How Quickly Should Maps Download?

[abrogard]

I think I have my sasplanet configured with no satellite imagery, just google maps.

And I select an area and set it to download it at z22.

It tells me it will take a few days or something like that.

Now I can understand that if I'm downloading satellite imagery in high definition.

But I'm just trying to download this map. A network of country roads. Nearly all blank space.

What is happening?

Is it downloading google earth satellite imagery at the same time?
Have I got it wrongly configured? Am I doing it wrong?
Or even a bare sparse map will really take as long to download as a detailed imagery tile?

[Tolik]

Did you ask yourself what exactly are you downloading? Maybe it's vector? Maybe "blank space" does not occupy any disk space? Think.

[abrogard]

Thanks for that.

Well think, wasn't it that I asked just what is it I'm downloading?

and think, isn't it that no one has told me yet?

and when you think about it didn't I suggest maybe it's downloading more than I ask: a 'base map' too?

and when you think about it blank space doesn't occupy any disk space, does it? because images are typically kept in some compressed format. so that, to invent one, a 1000 x 1000 grid of blank space can be represented by simply a 'top left' coordinate and a 'bottom right' coordinate and a token for the colour within that area. something like: 1234 (top left) AA (colour token) and 2456 ( bottom right ).

using that same technique on a pic with a different colour value for every pixel would make for an enormously different file, far larger than necessary, in fact - would be more economical to simply list the colour values. but it illustrates (no pun intended) what i mean. if you think about it.

if you think about it then it could be that i'm looking for technical information because my thinking has led me to where I feel the need for that kind of help. you know? when you think about it?

thoughtfully yours

ab

[Tolik]

Ok. Right click on Google map and select Copy to clipboard - URL to primary map tile. And open it in browser.
Here is an example: http://mt2.google.com/vt/lyrs=m@1690000 ... 2&s=Galile
One tile, just green, is a png file, 334 bytes. A tile with more information takes a few kilobytes.
That's what SAS.Planet does. It just requests tiles from the server and saves them on disk.
The problem is that you want to download millions of such tiles, and the site may respond slowly.

[QuickBird]

I think I have my sasplanet configured with no satellite imagery, just google maps.

And I select an area and set it to download it at z22.

It tells me it will take a few days or something like that.

Now I can understand that if I'm downloading satellite imagery in high definition.

But I'm just trying to download this map. A network of country roads. Nearly all blank space.

What is happening?

Is it downloading google earth satellite imagery at the same time?
Have I got it wrongly configured? Am I doing it wrong?
Or even a bare sparse map will really take as long to download as a detailed imagery tile?

Gday, first off there is not actual zoom 22, Geoeye reserves that resolution as non-comercial.
Resolutions avobe 21 are blow ups.
But it all depends, zoom doesn't mean image quality and this depends on clouds, angle and distance to ground, Satellites go down as they age and image quality will improve.

Then you bulk downloading from google avobe zoom 20 it will and will be slow, because there are lots of tiles and because you can't split in more than 2 concurrent requests without getting an error 429 with 6 to 12 hours ban from google sat sevice.

I'd say that you go no further than z21, on one single request, and yes it may take days to complete.
Bing has pretty decent and quality imagery for Australia hinterland going up to z18, and it is more download friendly, you can launch many more requests and close the deal in minutes.


Now its my gess, you probably banned by google.
Whenever you see the "Processed Total" count going but the "Downloaded" stopped then yes that might have been it.

You can untick the "download next tile if no response" at Settings / Options /Internet. But honestly that is for error 500s, better not keep calling and stop download and resume at a later time.





About your question on english roadmaps you can:


Settings > Maps Settings > "Base part of request URL" (for maps)
Settings > Layers Settings > "Base part of request URL" (for overlay)

change all 'ru' to 'en', and all 'ru-ru' to 'en-gb' or 'en-us'



for google traffic

http://mt1.google.com/vt?hl=en&lyrs=h@1 ... &style=15&



or you can open the params.txt file on a text editor and edit the DefURLBase so to make the changes permanent


or you can replace the zmp folders with that of the project I once sent you that are corrected on this sense

[abrogard]

Hello quickbird and thanks for that which you sent me some time ago. It is on a different machine in another place.

This machine here just had a system disk crash and now has a new disk/new win10 install and I'm hurriedly trying to populate it with all my usual software.

So that's what's going on here.

My problem here is I've probably misunderstood how it works.

Basicall I am thinking that I should be able to download road maps, street maps, much quicker and easier than downloading satellite images.

So that's not true?

I think this because a satellite image is a densely packed img file - .jpg or whatever.

whereas a portion of a street map is just a few lines on mainly empty space.

You create two pictures in GIMP say and one has a lot of colours and it's a certain size when saved to disk - as .jpg say.
Then create another picture or edit the same one and this time have mainly blank backwash and a few lines - like maps are - and save it as .jpg.

The second one will be much smaller on disk than the first.

So I'm trying to download, to my mind, only the second. The smaller. The road map. Not the satellite image.

It seems that can't be done, right?

I'll try insert or attach a couple of images I just did to demonstrate what I mean.

See? The second is a quarter the size of the first. I was hoping to do that in Sasplanet. Download 'map only' tiles which should be much smaller than 'satellite image full colour' tiles. Download them and check the file sizes.

Okay. I'm wrong. I was only asking. And that's what I was asking. I just want a walking trail map of around here. Something maybe 10km x 10km.

[QuickBird]

Yes, no and depends Abrogard. Depends on the services' server, the load balancing from where you are and your own latency. There may be downtimes sometimes.


Bing road maps are around 13KB each
Bing satellite tiles are around 20kb
Open topo tiles are almost twice that much
Google traffic tiles are 1KB


There has been little difference between downloading sat and road maps, Bing road maps are fast and satellite images too.
Road maps are useful up to z17, Bing maps (Quickbird 2 sat) up to z18 for Australia. Google varies greatly, sometimes holds up to z21 sometimes but sometimes is total shit. Google sat for NZ is awful, I recommend ArcGis Imagery or Bing.



You are probably confused about the TOTAL amount of data since you multiply the number of tiles by aproximately 4 as you go up one zoom, and the data by a magnitude of almost 4.

That is, LETS SUPPOSE, you select an area z15-z18, if your z15 for the area is 1GB then your z16 you will have to expect it to be 4GB, your z17 16GB, your zoom 18 64GB, for that same area.

The number of tiles aren't x4 since the selection drops tiles depending on its made.
The magnitude isn't actually 4 since tiles bear less data as they go up the zoom, let's say x3.5 sometimes x3.




Say an area of 15km x 15km will comprise 30 tiles at z14, 90 at z15, 306 tiles at z16, 1122 tiles at z17, 4290 tiles at z18, 16770 tiles at z19, 66306 tiles at z20, 263000 tiles at z21.

If we talk about GOOGLE you are called Lucky if you get 66 thousand tiles without an error 429, that is google believes you are gang-raping the server and is blocking your IP form some hours. But there is no saying, you might do the job quietly overnight. Just don't split the selection in more than 2 parts (for google).