Projects/Marble/HistoricalMaps - Revision history

Tackat: /* Historical Maps for Marble */

2011-12-25T23:53:34Z

‎Historical Maps for Marble

Tackat: /* Step8: Create a preview icon, a legend and a deployment tarball */

2011-12-25T23:52:47Z

‎Step8: Create a preview icon, a legend and a deployment tarball

Tackat: /* Step8: Create a preview icon, a legend and a deployment tarball */

2011-12-25T23:50:43Z

‎Step8: Create a preview icon, a legend and a deployment tarball

Tackat: /* Step 6: Tile creation */

2011-12-25T23:48:43Z

‎Step 6: Tile creation

Tackat: /* Step 6: Tile creation */

2011-12-25T23:48:28Z

‎Step 6: Tile creation

Tackat: /* B. Reprojecting maps provided in Mercator Projection */

2011-12-25T23:42:43Z

‎B. Reprojecting maps provided in Mercator Projection

Show changes

Tackat: /* Step 5: Adjust the latitude */

2011-12-25T23:28:21Z

‎Step 5: Adjust the latitude

Tackat: /* Step 5: Adjust the latitude */

2011-12-25T23:25:00Z

‎Step 5: Adjust the latitude

Tackat: /* Step 6: Retouch the resulting map */

2011-12-25T23:22:23Z

‎Step 6: Retouch the resulting map

Tackat: /* Step4: Normalize the longitude */

2011-12-25T23:11:02Z

‎Step4: Normalize the longitude

@@ Line 7: / Line 7: @@
 [[http://translate.google.de/translate?sl=de&tl=en&js=n&prev=_t&hl=de&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fde.wikipedia.org%2Fwiki%2FBenutzer%3AKronf%2FListe_historischer_Weltkarten | Map List translated via Google Translate]]
-−
-The Following maps look like good candidates (and haven't been converted for use in Marble yet):
-  * [[http://de.wikipedia.org/wiki/Datei:1594_Orbis_Plancius_2,12_MB.jpg | Plancius 1594]]
 You can choose a map from these lists (or a different place). The map you choose should

@@ Line 467: / Line 467: @@
 ====Step8: Create a preview icon, a legend and a deployment tarball====
-Finally you need to follow Step 8-10 from Section A.
+Now you need to follow Step 8-10 from Section A.
 A last note: Mercator based maps will always look a bit blurry around the equator at low zoom. This is due to undersampling. Therefore we rather suggest to use equirectangular maps as source maps if possible.

← Older revision		Revision as of 23:50, 25 December 2011
Line 468:		Line 468:

	Finally you need to follow Step 8-10 from Section A.		Finally you need to follow Step 8-10 from Section A.
		+
		+	A last note: Mercator based maps will always look a bit blurry around the equator at low zoom. This is due to undersampling. Therefore we rather suggest to use equirectangular maps as source maps if possible.

	===C. Reprojecting maps provided in other Projections===		===C. Reprojecting maps provided in other Projections===

@@ Line 433: / Line 433: @@
 <code>./tileimg.sh mitchell.jpg 0 256</code>
 <code>./tileimg.sh mitchell.jpg 1 256</code>
 <code>./tileimg.sh mitchell.jpg 2 256</code>
 <code>./tileimg.sh mitchell.jpg 3 256</code>
 <code>./tileimg.sh mitchell.jpg 4 256</code>

@@ Line 432: / Line 432: @@
 We then use this script to create the different tile levels. The size of our map is 4096x4096. This equals 256 x 2^4 = 256 * 16 = 4096. So the tile level is "4". We create the tile levels from 0 to 4 by calling our script like this:
-./tileimg.sh mitchell.jpg 0 256
+<code>./tileimg.sh mitchell.jpg 0 256</code>
-./tileimg.sh mitchell.jpg 1 256
+<code>./tileimg.sh mitchell.jpg 1 256</code>
-./tileimg.sh mitchell.jpg 2 256
+<code>./tileimg.sh mitchell.jpg 2 256</code>
-./tileimg.sh mitchell.jpg 3 256
+<code>./tileimg.sh mitchell.jpg 3 256</code>
-./tileimg.sh mitchell.jpg 4 256
+<code>./tileimg.sh mitchell.jpg 4 256</code>
 As a result we get directories 0 to 4 including subdirectories with the tiles inside.

