Chapter 8 – Beating CAPTCHAs with Neural Networks
Better (worse?) CAPTCHAs
http://scikit-image.org/docs/dev/auto_examples/applications/plot_geometric.html
The CAPTCHAs we beat in this example were not as complex as those normally used today. You can create more complex variants using a number of techniques as follows:
- Applying different transformations such as the ones in scikit-image (see the link above)
- Using different colors and colors that don't translate well to graeyscale
- Adding lines or other shapes to the image: http://scikit-image.org/docs/dev/api/skimage.draw.html
Deeper networks
These techniques will probably fool our current implementation, so improvements will need to be made to make the method better. Try some of the deeper networks we used in Chapter 11, Classifying Objects in Images Using Deep Learning.
Larger networks need more data, though, so you will probably need to generate more than the few thousand samples we did in this chapter in order to get good performance...
