here's something which should work right click on an image and select copy image location.
This is how it looks initially now
See the way your browser works if it gets told what size to make an image then it will scale to that size in this case 307 pixels wide and 350 pixels tall. (its just a style applied to the image)
now without the styling information the browser will try to render the picture at its actual size if it will fit in your browser window or scale it to fit. (f11 key will toggle your browser between full screen and its normal display). The page your browser displays can be very simple or very complicated. with just the address of the image your browser displays just the image.
more complicated bit follows you can stop reading here.
The url or address of a page is in the address bar for this page it is http://www.gardenersworld.com/forum/site-feedback/photo-test-thread-only/81736-2.html breaking it down www.gardenersworld.com is the website and /forum/ is a folder as is /site-feedback/ and /photo-test-thread-only/ and 81736-2.html is the page which is fetched from the site.
slightly complicated s4 is a computer which hosts some of the site anyway in /uploads/images/original/ is a picture called 24215.jpg and your browser will load the original full sized image.
not the scaled down image which is generated for the forum post.
now what you could do with any image on this site (or anysite ) is right click on an image and copy image location and paste it into the address bar then deleting anything to the right of .jpg
Some sites disable right clicking or set an image as a background or put an unvisable see through image on top to try to stop you copying an image but if you really want a particular image you can choose the file menu in the browser and save page as and this will download all the files that make up the page .including the file which is the image you wanted.