Converting .pdf maps to a different format for editing

Factual Questions
1

I want to take several maps that I have in .pdf form (see https://topobuilder.nationalmap.gov/) and stitch them together in a big powerpoint file. (I recognize there may be other programs, but I’m not familiar with them…please refrain for a bit from saying “you should do ‘xxxx’ instead.”)

I know the website allows for downloading .tiff as well, which I might pursue instead.

BUT…my question is. “What is the best format to convert the .pdf to?” THe criteria is that I want to preserve the resolution, but I also want to crop, resize, maybe recolor…but mostly I want to maintain resolution of the finer details of the maps.

Is .jpeg, jpeg2000, tiff, png, rtf…or something else a ‘better’ conversion to drop into powerpoint and start editing?

After a few answers, I’ll entertain suggestions on why I’m an idiot for doing it this way, and “I should do XYZ instead.” (I have no other software programs other that standard Office)

2

As you make changes and save jpg it tends to degrade. So I would use .png I find it the best for changing maps or joining them. But that is just my experience.

3

You want to use a vector graphics format like SVG to retain the relative dimensions between objects, Any raster format like TIF, BMP, JPEG, PNG, et cetera have inherent limitations in retaining this information with resizing and rescaling, even those like PNG that have scaleability features.

Stranger

4

I like this idea, but I find that powerpoint doesn’t let me import vector graphics format files.

Eventually, I need to learn another software package to do this, but for now, I’m stuck with my old weapons.

5

You can’t really make a useful vector of PDF maps that originated as rasters (like these scanned topos). You’d have to rasterize them first and I don’t know any rasterization program that would work well on something this complex.

OP, PDF and TIFF are both container formats that can hold JPEG or PNG. Most likely they are JPEGs right now. But yeah, to avoid recompressing them every time and causing a “copy of a copy” quality loss, use PNG or some other lossless format (whatever your graphics editing program supports). It’s fine to then export the finished composite as a JPEG one more time. Nobody watching a PowerPoint will notice the difference.

Now, the “right” way to do this would be to use GIS software like the free QGIS with public datasets to get exactly what you want and output it natively from the vector map tiles. Caltopo.com is another easier option.

6

Vector formats like SVG have the benefit that things like contour lines become entities that can be selected and edited rather than just pixels on the screen and are perfect for things like maps and other line/block fill graphics. Not so good for actual images or for images with color/tone gradients. There are online tools which do a pretty good job of conversion. Inkscape is a freeware tool that edits SVG natively.

7

For future reference, Inkscape is a freeware program that will edit vector graphics files, and easily convert from vector to raster. It does have a learning curve but there are a lot of online resources, and while it isn’t quite Adobe Illustrator it will work for most purposes.

Stranger

8

In the mapping world, though, SVGs are very rarely used. While there are vector datasets available, they are usually ESRI shapefiles or geoJSON or GPX traces etc. You need specialized software to work with them.

It’s possible some simple maps, like a few illustrative ones on Wikipedia, might be exported as SVG for distribution. That likely wouldn’t be the case for a topo map, especially if it has hillshade layers or other relief shading.

There are also geo PDF sub formats that can combine both raster and vector layers, but for the OP’s use case of trying to stitch them together, it doesn’t really change anything. He’s essentially working with a bunch of screenshots.

9

PS I think the free online graphics app photopea.com can also load a bunch of PDFs and lay them out and save it as an JPEG.

10

@Sigene,

I’m on a computer now and took a deeper look. It took a while for the USGS topo maps to get sent to my email.

The situation is actually a lot more complicated than it might seem at first glance. You’re not just dealing with simple images, but multi-layered GeoTIFF pyramids. This means that the .TIFF will show you different levels of detail depending how far zoomed in you are, and it isn’t super straightforward to extract and maintain the highest level of detail for the purposes of compositing them into one big layout.

I think a service like Caltopo.com (which doesn’t have USGS maps but does have other topos that are still really decent), which lets you easily select an area for printing/export when you hit print, might be a lot easier to work with? That workflow only takes a few seconds (select the topo baselayer you want, add any other symbology, hit print, choose an area… you’re good to go.)

