Tricking AI Image Recognition - Computerphile

Computerphile
27 Jul 202212:32

TLDRThis video explores object detection using neural networks, comparing human and AI recognition. It demonstrates how small, incremental changes to images can trick AI into misclassifying objects, highlighting the differences in how humans and AI perceive visual data.

Takeaways

  • 🧠 The video discusses object detection using neural networks and compares how humans and AI perceive objects differently.
  • 🕵️‍♂️ It explores the idea of tricking neural networks to misclassify objects by making small, incremental changes to images.
  • 📷 The demonstration uses a picture of sunglasses and an emailed version to show how object detection is performed in MATLAB with a pre-trained network.
  • 🔍 The script mentions the importance of the ImageNet repository, a large database of annotated images used for training and testing AI in image classification.
  • 🏆 It highlights that the current record for image classification accuracy on ImageNet is about 91% across a thousand categories, which is considered very high.
  • 🤖 The video uses a smaller neural network, ResNet, which has a high number of parameters and is known for its accuracy in classification despite being less precise than some other networks.
  • 📊 The script explains how neural networks provide a vector of numbers for each category, with the highest value indicating the most likely object in the image.
  • 🔧 The process of incrementally changing an image pixel by pixel to maximize the likelihood of a specific category is demonstrated, showing how AI can be 'tricked'.
  • 🎨 The video shows examples of how an image of a remote control can be manipulated to be misclassified as different objects like a coffee mug or a golf ball.
  • 🤖 It raises questions about the differences in how AI and humans interpret images, and the potential implications for applications like autonomous vehicles.
  • 🧬 The use of a genetic algorithm to optimize the changes in an image to increase the likelihood of a specific classification is also discussed, emphasizing the complexity of AI decision-making.

Q & A

  • What is the main topic of the video 'Tricking AI Image Recognition - Computerphile'?

    -The main topic of the video is exploring how neural networks perform object detection and whether humans detect objects in the same way as neural networks. It also investigates the possibility of tricking neural networks into misclassifying objects.

  • What is the role of the 'ResNet' in the video?

    -ResNet is a pre-trained neural network used in the video for object detection. It classifies images into categories and provides a likelihood score for each category, indicating the presence of a specific object in the image.

  • What is the size of the image that ResNet accepts for object detection?

    -ResNet accepts images that are resized to 224x224 pixels, as this is the input size it requires for processing.

  • What is the significance of the 'imagenet' repository mentioned in the video?

    -Imagenet is a large-scale image repository that contains millions of images annotated with labels of objects. It is used to train and evaluate the performance of neural networks in image classification tasks.

  • What is the current record for image classification accuracy on Imagenet?

    -At the time of the video, the record for image classification accuracy on Imagenet is about 91%, which is considered very high given the complexity and the number of categories involved.

  • How does the video demonstrate the process of tricking a neural network into misclassifying an object?

    -The video demonstrates this by incrementally changing one pixel at a time in an image, observing how the neural network's classification changes, and keeping changes that increase the likelihood of a desired misclassification.

  • What is the concept of a 'genetic algorithm' used for in the video?

    -The genetic algorithm is used to optimize the process of tricking the neural network. It iteratively makes changes to the image with the goal of maximizing the likelihood of a specific misclassification category, using a limited number of pixel changes.

  • How many categories does the neural network classify images into, as mentioned in the video?

    -The neural network classifies images into a thousand categories, as indicated by the video.

  • What is the conclusion of the video regarding the differences between how humans and neural networks perceive images?

    -The conclusion is that neural networks seem to perceive and classify images in a very different way than humans do, and this difference in perception does not align with human intuition.

  • What is the purpose of the experiment with a blank image in the video?

    -The purpose of the experiment with a blank image is to see how the neural network would classify an image without any pre-existing features, by making incremental changes from a completely blank state.

  • What is the final observation made in the video about the neural network's ability to categorize objects?

    -The final observation is that neural networks are exceptionally good at categorizing objects, but they do so in ways that are not easily interpretable by humans, and sometimes the changes made to trick the network result in abstract or nonsensical images.

Outlines

00:00

🕵️‍♂️ Object Detection with Neural Networks

This paragraph introduces the concept of object detection using neural networks, specifically comparing human perception with that of AI. The speaker plans to trick neural networks to see if humans can be deceived in the same manner. The demonstration involves using MATLAB to load a pre-trained network, ResNet, and resizing an image of sunglasses to fit the network's input requirements. The goal is to classify the image and understand how the network uses a repository of annotated images from ImageNet to make predictions. The speaker discusses the complexity of the task, with over a thousand categories and a high accuracy rate of around 91%. The explanation also touches on the size and complexity of ResNet, highlighting the millions of parameters within the network.