@@ Line 411: / Line 411: @@
 Now we create a new layer in our mercator map template. We copy our historical map and paste it into the newly created layer of our mercator map template.
-Now open the Layers Dialog (Gimp: Windows->Dockable Dialogs) and adjust the Opacity of the upper layer so that it has 70% Opacity and becomes translucent. We then move and scale the historical map so that its coast lines exactly match those of the mercator map template:
+Now open the Layers Dialog (Gimp: Windows->Dockable Dialogs) and adjust the Opacity of the upper layer so that it has 70% Opacity and becomes translucent. We then move and scale the historical map so that its coast lines exactly match those of the mercator map template. You can see that we use a guidance line to properly align the equator:
 [[File:mitchell1866_step4.jpg|300px]]
@@ Line 418: / Line 418: @@
 [[File:mitchell_small.jpg|300px]]
 ====Step7: Create a dgml file====

← Older revision		Revision as of 23:25, 25 December 2011
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	Once this is done we can remove the mercator map template. We add another layer with the background color white and put it below the historical map layer. We use the color picker and pick the average background color of the historical map (i.e. the ocean color). We fill the white background layer with this ocean color.		Once this is done we can remove the mercator map template. We add another layer with the background color white and put it below the historical map layer. We use the color picker and pick the average background color of the historical map (i.e. the ocean color). We fill the white background layer with this ocean color.
		+
		+	[[File:mitchell_small.jpg\|300px]]

	====Step7: Create a dgml file====		====Step7: Create a dgml file====

@@ Line 398: / Line 398: @@
 Now we merge the layers we have created so far.
-====Step 6: Retouch the resulting map====
+====Step 5: Adjust the latitude====
-Now comes the hard part which requires photo retouching skills. This will take a few hours. It might be a good idea to turn some good music on. A graphics tablet might be handy - but it's not necessary: We need to retouch the map. While retouching it's of course important that we still retouch the map in a way that doesn't introduce radical changes. The original spirit of the map should still be preserved.
+Now we save this image and load this mercator map template into gimp:
-An important tool for this part of the task is the <b>clone tool</b>. If you are not familiar with it we suggest to look at the docs or at the video tutorial:
+[[File:mercator.png|300px]]
-http://docs.gimp.org/en/gimp-tool-clone.html
+We check the size of our historical world map. The newly created map needs to have a size that is the upper closest match of values like this: 256, 512, 1024, 2048, 4096, 8192, 16384 (i.e. 256 * 2^x).
-http://www.youtube.com/watch?v=AZKQrqFx2UM
+We resize the mercator map template so that it resembles a square of the width that we chose above (in our case 4096x4096).
-We suggest to use the <b>"Circle Fuzzy" Brush for cloning</b>.
+Now we create a new layer in our mercator map template. We copy our historical map and paste it into the newly created layer of our mercator map template.
-It's also a good idea to <b>make use of layers</b>. On Gimp we suggest to use the <b>.xcf file format</b> from now on.
+Now open the Layers Dialog (Gimp: Windows->Dockable Dialogs) and adjust the Opacity of the upper layer so that it has 70% Opacity and becomes translucent. We then move and scale the historical map so that its coast lines exactly match those of the mercator map template:
-During the retouch phase it's advisable to create "backup files" often so that you can easily return to an earlier state. Use a lossless file format that preserves layers for this.
-So here are things that you should look at:
+[[File:mitchell1866_step4.jpg|300px]]
-a.) You've probably noticed that at the top and bottom part of the map the longitude lines become thicker and skewed towards the poles.
+Once this is done we can remove the mercator map template. We add another layer with the background color white and put it below the historical map layer. We use the color picker and pick the average background color of the historical map (i.e. the ocean color). We fill the white background layer with this ocean color.
-−
-[[File:Hondius_step6a.jpg|200px]]
-−
-We need to fix thit in creative ways: Usually this can be done by first using the clone tool to erase the faulty grids
-−
-[[File:Hondius_step6b.jpg|200px]]
-−
-Once we've used the <i>clone tool</i> the result will look like this:
-−
-[[File:Hondius_step6c.jpg|200px]]
-−
-[[File:Hondius_step6d.jpg|300px]]
-−
-Now we need to restore the missing parts of the longitude lines: We can do this by searching for a "clean" light longitude section that we can easily copy over. You should put the copied part of the longitude line into its own layer. once you've pasted enough line parts into the right positions you can merge all the line-layers into a single layer. You should then use the "Darken" mode on the longitude line layer to "blend" the lines properly into the image: The result will look like this:
-−
-[[File:Hondius_step6e.jpg|200px]]
-−
-Repeat the same procedure with the checkered meridians. The result will look like this:
-−
-[[File:Hondius_step6f.jpg|300px]]
-−
-b.) After our copy/paste operations the grid lines of the original map might not line up completely in all places. Use the <i>Clone tool</i> to adjust the lines so that they come together.
-−
-c.) You might also want to repair some text labels, coordinate scales, stains or other severe bugs. But be careful not to overdo it. Don't add or remove islands, cities or other stuff that wasn't there before.
-−
-Once you are done with retouching <b>save the resulting map into a new file (using the .xcf format in gimp to preserve layers and quality). Make sure that the map hasn't been moved and make sure that there are no "empty" pixels on the top, left, right and bottom. Keep this file as "the original".</b>
-−
-Now we take our new "original" and <b>export the map for usage in Marble</b>:
-−
-Finally flatten the image (i.e. merge all the layers) and scale your map up to a width that is the closest upper match of 675 * 2^x. The image in our example has 3250x1625 pixels. So we scale it up to 5400x2700 pixels. Make sure to keep the 2:1 ratio between width and height.
-Save the resulting image into a separate <b>JPG file with a quality that should be between 85-100%</b> (so good quality and very little lossy compression). The file name should have the original map author of the historical map plus the year in which it was created. All in small caps. In our particular example the file name looks like this:
-−
-<i>hondius1595.jpg</i>
 ====Step7: Create a dgml file====

