GPSMapEdit *.mp to*.img Detail Lost

[babj615]

After solving previous issues, I am moving along with my map making adventure and have discovered a new issue I cant seem to resolve.

When I export my *.mp map to *.img format with GPSMapEdit/cgpsmapper the resulting map suffers loss of detail that is unacceptable.

In this linked screen capture, you can see the original mp map detail compared to the exported map after installation into MapSource.

Map Levels are:

Level0= 24 Zoom0=0
Level1= 23 Zoom1=1
Level2= 21 Zoom2=2
Level3= 18 Zoom3=3


All Polylines exist on Level0 and are extended up to Level2

Map Header:

; Generated by GPSMapEdit 2.0.77.1

[IMG ID]
CodePage=1252
LblCoding=9
ID=17791779
Name=SW Trails 130808
Preprocess=N
TreSize=250
TreMargin=0.00000
RgnLimit=1000
Transparent=Y
POIIndex=Y
POINumberFirst=Y
POIZipFirst=Y
Levels=4
Level0=24
Level1=23
Level2=21
Level3=18
Zoom0=0
Zoom1=1
Zoom2=2
Zoom3=3
[END-IMG ID]

I have been experimenting with various TRE/RGN values, turning cgpsmapper preprocessing on/off, and have been unsuccesful in maintaining map detail in the final IMG.

I must be overlooking something very simple....

Any thoughts, please?

[popej]

Have you noticed "overzoom" message under Mapsource scale? This means that map precision is too low for that scale.

You can use "SimplifyLevel" in header, values in  range 2 - 3 can help a bit.

[babj615]

Have you noticed "overzoom" message under Mapsource scale? This means that map precision is too low for that scale.

How do I increase map precision for those lower scales?

Edit:

I see CNNANT and GPSFD 24k AZ Topo show overzoom below 500 ft, Garmin 24K Topo below 200 ft, and Garmin 100k Topo below 800 ft.

Is 200 ft the best detail we can currently achieve?

[babj615]

You can use "SimplifyLevel" in header, values in  range 2 - 3 can help a bit.

I am not familiar with this setting.....

[popej]

If you use most detailed level defined as "level0=24", then you have coordinates saved as 24-bit integers, which gives resolution about 2.4m. This is the best that cGPSmapper can do. And with 24-bits you get good view up to zoom 70m/200ft.

SimplifyLevel, cGPSmapper manual, page 12:

SimplifyLevel=n
Simplify level for Douglas-Peucker simplification algorithm. The higher value, the less simplification is done. It is important to note, that with high value, gridding (limitation coming from the format) might be visible.
Default = 1
Valid range is from 0.1 up to 10

[babj615]

Thank you popej. I added 'SimplifyLevel=0.1" to the header myself, recompiled, and see no change. Do header items have to be in specific order?

[IMG ID]
CodePage=1252
LblCoding=9
ID=17791779
Name=SW Trails 130808
Preprocess=N
TreSize=250
TreMargin=0.00000
RgnLimit=1000
SimplifyLevel=0.1
Transparent=Y
POIIndex=Y
POINumberFirst=Y
POIZipFirst=Y
Levels=4
Level0=24
Level1=23
Level2=21
Level3=18
Zoom0=0
Zoom1=1
Zoom2=2
Zoom3=3
[END-IMG ID]

Edit: I read it backward, using higher number now....

Low value = horribly simplified map!

Even using maximum value of 10, the only change I see is that my map is now only visible below 1 mile zoom level, with identical detail.

[popej]

Simplification is about a number of points in a line. Bigger values means more points remain from original drawing. Nothing changes in levels or visibility.

[babj615]

Simplification is about a number of points in a line. Bigger values means more points remain from original drawing. Nothing changes in levels or visibility.

With SimplifyLevel=0.1 my map looked like a preschool art project.
With SimplifyLevel=10 my map looked the same as before I added any value to my header.

Page 12 of cgpsmapper manual states (as you quoted) valid range is from 0.1 up to 10, and Default = 1.

Is it possible the cgpsmapper manual has a typo, and the maximum level is actually 1.0, with a range from 0.1-1.0?

