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Joined: Jan 14, 2005 Posts: 19638 Location: Blackpool , Lancs
Posted: Sat Jan 10, 2009 3:54 pm Post subject:
I hope Garmin are going to fix this soon as those last screen captures are unusable, I certainly wouldn't accept that level of quality from a package costing a small fortune when you consider the device and the mapping. I have never seen blurred maps when using Quo or Memory Map on the PDA units at various scales, neither does the SatMap active 10 do this - Mike
Joined: Dec 28, 2005 Posts: 2003 Location: Antrobus, Cheshire
Posted: Tue Jan 13, 2009 4:50 pm Post subject:
Well - you aren't getting the double roads with this mapping (at least on the 1:50k and 1:25k. There are signs of it on the 1.2m and 0.8m scale road maps however.
But that's the only good news
The 500, 300 and 200 ft scales are showing compression artefacts (esp on the lettering) which are very distracting. I am assuming that you aren't doing any image processing before posting.
It's doubly interesting as the 500-200 ft scale maps are the 1:25k where as the .3m, .2m, 800ft are the 1:50k.
Only the 800ft image is close to being useable in my opinion. No point in having the best mapping in the world and not displaying it to it's full potential. Even the road mapping at 1.2m scale is not clear.
I think GARMIN have shot themsleves in the foot here. It's a massively expensive product and if you buy two areas you get all the UK mapping again. If they just offered 1:50k or 1:25k and did it right they would have a better product. The walker/cyclist who is going to be the prime customer of this mapping isn't really going to use the mapping to get him/her to the start of the adventure - or they will be using something else. For heaven's sake you can buy a nicely featured, in-car satnav with mapping for much less than the cost of one mapping card for the Oregon/Colorado - which was not designed with in-car navigation in mind.
Summary.
It's still far from perfect and not a patch on using MemoryMap on my 640*480 Dell Axim. And it's still not the quality of image you are being shown on the GARMIN website. It would be worth the effort asking them if these are real screen images they are showing. Better still - mail a couple of your screen captures to their support team to see if they think they are all right.
GARMIN - get your act together and do it properly (I know - I should tell them myself!) _________________ Phil
Having sent the initial images to Garmin UK their reply was:-
Quote:
The software was made for walking and cycling use and therefore would need to be used at a closer scale of about 2-300 ft.
In the light of the Discoverer being better at other zoom levels, this poor answer!!
Quote:
If they just offered 1:50k or 1:25k and did it right they would have a better product.
I would prefer, as you suggest, if the auto navigation ability was removed as I already have City Navigator, and that Garmin only include the 1:50k and 1:25k maps. This would eliminate the double roads!
The screenshots on Garmin Website indicate they do not have the auto routing function, as there are no double roads.
Thanks _________________ Garmin Oregon 300 + Garmin iQue 3600
My Zoned Speed Camera Icons, available here.
In response to our discussion last week I have some further information for you.
Thank you for your feedback on the GB Discoverer mapping. This mapping is a new format of mapping which works differently to other maps as it has both an image layer and routing layer. Our software engineers are currently working on an update for the Oregon to improve the way that it displays the image layer and also hide the additional routing layer from the display. This will not have any detrimental effect on the functionality of the mapping and should enhance the display of the GB Discoverer mapping. We anticipate that the update will be released by the end of February, however we hope to release a beta version of the software sooner.
Thank you Garmin UK, you are listening to your customers. _________________ Garmin Oregon 300 + Garmin iQue 3600
My Zoned Speed Camera Icons, available here.
Joined: Jan 21, 2009 Posts: 8 Location: Berkshire, UK
Posted: Wed Jan 21, 2009 5:49 pm Post subject: Over-compressed mapping image data?
Looking at the images, there seem to be two problems:
i) low quality factor (high compression) JPEG of the mapping images.
ii) poor choice of scaling algorithms resulting in blocky images on wide zoomed out images (e.g. the St. Brides Bay examples)
The issue of JPEG quality factor comes down to available storage. How much of the UK is covered by 1:25k mapping, and how much space does it take? Can anybody tell us (eyeQue, perhaps?). Full UK 1:25k coverage at 312ppkm requires about 8GB, 1:50k 1GB, 1:250k 100MB.
Note the IJG copyright notice at the top; that tells you where their JPEG algorithms are coming from. I have no idea if these are good or bad.
I also note that the images are presented with what appears to be True or Magnetic North; the grid lines aren't perfectly horizontal and vertical. If the machine is having to re-project, then it might be doing a bad job. If the maps are stored pre-projected (not sure why you'd do that, given that mag north varies...), then it may be that they've done a poor job on the image interpolation during re-projection; poor algorithm/filter choice or poor implementation.