@@ Line 388: / Line 388: @@
 ====Step4: Normalize the longitude====
-Now we need to adjust the longitude of our worldmap so that it somewhat matches that of modern maps:
+Now we need to adjust the longitude of our worldmap so that it somewhat matches that of modern maps. Have a look at this map:
-−
-Download
-−
-[[File:mitchell1866_step3.jpg|300px]]
 [[File:mercator.png|300px]]
-[[File:mitchell1866_step4.jpg|300px]]
+[[File:mitchell1866_step3.jpg|300px]]
-−
-Then resize the map so that the size matches the size of your reprojected world map.
-Once that is done open your reprojected world map and copy it. Then you go back to the scaled bluemarble.jpg and insert it there as a new layer on top of the satellite image (in Gimp: Edit->Paste as New Layer).
-−
-Now open the Layers Dialog (Gimp: Windows->Dockable Dialogs) and adjust the Opacity of the upper layer so that it has 70% Opacity and becomes translucent:
-−
-[[File:hondius_step5a.jpg|200px]]
-−
-Now you need to move the upper layer so that both maps align at 0° longitude. The definition of the prime meridian has changed throughout the centuries. Therefore we take approximately London (Greenwich) as a reference point. You might also want to take the coastline of Middle Europe and middle Africa into account. The result will look about like this:
-−
-[[File:hondius_step5b.jpg|200px]]
-−
-Now set the opacity of the top layer back to 100%. You can see that the right part of the map has moved out of the canvas area. We need to cut this part off: You can increase the width of the canvas a bit to get hold of the overhanging part. Then cut and paste the overhanging part into a new layer on the left. The result should look like this:
-−
-[[File:hondius_step5c.jpg|200px]]
-−
-Delete the layer which still contains the bluemarble.jpg. Flatten the image so that there is just a single layer left.
-<i>Double check that there are no pixel gaps between the pasted areas and no pixel gaps at the image borders.</i>
-Save the resulting image into a new file <b>using a lossless file format</b>.
-Now it's time for a break: A big amount of work is still ahead. After the break we are ready for the next step.
+Now we merge the layers we have created so far.
 ====Step 6: Retouch the resulting map====