9 replies to this topic

[The Doomed Mapper]

Hello out there everyone! I have a bit of a question that I have been puzzling over and was wondering if anyone would be interested in providing some input. This is a follow up of sorts to my relief shading post from last month. I am working on a project whose final product would be a shaded relief map of New England, with state borders, highways, and prominent physical features.

I've figured out how to create the relief shading in Natural Scene Designer Pro, and are now looking to find a way to add the roads and state borders to my map through another source of data. The problem stems from the fact that these data sources might be in different projections, making it difficult to ensure that the data overlaps each other correctly when brought into Adobe Illustrator (baring, of course, the fact that some of the data may need to be scaled so they are the same relative sizes). I've seen work where a Cartographer has taken old MAPART .AI files (whose basic projections are known) and used those to provide linework for newly generated shaded relief, if that would be helpful.

Has anyone done this before or have a solution to this overlay problem? Or, less specifically, does anyone have any advice they could give to demystify the process of reprojecting information, particularly for data whose metadata is not well know (for example, a wall map or the like).
I find the process of manual reprojecting (read. scaling in Illustrator) to be frustrating and extremely inexact myself.

[Hans van der Maarel]

Hello Doomed Mapper!

Sounds pretty omnious actually... Maybe I should try my evil laugh too?

It would be a very big plus if you can reproject the vector data into the same projection as your shaded relief. This ensures they match up. Manually reprojecting in Illustrator when you don't have the relevant metadata is indeed very frustrating and error-prone (getting to downright impossible if you have a nasty projection)

I personally use MAPublisher to produce maps in Illustrator, and through that you can reproject vector data. But even then, you have to know which projection it's originally in, otherwise results are not going to look pretty.

[ProMapper]

Hello Doomed Mapper!

Sounds pretty omnious actually... Maybe I should try my evil laugh too?

It would be a very big plus if you can reproject the vector data into the same projection as your shaded relief. This ensures they match up. Manually reprojecting in Illustrator when you don't have the relevant metadata is indeed very frustrating and error-prone (getting to downright impossible if you have a nasty projection)

I personally use MAPublisher to produce maps in Illustrator, and through that you can reproject vector data. But even then, you have to know which projection it's originally in, otherwise results are not going to look pretty.

Yes, I agree with Hans. And if I may add my tuppance here.....you should reproject the data to one common projection system and then do the editing of the road, and other layers to match up exactly with the shaded relief. Once you have achieved a satisfactory degree of accuracy then import this data to Illustrator.

Anu
http://www.mapsandlocations.com

[Charles Syrett]

In reading your post carefully, it looks to me like you're not using a GIS -- at least not yet. It looks like you're asking how to re-project within Illustrator. If that's the case, you'll have to use MAPublisher. To try doing it without the proper software can be very tricky. If you're using the scan-and-trace method, you'll have to do a "local tracing" of detail; i.e., work within a small area at a time, and keep shifting your source material. I've done that before, and it takes a long time! For compilation, usually a combination of a GIS (such as Manifold) and MAPublisher is the best.

Charles Syrett
Map Graphics
http://www.mapgraphics.com

Hello out there everyone! I have a bit of a question that I have been puzzling over and was wondering if anyone would be interested in providing some input. This is a follow up of sorts to my relief shading post from last month. I am working on a project whose final product would be a shaded relief map of New England, with state borders, highways, and prominent physical features.

I've figured out how to create the relief shading in Natural Scene Designer Pro, and are now looking to find a way to add the roads and state borders to my map through another source of data. The problem stems from the fact that these data sources might be in different projections, making it difficult to ensure that the data overlaps each other correctly when brought into Adobe Illustrator (baring, of course, the fact that some of the data may need to be scaled so they are the same relative sizes). I've seen work where a Cartographer has taken old MAPART .AI files (whose basic projections are known) and used those to provide linework for newly generated shaded relief, if that would be helpful.

Has anyone done this before or have a solution to this overlay problem? Or, less specifically, does anyone have any advice they could give to demystify the process of reprojecting information, particularly for data whose metadata is not well know (for example, a wall map or the like).
I find the process of manual reprojecting (read. scaling in Illustrator) to be frustrating and extremely inexact myself.

[The Doomed Mapper]

Hello Doomed Mapper!

Sounds pretty omnious actually... Maybe I should try my evil laugh too?

It would be a very big plus if you can reproject the vector data into the same projection as your shaded relief. This ensures they match up. Manually reprojecting in Illustrator when you don't have the relevant metadata is indeed very frustrating and error-prone (getting to downright impossible if you have a nasty projection)

I personally use MAPublisher to produce maps in Illustrator, and through that you can reproject vector data. But even then, you have to know which projection it's originally in, otherwise results are not going to look pretty.

That's exactly what I would like to do. I come from a GIS background and that was one of the facts that was drilled into my head at the very beginning. I'll look into utilizing MAPublisher as a possible workaround for all this crazy Map Projection that my project seems to require. Curse these companies and their poor metadata practices!