I notice the sample images on Garmin's website are aligned Grid North. Is there a way of selecting which North is used; e.g. can you select Magnetic North for bearing presentation? Or turn it back to Grid North?
Rothers' image of the Pontsticill Reservoir shows what decent OS mapping can look like in a 240x400 image. This also suggests that Garmin have sub-sampled the mapping image data to something like 120x200 (to reduce the image size by 4), and then up-sampled it to 240x400 to display on the screen. They can then claim to have a 240x400 display, even if it's only effectively 120x200...
It's instructive to take Rother's image, downsize it by half using any imaging tool (e.g. Photo Editor), and then view at twice the size. Then compare it with the original, and the Garmin screen shots... Even more interesting if you rotate the image a few degrees. And reduce the quality factor... I'd post a representative image, but, being a newbie, I haven't figured how to upload images yet.
All this suggests that they really have crammed the JPGs to get them to fit in memory.
"I can actually see all four maps at the different zoom levels and I think these are causing overlap problems/conflicts!"
If Garmin have managed to come up with a system that is somehow merging multiple mapping image data sets (as distinct from GIS overlay data sets), then they're very silly... You would normally select only one mapping image data set, depending on the selected zoom level, and use an appropriate zoom factor to re-scale the mapping image data to suit. That is, you pick the mapping image data set that results in a scale factor closest to unity. What GIS overlay data sets (e.g. road network, placenames, POIs) you then present on top should be user- or mode-selectable.
The road network presentation is a GIS data overlay, NOT raw mapping image data.
* Added support for Custom POI database and category selection
* Added ability to force the Oregon into mass storage mode by holding the power button for 30 seconds while plugged into a USB cable
* Added NMEA 9600 baud
* Improved map zooming
* Improved raster map appearance
* Improved map draw speed
* Improved battery gage for NiMH batteries
* Improved stability when changing profiles
* Fixed roads being shown on top of Garmin GB Discoverer maps
* Fixed airport points not displaying on the map
* Fixed some scan points not working properly with Garmin GB Discoverer maps
* Fixed track logging setting being changed when changing profiles while simulating GPS
I will post Discoverer screenshots for your comments later!!!! _________________ Garmin Oregon 300 + Garmin iQue 3600
My Zoned Speed Camera Icons, available here.
Last edited by eyeQue on Thu Jan 22, 2009 12:50 pm; edited 1 time in total
Whilst the double roads are a problem my main concern with your screenshots is the extremely poor quality of the OS mapping. At first I thought it was that Garmin had got the scaling wrong so the pixels were interpolated, not 1:1, however this does not appear to be the case.
Below is the same 1:50k region, zoomed to 1:1 and extracted from Memory Map then cropped to 240x400. As you can see the coverage is exactly the same so no need to start interpolating. This is the same quality I would get on my RA7000.
Here is my new screenshot [right] to compare against your image[left]:-
. _________________ Garmin Oregon 300 + Garmin iQue 3600
My Zoned Speed Camera Icons, available here.
Joined: Dec 28, 2005 Posts: 2003 Location: Antrobus, Cheshire
Posted: Thu Jan 22, 2009 10:49 am Post subject:
Getting to look a bit more like it! I guess there will be a similar update for my Colorado 300 soon then!
Now it's my birthday in a few weeks time - so the postponed Christmas present may be back on the agenda. The only question is will it be the Lake District or Peak District I go for _________________ Phil
Joined: Jan 21, 2009 Posts: 8 Location: Berkshire, UK
Posted: Thu Jan 22, 2009 2:08 pm Post subject:
eyeQue,
More useful images, thanks.
Looks like their software update has addressed a number of zoom scaling algorithm issues I mentioned above; they've put proper resampling filters in to remove the blocky artefacts.
Can you tell me what 1:25k coverage of the UK you have, and how much memory space it takes?
Can you find a way of making the map image align to grid North?
The whole discoverer image on the SD card containg five different map scales comes to 416,144Mb!
The 1:25 & 1:50 covers only the Pembrokeshire & Brecon National Parks.
Quote:
I notice the sample images on Garmin's website are aligned Grid North. Is there a way of selecting which North is used; e.g. can you select Magnetic North for bearing presentation? Or turn it back to Grid North?
I found this comment by you interesting and have tried without success to alter it!!
Can you suggest a method of achieving it as you seem to have more knowledge than I have.
Here are the screenshots of the options and grid lines.
. _________________ Garmin Oregon 300 + Garmin iQue 3600
My Zoned Speed Camera Icons, available here.
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