Doing something similar with these geoTIFFs might take a lot longer, and I don’t think it will be easy with standard software, including Powerpoint. Both the TIFFs and PDFs you get back aren’t just raw map tiles, but “projected” geographies with page borders and such.

You can see this more clearly by loading them into QGIS:

The two TIFF pages are what two adjacent tiles from the USGS topobuilder looks like, positioned in the right places. Because they’re geotagged, the software can automatically align and reproject them, but because you’re dealing with imported TIFFs, they each have their borders still. They are not vectors, but layers of composited rasters at different levels of detail.

By contrast, the background topo behind the pages is a standard data layer, which is a lot easier to work with (and similar to what Caltopo uses). In QGIS, like in Caltopo, you can just select an extent and export that extent, regardless of how it’s tiled in USGS topobuilder. It is a lot harder to composite individual topo map TIFF exports like this than to just stay inside a GIS tool, select an extent, and then export the area that you want.

But there is quite a bit of a learning curve to doing all that :frowning: You “might” be able to get good enough results just importing the TIFFs into Powerpoint or Photopea and manually dragging and cropping them, but it’s a lot of work for an ultimately kinda messy final product.

If there’s a particular area you want, I’d be happy to make you a PDF of that particular area. It might not be the USGS topo maps in particular but something very similar? Or you can do something pretty similar yourself using Caltopo.com — their free plan lets you print up to a letter-sized export, and paid membership lets you export bigger documents, I think.

11

The Gaia GPS web map (https://www.gaiagps.com/map/) is another similar option, and they DO have the USGS topo maps. You can choose an area, the layers you want, add the trails you want to hike (manually or by import), and then export it as a PDF (including slightly bigger ones). It also syncs to the Gaia app if you want it in your pocket too.

12

thanks. I’m going to poke around on these two platforms and maybe get my desired results. I’m honestly not completely satisfied with the ones I got off of topobuilder…they are very dark and hard to read topo lines.

I’ll give it a stab and if I run into trouble, I may ask for your assistance and advice.

13

(EDIT: This was a simulpost, sorry Sigene. Feel free to poke around Caltopo and Gaia and if they can’t make what you want, let me know and I’d be happy to do it for ya.)

Last post today (sorry!), just a couple more examples…

Cropping to map area in QGIS

With some work in QGIS (separately getting the USGS topo quad boundaries and using them as a mask, the red rectangles in this example), you can precisely crop the downloaded TIFFs into their map areas:

That way you can get rid of the USGS map “collar” (the white frame with the legend and text and such), shown in that image as the translucent background.

But the underlying detail of the exported TIFF, even at max resolution, just isn’t that great:

The right half is showing the USGS topo TIFF, zoomed in all the way. You can see the raster pixelation very clearly, and that’s the extent of the detail. For comparison, the left half of the map is showing one of the many free topo datasets, with higher quality and detail. The stream is more defined, there’s more contours available, and there’s less pixelation.

Or using Caltopo:

Or here’s that same area in Caltopo:

Zoomed out a bit, you can see all its features:

Such as overlapping different topo maps and hiking or motor maps. You can also overlay weather, cell coverage, etc. as you like.

You can also add your own trails, snapping to the major hiking trails, to measure distances:

And finally, you can set one or more print areas for export, including laying out several pages side-by-side and zooming in on certain areas for details:

The finished PDF output looks like this: https://caltopo.com/p/FHA3H

All of that is free, btw.

14

We truly live in a time of miracles.

15

Heh, yeah, I guess the evolutions in mapping are a nice little upside to the overall tech dystopia :slight_smile: The stuff above is really just the tip of the iceberg, too.

You can do fun things like:

A lot of it can be done with free software too, with tutorials on YouTube, etc. If only I were an artist…

16

Just a heads up that you will be getting a very nasty email from my boss about my complete lack of productivity for the next few weeks.

17

Heh. On that note, I should get back to work too…

But coding is less fun than mapping!!