Program to calculate size of map and point to point distance.

[Elros]

Your island is less than about 400 miles across: the errors inherent in the map image will overwhelm any likely measurement errors relating to projection. In short, because the island is smallish, you can mostly ignore the projection. If the world itself is flat, then projection is an irrelevant concept.

Now that your map is declared as something that can be measured with a ruler, you need a tool that will measure those distances. There are many tools out there that will do that (try searching for "measure distance on an image web page" in your favorite search engine. Then define that one pixel in your image is X real-world units as shown by your scale bar.

So the dimension are important?
I make this island tiny, but for my book i thinking somethin like europe dimension, if i make that maps the dimension of measure is a problem?

A less complex technique use a physical ruler to measure the scale bar and your desired path directly onscreen, then do the math to convert scale units to real-world units. This also works if you print out the map. The scale bar is the critical part here.

Yea is more simply this method, but i have to decide the scale bar of the map before, right?

[Elros]

Also if you want to measure area then get your map into a black and white image where the island is all black and the background is all white - using contrast or just painting it in. Then you can use the histogram view on most paint packages to count up the percent of the image which is white and black. From that you can usually calculate the area of a complex shaped island real quick.

So if you have a 1000x1000 image and you have a scale bar showing that 100 pixels across is 10 miles then each pixel is 10 / 100 miles or 0.1 miles each pixel. So if your histogram reads off that your island in black is 27.3% of the total white background image, then you have 27.3% of 1000 x 1000 x 0.1 x 0.1 square miles. Which is 0.273 x 100 x 100 which is 2730 square miles.

Math, my enemy , Thanks it will take a few days before i understand but i think is verry helpfull.
So this method is used to calculate the area of island?
If i need to calculate in straight line? something like the length of a river?

[Elros]

I have to ask at all of you, exist any external program?

I know about Campaign Cartographer and Fractal terrain i found on forum list of program on this forum, that program can help me to measure maybe?

I thinking about to use that two program to make my next map.

[waldronate]

Fractal Terrains has a ruler tool that will measure distances on a world (globe or plane). CC3 will measure planar distances and areas.
I like to recommend that people buy a copy of Fractal Terrains when possible, but I did write the program and I do receive income from its sales, so my recommendation may be a bit suspect.

[Elros]

Fractal Terrains has a ruler tool that will measure distances on a world (globe or plane). CC3 will measure planar distances and areas.
I like to recommend that people buy a copy of Fractal Terrains when possible, but I did write the program and I do receive income from its sales, so my recommendation may be a bit suspect.

:O good, can i import my map in that program?
I mean CC3 and Fractal Terrain.

[waldronate]

Both programs will import images, yes. Fractal Terrains can be a bit more complex due to it's projection requirements, but it's not too hard. I can walk you through how to do it if needed (and then everyone will have a reference).

[Elros]

Both programs will import images, yes. Fractal Terrains can be a bit more complex due to it's projection requirements, but it's not too hard. I can walk you through how to do it if needed (and then everyone will have a reference).

Wanderful
Momentarily i can't afford to buy them but i really do care.

I have to chose the scale of map?

As I understand it i can chose the scale, and measure my map right?
And if i import a map from Fractal Terrain to CC3 the scale of map are marked?
Can i import a map from Fractal Terrain to Photoshop with the scale pregenerated in Fractal Terrain?

Sorry for my many question

[waldronate]

You can probably still download the Fractal Terrains demo from the profantasy website. The exports are limited in size and are disabled after the trial period, but the onscreenstuff still works
The demo is for an older revision, I think, but may well be useful.

[Elros]

You can probably still download the Fractal Terrains demo from the profantasy website. The exports are limited in size and are disabled after the trial period, but the onscreenstuff still works
The demo is for an older revision, I think, but may well be useful.

One demo, i like it, but i have to be Prepared for that i have only 1 month to do all, right?

Sorry if i repost my old question down here, can you tell me something about?

As I understand it i can chose the scale, and measure my map right?
And if i import a map from Fractal Terrain to CC3 the scale of map are marked?
Can i import a map from Fractal Terrain to Photoshop with the scale pregenerated in Fractal Terrain?

[waldronate]

You can keep using the demo after the month trial, you just can't export or save data. You can keep measuring distances and viewing things as long as you like. Nothing ever prevents you from taking a screenshot of the program to collect data.

To import your data, you need to do a little math. Your scale bar says that it's 120km across. Loading the map in Photoshop, selecting the scale, copying it, and making a new map from the copy shows that your scale bar is 197 pixels across (for simplicity of the math, I'll declare it to be 200 pixels wide). That means that each pixel in your map is just about 0.6km across (120km/200pix=0.6km/pix). Your whole map is 2000pix by1500 pix, meaning that the map is 1200km by 900km.

For a spherical Earth-sized world (40000 km around at the equator and from one pole through the other and back again), that means that your map is 1200/40000*360=10.8 degrees across and 900/40000*360=8.1 degrees high. Why do you care about that? Because FT's image import assumes that the map edges are specified in degrees. Because we've declared that the map is "flat enough", we don't have to worry about the consideration that FT wants Equirectangular projection images as its input. Because we're only concerned about measuring distances, we can center the image at the equator to reduce errors. If you want to put that image at a specific point in the world, you'll need to reproject that base image using a program such as ReprojectImage ( http://fracterra.com/ReprojectImage.zip ).

Due to a quirk in FT's image process, you need to flip the top and bottom edges to get things upright.

The image below shows how you'd attach your map to an FT world on the left and a measurement across the central lake using FT's ruler tool.

You have a map that already has a scale on it. As described above, your scale can be used to make the map the correct size for a world. If you export from FT to CC3, the scale should be correct for that map. The FT demo is very resolution-limited, so outputting to CC3 from the demo isn't a whole lot of use. You already have a map in Photoshop with the scale on it (that's how you made the JPEG, right)? When the map is imported into F, the original calculations above were done to ensure that FT's understanding of your map was a close match to the information originally expressed in your scale bar.