1784: Bad Map Projection: Liquid Resize

2017-01-12T19:09:53Z

Alterego9: expanded on a problem with it

{{comic
| number = 1784
| date = January 11, 2017
| title = Bad Map Projection: Liquid Resize
| image = bad_map_projection_liquid_resize.png
| titletext = This map preserves the shapes of Tissot's indicatrices pretty well, as long as you draw them in before running the resize.
}}

==Explanation==
{{incomplete|Partial -- explains a few underlying concepts but needs a lead section}}

There is no perfect way to draw a map of the world on a flat piece of paper. Each one will introduce a different type of distortion, and the best projection for a given situation is sometimes very disputed. Randall previously explored different projections in [[977: Map Projections]], and expressed his disdain for some types he sees as less efficient but whose users feel superior.

In this comic, he suggests a new map projection which is not only useless for most map applications -- as the size, shape, and position of most countries are quite distorted -- but whose creation includes two steps which are outright counterproductive.

First, this method needs a planar map projection as its starting point, thus compounding the problems right off the bat.

Second, the map uses [https://helpx.adobe.com/photoshop/using/content-aware-scaling.html Photoshop's content aware resizing tool] for seemingly no reason whatsoever. The content aware resizing tool resizes images by identifying what it thinks are important details and preserving these, while shrinking or stretching less detailed areas. For example, [http://knowyourmeme.com/photos/710073-content-aware-scaling when used on a face], the algorithm detects that the eyes and mouth are important details and tries to keep these in place, while stretching the skin around it. When applied to a map, this means that areas with lots of countries - and therefore lots of detail - such as Europe, West Africa, the Eastern Mediterranean and Central America/the Caribbean are relatively unchanged, while big countries like India, China and the US are very warped. The choices that the resizing tool makes are also dependent on the exact visual features of the original map, such as the choice of not having any topography or infrastructure drawn on, or not including an altitude/longitude grid, so what areas are deemed as unimportant is even more arbitrary than it would be on, say, a photographic picture of the Earth.

[http://knowyourmeme.com/memes/content-aware-scaling Bad content aware scaling] is already a meme. This projection does do a good job, however, of making almost every country clearly visible and indicating which countries are neighbours.
South America fits into Africa almost as it did in the era of the super-continent [[wikipedia:Pangaea|Pangaea]].

[[wikipedia:Tissot's indicatrix|Tissot's indicatrices]] are equally sized small circles overlaid on a globe to show the distortion of a particular map projection; if the map distortion distorts the shapes or areas of countries, it will do the same to the circles. The title text suggests that the shapes of Tissot's indicatrices would be pretty well preserved by the Liquid Resize transformation, 'as long as you draw them in before running the resize'. Since drawing in the indicatrices first would be identified as details, the Photoshop filter would try not to change them. However, the rest of the map would still change around them, making them useless. This is a play on the common advice to young children to refrain from "running with scissors" to avoid physical accidents.

==Transcript==
:[Caption at the top of the panel:]
:Bad map projection #107:
:<big>The Liquid Resize</big>
:A political map compressed using Photoshop's content-aware resizing algorithm to cut down on unused blank space

:[Below the caption there is a map of the world divided and colored by political boundaries, with outlines around each continent in black and around each country in dark gray. Antarctica is colored in light gray, bodies of water in white, and countries in pale shades of red, orange, yellow, green, blue, and purple. The map is heavily distorted, with Africa in the center and the other continents curving around it, approximating the bounds of a square with rounded corners. The oceans have been removed but also huge countries like the US, Australia, Brazil, Russia and especially India and Argentina have been heavily distorted while areas in the center with many smaller countries like Africa and Europe is almost unchanged.]

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Maps]]

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1784: Bad Map Projection: Liquid Resize