1784: Bad Map Projection: Liquid Resize

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Bad Map Projection: Liquid Resize
This map preserves the shapes of Tissot's indicatrices pretty well, as long as you draw them in before running the resize.
Title text: This map preserves the shapes of Tissot's indicatrices pretty well, as long as you draw them in before running the resize.

Explanation

Ambox notice.png This explanation may be incomplete or incorrect: Partial -- explains a few underlying concepts but needs a lead section
If you can address this issue, please edit the page! Thanks.

Maps of the world use different types of projection in order to represent spherical world on a flat piece of paper. These projections are often designed to preserve shapes, directions or sizes of countries. Randall's interest in map projections has been mentioned before in 977: Map Projections.

In this case we see a different projection, that uses Photoshop's content aware resizing tool in order to remove areas of similar colour. While this does remove much of the sea, this is not particularly useful. It also distorts India and Australia so that they are unrecognisable.

South America fits into Africa almost as it did in the era of the super-continent Pangaea.

Tissot's indicatrices are equally sized small circles overlaid on a globe to show the distortion of a particular map projection.


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 fill all the blank areas between the continents with little circles, the Photoshop filter (which tries to fill blank space) would then no longer be able to find much contiguous blank space anywhere anymore, and in effect leave the input image almost unchanged.. which indeed would cause the shapes of the indicatrices, along with everything else, to be pretty well preserved.

Transcript

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[Caption at the top of the panel:]

Bad Map Projection #107:

The LIQUID RESIZE

A political map compressed using Photoshop's content-aware resizing algorithm to cut down on unused blank space

[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.]


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Discussion

I'm not too experienced with PhotoShop, but I think that the tool is a selective delete that he used on water bodies, so removing most of the water while maintaining relative shapes and sizes?

Mostly just from the fact that India looks desiccated.

162.158.166.197 05:06, 11 January 2017 (UTC)Girish

Australia is pretty mutilated, so I think the tool was used on land too 162.158.178.111 05:55, 11 January 2017 (UTC)

Where are Laos and Cambodia missing? 108.162.246.11 06:14, 11 January 2017 (UTC)

It seems that Laos and Burma have been merged into one big county, as well as Cambodia and Thailand. Maybe they are just unnecessary details according to this map projection. 162.158.238.22 16:39, 11 January 2017 (UTC)

The tool removes spaces of uniform color automagically. If you have big countries like India or Australia, they get caught by the algorithm as well. 162.158.69.9 06:16, 11 January 2017 (UTC)

Can anybody figure out the projection before the application of the tool? 108.162.219.232 06:58, 11 January 2017 (UTC)

I think it is a Mercator projection that got mutilated. 141.101.104.239 07:50, 11 January 2017 (UTC)
I agree, it looks like a Mercator that Freddy Kruger got at.

Girish, 162.158.166.197 09:02, 11 January 2017 (UTC)

I think if it was a Mercator, the bottom of Antarctica would be flat. To me, it looks like Winkel Tripel, with the odd angles in Alaska and the Russian Far East. Schroduck (talk) 15:02, 11 January 2017 (UTC)

I feel like there is some part of sarcasm in "unused blank spaces", as if it was Randall saying "You're right, why would anyone care about the oceans? There, I have removed them, problem solved.". Can anyone tie this to a recent event? Or maybe the joke is about improperly handling data, where you use a tool just because it's known to work well and for the sake of processing data, even if using in a given context doesn't make much sense. 141.101.69.213 10:14, 11 January 2017 (UTC)

I'm not sure about recent events, but "removing oceans" features prominently in one of Randall's What If? articles. 108.162.241.130 (talk) (please sign your comments with ~~~~)

This map proves, once again, that it's good to be an archipelago. Philippines, FTW! 172.68.54.58 13:59, 11 January 2017 (UTC)

Hold your patriotic horses there, where did Palawan go? --162.158.138.10 12:24, 12 January 2017 (UTC)

Comics like these make me wonder how Randall preserves the XKCD visual style when working with content that is clearly not hand-drawn. ~AgentMuffin

"This is a play on the common advice to young children to refrain from "running with scissors" to avoid physical accidents." <-- Does anyone else thing this is a bit of a stretch? 108.162.245.130 (talk) (please sign your comments with ~~~~)

Yes, I do :) Luckykaa (talk) 15:46, 12 January 2017 (UTC)
absolutely. Running just refers to the algorithm. It's not meta in any way.162.158.58.45 16:29, 12 January 2017 (UTC)

This map centres on Africa, which has survived the distortion relatively unscathed. Might this be a dig at other projections that exaggerate the relative size of Africa? For example, Gall-Peters is called out in xkcd 977 with a simple "I hate you". --108.162.241.130 15:47, 13 January 2017 (UTC)

Maybe but I think it is because all landmasses are more or less centered around Africa. By putting this center there is not need to show any of the Earths half-sphere with the paccific Ocean, which would anyway disappear completely. I think it would be more difficult for people to relate to a map that shows USA up Against China, than US up against Europe. And that may be an important factor when making such a comic. People need to know what they see and what has happened to appreciate the comic. But I'm sure he appreciated that it keeps Greenland and Australia much smaller then Africa, which is not the case for the mercator projection. --Kynde (talk) 20:46, 17 January 2017 (UTC)

It seems to me that this comic is inspired by xkcd 1685, once again making humorous reference to using a Photoshop tool to accomplish an unrelated task. 108.162.215.130 (talk) (please sign your comments with ~~~~)

Agree. Will add 1685: Patch to the explanation. --Kynde (talk) 20:46, 17 January 2017 (UTC)

Can someone please explain the relevance of "political" in the title? Because I understood the resizing of the map to be related to unused blank political space, so that areas with little or no political "content" were cut away, which seems to run counter to what everyone else thinks. But then again, I know absolutely nothing about actual map resizing.

"Political" is a type of map which focuses on showing locations of countries, usually by painting neighbouring ones in different colors.172.68.11.41 09:33, 24 January 2017 (UTC)

This page reads more like a review than an explanation. ★☆☆☆☆ 108.162.212.227 10:16, 7 August 2017 (UTC)


Could someone add Tissot's Indicatives (correct spelling) onto the map as the title text shows? could someone do a reverse liquid resize to put it back to what it was before? 172.69.63.203 16:40, 11 June 2020 (UTC)Bumpf

"Bad content aware scaling is already a meme." -- Well, this is about bad continent-aware scaling! 162.158.155.90 13:21, 30 December 2020 (UTC)


This reminds me of maps for underground train networks, which greatly distort distances but preserve relationships between stops on different rail lines. 172.70.126.116 16:27, 1 March 2023 (UTC)