Yes, I agree with Hans. And if I may add my tuppance here.....you should reproject the data to one common projection system and then do the editing of the road, and other layers to match up exactly with the shaded relief. Once you have achieved a satisfactory degree of accuracy then import this data to Illustrator.

Hmm, that's a good point (and something that I wouldn't have though of myself, although it's so blatently obvious when you stop to think about it. I'll keep that in mine when working with data of this nature in the future. Luckily, the company I work for right now does not use a great deal of GIS data, so I am somewhat fortunate in this regard.

In reading your post carefully, it looks to me like you're not using a GIS -- at least not yet. It looks like you're asking how to re-project within Illustrator. If that's the case, you'll have to use MAPublisher. To try doing it without the proper software can be very tricky. If you're using the scan-and-trace method, you'll have to do a "local tracing" of detail; i.e., work within a small area at a time, and keep shifting your source material. I've done that before, and it takes a long time! For compilation, usually a combination of a GIS (such as Manifold) and MAPublisher is the best.

Actually, it is true. I am not using a GIS. A great deal of our work comes from using other images as basemaps and the like, so I'm very familiar with the old "local tracing" way of doing things. The fact that it is so inefficient drives me crazy, hence the question on effective ways of reprojecting my information. However, it's been awhile since I've had a chance to tool around with some GIS, but I'll look into both of the programs that you have mentioned.

Quick Questions: does anybody know of a place that goes into greater detail about the process of reprojection? Such as tutorials or the like? It could prove to be most useful, as some of the mathematics involved are somewhat elusive for me.

Oh, for those of you who are curious, I managed to get around the reprojection issues by repurposing the map from my post last month for use in this project and combining it with a road map of the New England states. The final product is pretty nice (although not as exact as I would have liked it to be). However, the information you folks have presented me with have given me somewhere to start!

[Rick Dey]

Another tool for any raster images you might have that need re-projecting is Avenza's Geographic Imager plugin for PhotoShop.

[The Doomed Mapper]

Another tool for any raster images you might have that need re-projecting is Avenza's Geographic Imager plugin for PhotoShop.

Hmm, a plugin for photoshop? I'm quite the Newbie when it comes to manipulating data in that particular product, but I've been looking for new ways to mess around with the program, so I shall definitely check it out. Thanks for the lead!

[Dennis McClendon]

For relatively small areas (500 km x 500 km), you can get away with just putting everything into some kind of Mercator projection.

I start with base maps (usually USGS 1:250,000 series) that have already been reprojected into Mercator (or a kind of squished Plate-Carrée) by sites such as mapper.acme.com or terraserver.msn.com I make sure to note and draw in the lat-long lines. If I have access to any GIS data, I'll also just put it in some version of Mercator and fit it to the same lat-long lines. Even if I have to trace from a projected map, a Mercator projection allows me to sort of trace square-by-square. You want to take out the slack or make positional corrections in the flatland areas rather than mountainous areas, as the object of all this work is to get the rivers and highways to fall into the canyons properly.

The advantage of this is that I can then use a simple program like MacDEM to produce the shaded relief and then just stretch it to the appropriate lat-long lines. You'll find a good example on page 41 of Cartography Design Annual #1.

[jessz]

I used to have the same problem, which is why I don't have any hair left . . .

For what it's worth, here's my current workflow:

I use Global Mapper to open my NED, SRTM, or other terrain data files (I understand NSD can do this too). I then apply the desired projection to this and export the file as a GeoTiff (Photoshop can open this easily). I then colorize the terrain in Photoshop as desired (again, I think NSD can do this well).

For the vector data (roads, towns, etc) I open these files (usually shapefiles) using Manifold GIS. Once I have all of my data layers in place, I apply the same projection that I used for the terrain (make sure it's exactly the same, with the same parameters). I can then export these files from Manifold in Illustrator format.

In Illustrator, I place the terrain file on the bottom layer, then bring in the vector layers above this. You will probably have to scale the vector info, but it should be proportionally correct and -- this is the important point -- the projections should match.

This does mean, though, that you'll have to spend a few bucks. Global Mapper is about $350, and Manifold is $245 for the basic version. MAPublisher is great, but it's $1,250.

Hope that helps . . .

[Nick H]

I've been doing some work on rendering DEMs recently, using Microdem. I load a DEM into Microdem, subset it and render it using colours from a table, then apply terrain shading and contours. After that I save an image of the result as a WGS84 geotiff (or as a jpg or bitmap with a WGS84 world file). Then I reproject the image as required (using gdalwarp, in my case to the UK Ordnance Survey grid system) all ready for loading as a base layer into software.

Microdem has I'm sure the potential to do a much better job than I'm doing with it. This is a 90-metre DEM rendered in Microdem covering a part of Yorkshire. The contours are too strong, but this is my fault .

Regards, N.

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