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Author Topic: Garmin 62s and California Topo: how to avoid too dense contour?  (Read 14135 times)

LucaPCP

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Garmin 62s and California Topo: how to avoid too dense contour?
« on: December 09, 2010, 02:01:13 AM »
I have a Garmin 62s, and I have downloaded the California Topo map.
At large magnification, it is great and very detailed. However, when I zoom out, at some quite useful zoom levels the countour lines become so dense that it's hard to make anything out.
I tried to set the amount of detail to Small, but this degrades quite a bit the map quality even at large magnification, where the contour lines are not too dense.
Is there a way to tell a Garmin unit to just draw a subset of contour lines as one zooms out, so as not to clutter the map?

Boyd

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #1 on: December 09, 2010, 06:14:05 AM »
It sounds like you have already set everything you can. Unfortunately, this is a problem with Garmin's map rendering style. To avoid this problem, the map author can use a custom line type that over rides the default contour line; I have done this on my own maps. But it's something that the author needs to do, and not the user.

With topo maps on the newer Nuvi series, contour lines are really a big problem. As a default, the newer model Nuvi's render them huge and fat, wider than the roads. The map really becomes unreadable as you zoom out.

As a map author, I would like to suggest that other authors consider using a custom bitmap type for contour lines. This allows you to specify the lines in an exact number of pixels, like this (and using a small label font also helps a lot):


maps4gps

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #2 on: December 09, 2010, 06:28:02 AM »
As Boyd has mentioned, there is nothing a user can do; the mapset needs to be recreated.

That mapset was a first (and only) project by that mapauthor and done for a very specific purpose where it was felt a lot of 'detail' was needed in the contours.

Essentially it is way over contoured (20ft where the topography and the USGS topo use a 40ft or even 80ft CI).  The zoom levels at which the various levels (only 2, instead of the usuall 3) display are also not the most appropriate.

The combination of my US Planimetric (non-contour) Northwest and Southwest and California contours 40ft overlay mapsets may be more usefull for you.

jbensman

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #3 on: December 09, 2010, 09:09:57 AM »
Boyd, it sounds more like what maps4gps is describing is the problem. 

When I generate the topo lines, the first thing I do is delete zoom levels 3 and 4.  It seems to me the only thing needed is level 0 and 1 and everything else clutters up the map at higher zooms.  I generally set the topo lines to stop displaying at the .5 mile zoom and the most detail to begin at 500 feet.  In areas with more elevation change, I move it up a bit. 

One time someone with a nuvi did not like the way the nuvi labeld each contour line-it cluttered the screen and made it draw the map slow.  So I made him a typ file that told the GPS not to label the contour lines. 

LucaPCP

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #4 on: December 09, 2010, 12:53:05 PM »
Many thanks, maps4gps!  Yes, in Europe I was used to hiking maps with 25-meter contour lines, so 20 feet is complete overkill.  Thanks for pointing out to me these maps; I loaded them into Basecamp and they look very very good.  The thresholds for showing detail seem to be more appropriate.  I am going to make a map for my Garmin tonight!  It's too bad Basecamp cannot deal with transparent maps (why?), so I cannot have a good preview on my Mac.


Boyd

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #5 on: December 09, 2010, 12:55:44 PM »
It's too bad Basecamp cannot deal with transparent maps (why?), so I cannot have a good preview on my Mac.

Because that's a feature that Garmin doesn't use with their own products, and they make Basecamp/Mapsource to support their products instead of free third party maps.  :)

jbensman

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #6 on: December 09, 2010, 06:15:17 PM »
Actually, garmin has a few transparent trail maps.

LucaPCP, if you have any CA trail data, I can add it to My Trails. 

LucaPCP

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #7 on: December 09, 2010, 08:53:03 PM »
JBensman, I would be most glad to provide trail data.  My previous GPS has been dead for a while, and so I don't have much good data now, but I expect to have trails for the Truckee area and maybe more during this year.  I plan to post them regularly to a blog or site, and I will be most happy to provide them to you.  I don't know how to edit track data, btw, and such data usually needs cleaning up; if you have good suggestions for tools (on Mac) they would be appreciated!  So far, the only tools I know of are Basecamp and Google Earth.

Luca

LucaPCP

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #8 on: December 09, 2010, 10:56:56 PM »
I notice that most maps look a lot better in basecamp than on the Garmin 62s.
It is not only a matter of my laptop screen being (much) larger: the rendering is smoother and more detailed, and with a better choice of colors.

So I am curious: you are all mapping experts.  Is the map rendering better in the Oregon 450s or in the Garmin 62s?  Is there any difference in map readability and choice of colors (aside from the bigger screen size of the Oregon 450s)?

Thanks! Luca

Boyd

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #9 on: December 10, 2010, 07:10:37 AM »
I have an Oregon and a 60csx and a variety of Nuvi's. Basecamp renders the map differently from all of Garmin's outdoor units from my experience. Have not used a 62st, but the screenshots I've seen were similar to the Oregon (with less pixels  :) )

The older units like the 60csx really render the map differently, partly because of the old-fashioned 8 bit screen. If you take a screenshot from these old models (using xImage), it's pretty surprising. Doesn't look at all like what you see on the screen of the unit itself. I guess this has to do with the capabilities of those LCD panels.

