I just finished the second post in my mini-series about automatic captcha solving. In the first part, I used a multi-label classification approach to show that CNN’s can be used to solve captchas.
In this new part, I’m using single-character classification to turn captcha solving into a standard classification task. The heatmap function in plot_top_losses produced some very nice visuals. In fact it was so useful, I consider moving the heatmap generation into it’s own function. That way we could use it to explain the models decision for arbitrary inputs.
