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Old 09-23-2012, 09:16 AM   #2
Long Haul Adventurer
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Joined: Mar 2003
Location: North Central Washington (state)
Oddometer: 5,984
Originally Posted by ignatz72 View Post
Anyone have a fool-proof methodology for getting good looking custom maps onto the Montana? I worked for 5 hours yesterday and came up with one decent one, and failed with another...

I know the process as Garmin explains it using Google Earth (which is simple enough), but it's getting the custom map at the best possible resolution that seems to elude me. Understood that the final quality will depend heavily upon the quality of the original map (that's why the one that failed did so, it's unreadable on the device as the original is pretty crummy).

I am using Graphic Converter (poor man's Photoshop), and I'm hoping someone else has import/export settings that strike a good balance between file size and quality resolution. I've tried 110ppi up to 150ppi on the import and all manner of JPEG options on the export (baseline, progressive, 4:4:4, 4:2:2, 4:1:1, etc., ad nauseum) to try to keep the file size under the limit (which I've found to be around 3.2MB).

Below is an example of a map I imported yesterday, in JPEG form it appears to be fine quality but once I import to the device as a KMZ it doesn't look so great. Is this just a limitation of the device, or a limit imposed due to the ridiculously small file size restriction? You can only make a 3MB JPEG look so good, in other words.

I'm starting to think the custom maps "feature" is just a gimmick...

Thanks in advance.
I'm certainly no expert as I've only done a few CustomMaps but a couple of points I see right off. You can only use simple JPG images: no progressive. Also, you are trying to use a single image to cover a large area. This will most certainly yield very poor quality when rendered on the GPS. You can still cover the same area but use multiple images of higher resolution. They will be assembled as you geolocate them in GE and then save them to KMZ. Makes for a much faster map draw on the GPS as well. You still have to manage the file size and the number of segments (images) and each images data size to stay under the maximums. There are some very good third-party write ups on Garmin CustomMaps if you Google correctly - sorry, I don't have them bookmarked. If you haven't been there, a good place to start is Garmin Forums


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DRTBYK screwed with this post 09-23-2012 at 09:23 AM
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