How to differentiate between a Zeelander 44, 55 and 72?

One day, your life might depend on being able to tell the difference between a Zeelander 44, a 55 and the 72.

Three different models. Which is which?

At first glace, these boat models are quite similar to each other. You could easily think that a Z44 is a Z55 closer to you.

To figure this out, you can spend 5 hours manually reviewing and annotating a thousands photos, deleting bad training data, and staring at tiny thumbnails photos of these boats until your eyes start bleeding.

Then, put this data into a ResNet34, and see that after all of that effort you are able to tell each model from the others 60% of the time. In other words, it guesses correctly less than every two out of three attempts.

A ResNet34 can tell these models from each other 60% of the time.

That’s crap. A waste of time and money.

Here is how you differentiate between these models like a human.

The Z44 has windows in sets of two, the Z55 has windows in sets of three, the Z72 has an uneven window layout, with four large windows in the center, two at the front, and a vent at the back.

When you need to name the model of the boat while flying over it in a helicopter, observe the front deck: the Z44 has a round cover/window, the Z55 has three dark covers, the Z72 has a rectangular cover.

How to tell a Z44 from a Z55 from a Z72 in a glance.

These two rules alone should allow you to tell a Z44 from a Z55 and from a Z72, at least 80% of the time. I hope you don’t stumble onto the remaining 20%, or bad things will happen to you, for sure.

I hope you learned something useful today.

Originally published at https://blog.pedro.si on March 1, 2020.