This would suggest that this value decides the percentage of points retained during simplification, where 0.1 = ten percent, 0.5 = fifty percent, and 1.0 = one hundred percent (or NO simplification), which would explain why I see no change between using no value (default = 1) and using value=10.

[babj615]

I have solved the issue with loosing visibility above 1 mile zoom.

My workflow is this:

1. create/edit map in GPSMapEdit
2. save as *.mp
3. export as *.img
4. install *.img into MapSource with MSTK
5. open MapSource to inspect map
6. uninstall map from MapSource with MSTK

I repeat this process each time I want to change a value or edit a specific map detail so I can see how that change will appear in MapSource/BaseCamp (I use MapSource because it loads faster than BaseCamp, and I am impatient).

I have discovered (at least on my Win8 64-bit PC) that each time I make changes and reload a map into MapSource using the same map ID, the changes are not displayed, and only the original map installed with the specific mapID will be displayed, even after uninstalling any previous versions of the map and deleting all associated files.

If I want to see changes each time, I have to install the map with a new mapID every time.

Have any other users experienced this issue, and if so, how can I force MapSource to clear it's cache?

[Seldom]

I have discovered (at least on my Win8 64-bit PC) that each time I make changes and reload a map into MapSource using the same map ID, the changes are not displayed, and only the original map installed with the specific mapID will be displayed, even after uninstalling any previous versions of the map and deleting all associated files.

You know that MS/BC cache graphics and that Control-G flushes the MS/BC graphics cache?
I know that with Win7 if I rebuild a mapset the first time it loads it shows the old graphics, but after I Control-G things look new.  Have you been doing this, and it's not working?  Of course, if you create a new mapset, it would always show up.

[babj615]

I have discovered (at least on my Win8 64-bit PC) that each time I make changes and reload a map into MapSource using the same map ID, the changes are not displayed, and only the original map installed with the specific mapID will be displayed, even after uninstalling any previous versions of the map and deleting all associated files.

You know that MS/BC cache graphics and that Control-G flushes the MS/BC graphics cache?
I know that with Win7 if I rebuild a mapset the first time it loads it shows the old graphics, but after I Control-G things look new.  Have you been doing this, and it's not working?  Of course, if you create a new mapset, it would always show up.

No, I was not doing this. Now that you mention it, I remember doing this once a long time ago, and had forgotten completely about that function.

I knew there had to be a simple solution, there usually is.

Thanks for the heads up, Seldom!

[popej]

Is it possible the cgpsmapper manual has a typo, and the maximum level is actually 1.0, with a range from 0.1-1.0?

This would suggest that this value decides the percentage of points retained during simplification, where 0.1 = ten percent, 0.5 = fifty percent, and 1.0 = one hundred percent (or NO simplification), which would explain why I see no change between using no value (default = 1) and using value=10.

I'm using value 2 and it gives different results than default. Simplification doesn't count percents. When a sequence of points lies on a nearly straight line, simplification removes intermediate points. Parameter decide how far from straight line points are removed. See description of algorithm:
http://en.wikipedia.org/wiki/Ramer%E2%80%93Douglas%E2%80%93Peucker_algorithm

[Red90]

Somewhere there is a setting that causes the data to generalize when imported.  Make sure that is off.

[babj615]

Is it possible the cgpsmapper manual has a typo, and the maximum level is actually 1.0, with a range from 0.1-1.0?

This would suggest that this value decides the percentage of points retained during simplification, where 0.1 = ten percent, 0.5 = fifty percent, and 1.0 = one hundred percent (or NO simplification), which would explain why I see no change between using no value (default = 1) and using value=10.

I'm using value 2 and it gives different results than default. Simplification doesn't count percents. When a sequence of points lies on a nearly straight line, simplification removes intermediate points. Parameter decide how far from straight line points are removed. See description of algorithm:
http://en.wikipedia.org/wiki/Ramer%E2%80%93Douglas%E2%80%93Peucker_algorithm

I had looked at that page yesterday, and the example they give simply shows every other point being removed. I did not see anything in the Wikipedia article that equates to the cgpsmapper 0.1-10 scale.

[babj615]

Somewhere there is a setting that causes the data to generalize when imported.  Make sure that is off.

Oh yes,

Tools > Options > Edit > Snap to grid is disabled!