the input image. Is there an attack that can get past such a basic preprocessing step?

This is interesting. I guess then you’d want to focus not on a single pixel but a collection that will still retain some value once filtered.

It would be an interesting experiment.

Re: Keras reimplementation of "One pixel attack for fooling deep neural networks"

#46
post #28

Earlier quoted context omitted.

Jumping on top comment (which I completely agree with) to ask: Why wouldn't a K-fold cross validation enable catching this? I'm curious if the attack adds doubt, in that the prediction algorithm is _close_ to truth but gets confused (likelihood of horse slightly less than dog), versus incorrect certitude (the horse is definitely a dog). One could then attach a weighting, perhaps based on max RGB/CYMK vector norm betw…

I don't believe that many people are using K-fold cross validation at all with deep learning, as the computational overhead is massive.

not as massive as producing a bum model. And most of the overhead in ML is data acquisition, cleaning, normalization and tagging costs.

Re: Keras reimplementation of "One pixel attack for fooling deep neural networks"

#47
post #40

Earlier quoted context omitted.

I don't believe that many people are using K-fold cross validation at all with deep learning, as the computational overhead is massive.

I must be misspeaking then. I'm not suggesting it run during training, but run the classification algorithm X number of times over an input image with chunks areas removed/suppressed from the data.

There is a way to do this in Tensorflow, where you try to expand your training data images by altering them, moving them around, etc. However, this is not used with large training sets.

Re: Keras reimplementation of "One pixel attack for fooling deep neural networks"

#48
post #40

Earlier quoted context omitted.

I don't believe that many people are using K-fold cross validation at all with deep learning, as the computational overhead is massive.

I must be misspeaking then. I'm not suggesting it run during training, but run the classification algorithm X number of times over an input image with chunks areas removed/suppressed from the data.

This is very common. It's an easy way to improve accuracy on a model with a fixed amount of data. They typically crop the image as well as rotate and scale it in order to get a larger data set.

It does make the model more robust, but doesn't seem to help much with finding adversarial examples in the model.

Generating adversarial examples and training on that might be a better approach to solving this.

Re: Keras reimplementation of "One pixel attack for fooling deep neural networks"

#49

This is really interesting, but points out a key importance in training neural nets, which is to design your dataset and training to maximize generalization. For example, in the case of training a neural network for something that is highly safety critical, like an autonomous vehicle, it's important for vehicle and pedestrian detection to be as generalized as possible. In order to achieve high confidence in all sorts…

Walk around in the city with a giant yellow square costume and observe the mayhem...

I recently saw a yellow banana-man in a moshpit at a metal show.

Don’t put breaking expectations past humans. We are adversarial by nature.

Re: Keras reimplementation of "One pixel attack for fooling deep neural networks"

#50
post #33

I’ve mentioned this before but a median filter would nuke the single outlying pixel without too much of an effect on the input image. Is there an attack that can get past such a basic preprocessing step?

Assuming you're talking about adversarial examples in general (a one pixel attack would definitely be stopped by a median filter), yes. Median filters, gaussian filters, gaussian noise, all don't provide significant barriers against attack.
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