Postimage appears to automatically re-sample images over 1280px wide - BEWARE - always pre-size and save your images locally at 1280px before uploading.
Here are the four main options on Postimage links (use the 4th one):
1) Link:
https://postimg.cc/image/464rkeayh/
Goes to that image on a Postimage page - with Postimage navigation etc.
2) Direct link:
https://s20.postimg.cc/82i3gdvy5/naval_ ... 8_1280.jpg
Goes to that image on Postimage - image only.
3) Thumbnail for forums:

Goes to that image on a Postimage page - with Postimage navigation etc.
4) Hotlink for forums:

Links to Postimage HOME screen.
To embed the image without the link,simply strip the URL tags ...
- Code: Select all
[url=https://postimages.org/][img]https://s20.postimg.cc/82i3gdvy5/naval_a06_fury_558_1280.jpg[/img][/url]
... to give:
- Code: Select all
[img]https://s20.postimg.cc/82i3gdvy5/naval_a06_fury_558_1280.jpg[/img]
Here's the embedded image as it should appear in the screencomp topic:

However - for images 1350px or larger (topics outside the screencomp) - this is where the resampling kicks in. This original is 1350px * 612px.
- Code: Select all
[img]https://s20.postimg.cc/mzqkhf41p/naval_a06_fury_558_1350.jpg[/img]

Note that it's the wrong size - and is often re-sampled to a lower quality (see the artefacts around the tailwheel).
View your image in Postimage, then right mouse click on the "Download original image" link and use the "Copy Link Location" function to grab the URL of the image ...
- Code: Select all
https://s20.postimg.cc/cbrewied7/naval_fury_558_1350.jpg?dl=1
Strip off the "?dl=1" ... which should give you:

Adam.