Personally, I really dislike what Garmin has done to map rendering over the past few years. They are adding things to my map objects that I don't want. For example, Basecamp renders a thin highlight next to the road and stream lines. If you look at the same map in nRoute (older Garmin software), it is correctly rendered (as I specify in my .typ files).

They are trying to give their maps a certain "look" which is modern and "friendly" I think. To me it looks like "my first topo". I suppose they don't want maps to look too technical for fear that will scare away the consumer.

Sorry - that's just a pet peeve of mine. Since you like that style better than what you see on the GPS, Garmin is probably doing the right thing for most consumers.

Actually, the Nuvi 3790 provides the nicest map rendering of any Garmin product. I think the glass capacitive screen (like an iPhone) helps to produce really vivid colors. Also 800x480 pixels vs 160x240 on your 62s. That's 10x the pixel count of the 62s and it makes a big difference. It can also do high quality true 3d views. I wish Garmin would put this screen and rendering engine into an outdoor handheld.  :)

jbensman

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #10 on: December 10, 2010, 09:19:39 AM »
JBensman, I would be most glad to provide trail data.  My previous GPS has been dead for a while, and so I don't have much good data now, but I expect to have trails for the Truckee area and maybe more during this year.  I plan to post them regularly to a blog or site, and I will be most happy to provide them to you.  I don't know how to edit track data, btw, and such data usually needs cleaning up; if you have good suggestions for tools (on Mac) they would be appreciated!  So far, the only tools I know of are Basecamp and Google Earth.

Luca


I use a PC so I don't know much about MACs.  I use MapSource when I clean up the tracks.  However, most of the time I find it easier to use the draw tool and draw on top of my track and add what I draw to the map.  This is usually easier than cleaning up when you stop, removing where you go off the trail and dealing with when you backtrack.

I wish there was a MAC program that would convert the Windows installers we make into MAC so we did not have to also create a MAC installer (a process I find to be a pain)

LucaPCP

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #11 on: December 10, 2010, 09:32:05 AM »
Re: map rendering:

I just find the choice of colors and contrast very poor, in how my Garmin 62st renders maps.
The shaded relief is way too dark, and roads are gray, terrain brown, contours brown/black... and the result is a dark unreadable mess.
If I use e.g. Google terrain maps on my Android, the result is much more readable.  There is a world of difference between map rendering on my Android, and on my Garmin.  In fact, the only way I find the Garmin usable is to switch terrain and shading off (and many thanks to maps4gps; I very much like the base maps + 40ft contours).  I am surprised that no-one else is doing good shaded maps for Garmin.  I wonder if Garmin will fix the maps and adopt lighter colors for the shading...

Re: redrawing the paths:

On a Mac, I can edit / redraw paths on BaseCamp or Google Earth.  BaseCamp last time I tried had a nasty habit of snapping each path point to something (even to a contour line!), but this can be a virtue I guess when redrawing a path, as I can snap to some of the original points.

Re: the Mac installer:

Which installer?  I just uncompress the .tgz files and then use Garmin MapManager to install the map on the Mac... sorry it is a mess...  I really enjoy having the maps, so I am certainly very grateful.

maps4gps

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #12 on: December 10, 2010, 09:39:23 AM »
Quote
I am surprised that no-one else is doing good shaded maps for Garmin.
Becasue how Garmin codes the necessary elevation data has not been reversed engineered.

Boyd

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #13 on: December 10, 2010, 10:06:07 AM »
Like he said. There are no third party tools to make garmin maps with shaded terrain (DEM data). Realize that Garmin considers their map format proprietary and has never disclosed it. The only reason we have third party maps is due to painstaking work by a few people who reverse-engineered Garmin's format through trial and error.

The other map rendering issues can be pretty easily addressed by the use of something called "custom types", as I described above. But I guess I'm the oddity and most map authors are content with Garmin's defaults, since they don't use this feature.

LucaPCP

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Re: Garmin 62s and California Topo: how to avoid too dense contour?
« Reply #14 on: December 10, 2010, 10:37:48 AM »
Re .typ files:
Boyd, I'd like to know more about how to work with .typ files.  Can you suggest good starting points?  I might enjoy adapting map display formats to my taste.

Re shading:  I thought that the people who produce e.g. the 40ft contours have access to elevation data.  In fact, having access to a symbolic representation of the contours might also be enough, as one can interpolate them with some type of spline surface, and then shade the result.  I am not saying that it is easy.  So, for instance, does maps4gps have elevation data, in order to generate the contours?  Does the USGS make elevation data available?
Once one had the elevation data, one could produce geo-referenced jpgs, as for custom maps.  Again I am not saying it would be easy, or space efficient.  I am just wondering.

 

anything