[sillycross]

It seems like the last "Improving the color" step is what gives most of the atheistic effects (by comparing the second last picture and the final result on the top).

Unfortunately the explanation for that step is only a few sentences..

[mparr4]

That step could certainly be its own post of greater length than this one.

For this particular map it involves separate curve adjustment layers for the water and land. We generally increase the steepness of the curve (increasing contrast) and then adjust individual color channels to get the color balance right. We also do some localized burning (darkening) in areas where pushing the curve resulted in some pixels getting too bright.

I’d love to put together a post with lots of pictures and details about how we do this. It is motivating knowing there is an audience for it.

[sillycross]

Thanks for the explanation! When I read the article, I felt the last step is much more complex than it is said. It seems like you confirmed this point.

I will be very excited to see a post on how these aesthetic improvements are made!

[pope_meat]

Bump the contrast and saturation and you'll be pretty close I reckon.

[sillycross]

As someone who don't know how to use Photoshop, it's interesting to learn (as you said) that, most the difference is only contrast and saturation.

The final image just looked so much better than the second last one for me.

[jasonwatkinspdx]

Photoshop gives you a lot of tools to tweak beyond simple contrast and saturation sliders. The curves UI has been in it in some form since very early versions in the 90s. It lets you dial in a transfer function for each color channel (or luminance) as a bezier curve. The UI shows you a histogram so you can easily understand what's going on with the actual numerical values, avoid clipping, etc. There's plenty of smart tools in the more recent versions too.

Another simple but subtle advantage is you can do these corrections in a perceptual or near perceptual color space like CIELAB, rather than simple RGB. Particularly when you're pushing saturation this gives more natural looking outcomes.