05:01

🔍 Manipulating Neural Networks for Misclassification

The speaker describes an experiment to manipulate a neural network into misclassifying an image of a remote control as various objects such as a coffee mug, computer keyboard, envelope, golf ball, and photocopier. The process involves making incremental changes to the image, one pixel at a time, to increase the likelihood of a specific classification according to ResNet. The results show that even with minor alterations, the network can be led to 'believe' the image represents an entirely different object. The speaker also discusses the potential implications of such behavior in applications like driverless cars and the importance of understanding these networks to prevent misclassification in critical situations.

10:03

🧬 Genetic Algorithms for Image Classification

In this paragraph, the speaker explores the use of genetic algorithms to further manipulate image classification by neural networks. The goal is to change the categorization of a remote control image by altering only a limited number of pixels, specifically 100 out of the approximately 50,000 in a 224x224 image. The fitness function of the genetic algorithm is designed to maximize the likelihood of a specific category, such as a golf ball, over the original classification of a remote control. The speaker presents the outcomes for different categories and notes the difficulty in achieving a high level of classification certainty with minimal pixel changes, reflecting on the exceptional ability of neural networks to categorize images despite the seemingly nonsensical alterations.

Mindmap

Keywords

💡Object Detection

Object detection is a computer vision technique that identifies and locates objects in images or videos. In the video, object detection is performed using neural networks, specifically a pre-trained network called ResNet, to classify images and determine what objects they contain. The script demonstrates how sunglasses are detected and classified by the network.

💡Neural Networks

Neural networks are a set of algorithms designed to recognize patterns. They are inspired by the human brain and are used in various applications, including image recognition. The video discusses how neural networks are used to trick AI into misclassifying objects, showcasing the differences in how humans and AI perceive images.

💡ResNet

ResNet, short for Residual Network, is a type of convolutional neural network that is particularly good at image recognition tasks. It is mentioned in the script as the network used for object detection, highlighting its ability to classify images into thousands of categories despite its complexity.

💡Image Resizing

In the context of the video, image resizing refers to the process of altering an image's dimensions to fit the input requirements of a neural network. The script mentions that images need to be resized to 224x224 pixels to be processed by the ResNet network.

💡ImageNet

ImageNet is a large-scale image database organized according to the WordNet hierarchy. The video script refers to ImageNet as a repository of annotated images used to train and test neural networks, emphasizing its role in benchmarking the performance of AI in image classification.

💡Category

In the script, 'category' refers to the label assigned by the neural network to an image based on its content. The network outputs a category variable that indicates the most likely object present in the image, such as sunglasses or a coffee mug.

💡Convolutional Neural Networks (CNNs)

CNNs are a class of deep neural networks widely used for analyzing visual imagery. The script briefly touches on the layers of CNNs and their role in analyzing features within images, which is crucial for the object detection process.

💡Genetic Algorithm

A genetic algorithm is a search heuristic that mimics the process of natural evolution. In the video, a genetic algorithm is used to incrementally adjust an image's pixels to maximize the likelihood of a specific classification by the neural network, demonstrating how AI can be 'tricked' into misclassification.

💡Feature

In the context of neural networks, a feature refers to a specific aspect of the data that the network uses to make decisions. The script discusses how networks like ResNet identify features in images, although it is difficult for humans to interpret these features directly.

💡Misclassification

Misclassification occurs when an AI system incorrectly identifies the category of an object in an image. The video's main theme revolves around tricking neural networks into misclassifying objects, such as turning a remote control into a coffee mug, by making subtle changes to the image.

💡Incremental Changes

Incremental changes refer to the small, step-by-step modifications made to an image in an attempt to alter its classification by a neural network. The script describes a process where one pixel is changed at a time to gradually shift the network's classification from one object to another.

Highlights

The video explores object detection using neural networks and compares human and AI detection methods.

A pre-trained network is used for object detection, and images are resized to 224x224 to fit the ResNet model.

The ImageNet repository is mentioned as a source of annotated images for training AI in object recognition.

ResNet achieves about 70-71% accuracy in classifying images from a thousand categories, which is considered good.

The video demonstrates how neural networks classify images by assigning probabilities to categories.

Incremental changes to an image can be made to trick a neural network into misclassifying the object.

The experiment shows that even a small number of pixel changes can significantly alter the neural network's classification.

The video attempts to trick ResNet into misclassifying a remote control as various objects like a coffee mug, computer keyboard, envelope, golf ball, and photocopier.

Despite the changes, humans can still recognize the original object in the image, highlighting a difference in perception between humans and AI.

Starting with a blank image, the video shows how a neural network can be tricked into classifying it as specific objects through incremental changes.

The experiment with a blank image demonstrates the neural network's ability to 'see' objects that are not visually apparent to humans.

The video discusses the potential implications of AI misclassification in applications like autonomous vehicles.

The video uses a genetic algorithm to optimize the changes made to an image to maximize the likelihood of a specific classification.

Only changing 100 pixels in an image can significantly alter the neural network's classification, showing the sensitivity of AI to small changes.

The video concludes that while neural networks are exceptionally good at categorizing objects, their methods differ from human intuition.

The experiment suggests that the neural network's classification process might be based on abstract features rather than recognizable shapes.