Recent

Author Topic: Large jpg file  (Read 7604 times)

molly

  • Hero Member
  • *****
  • Posts: 2330
Re: Large jpg file
« Reply #15 on: September 29, 2016, 02:35:23 pm »
I want to store images of the world.
Not even google maps is not storing everything into one single picture file  :D

a) you are not able to show the complete picture to the user all in one go (unless you have some very unorthodox video setup using multiple screens).
b) it is much faster to "divide" your map into smaller squares that are easy to handle and compose the current view from several of those squares.

So, what would you like to do with those "images of the world" ? Simply show them on screen/window in a 2d manner ?

loaded

  • Hero Member
  • *****
  • Posts: 824
Re: Large jpg file
« Reply #16 on: September 29, 2016, 02:40:43 pm »
my goal, to get high-resolution output.
Example:
https://youtu.be/V_qaxOk6eMQ
« Last Edit: September 29, 2016, 03:49:43 pm by loaded »
Check out  loaded on Strava
https://www.strava.com/athletes/109391137

molly

  • Hero Member
  • *****
  • Posts: 2330
Re: Large jpg file
« Reply #17 on: September 29, 2016, 03:10:10 pm »
"Sorry, this video is currently unavailable" is the only thing i am able to retrieve from that link.

loaded

  • Hero Member
  • *****
  • Posts: 824
Re: Large jpg file
« Reply #18 on: September 29, 2016, 03:48:30 pm »
interesting, I checked this link now works. (translating error was :o)
https://youtu.be/V_qaxOk6eMQ
« Last Edit: September 29, 2016, 03:51:59 pm by loaded »
Check out  loaded on Strava
https://www.strava.com/athletes/109391137

J-G

  • Hero Member
  • *****
  • Posts: 953
Re: Large jpg file
« Reply #19 on: September 29, 2016, 07:39:17 pm »
You should be aware that .JPG is not useful for high quality images. It is a 'lossy' algorithm such that every time you re-save the image the quality degrades by taking an average of adjacent pixels combining them to reduce the file size and the original quality can never be re-gained.

.PNG and .TIFF are both OK and are not 'lossy' but they do consume more memory.
FPC 3.0.0 - Lazarus 1.6 &
FPC 3.2.2  - Lazarus 2.2.0 
Win 7 Ult 64

Phil

  • Hero Member
  • *****
  • Posts: 2737
Re: Large jpg file
« Reply #20 on: September 29, 2016, 07:53:57 pm »
interesting, I checked this link now works. (translating error was :o)
https://youtu.be/V_qaxOk6eMQ

Looking at that video makes me think you should use a map tile server. As molly suggests above, this allows you to download the map in little pieces and reassemble them as a single image in the client app. This also allows them to be downloaded asynchronously.

Here's an example of using a map tile server in a Web app:

https://dl.dropboxusercontent.com/u/28343282/MacXPlatform/WebAppOverview_2.html

To download tiles in a desktop app, here's how the tiles are named:

http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames

You should be able to use just about any tile server that has the imagery you want to display.

loaded

  • Hero Member
  • *****
  • Posts: 824
Re: Large jpg file
« Reply #21 on: September 29, 2016, 09:36:29 pm »
Hi J-G, Very Thanks ;
Jpg or in another format that is not important. Large size can be used comfortably important.


Hi Phil, I thank you ;
I am grateful for the link you sent.
It can be used as a source.
But now important for me to create a large image file.
Check out  loaded on Strava
https://www.strava.com/athletes/109391137

 

TinyPortal © 2005-2018