If you want to select the URL's of all the images on a website you can select all the image tags and then get the absolute URL's.
Example:
String html = "http://www.bbc.co.uk";
Document doc = Jsoup.connect(html).get();
Elements titles = doc.select("img");
for (Element e : titles) {
System.out.println(e.absUrl("src"));
}
which will grab all the <img>
elements and present it, such as
http://sa.bbc.co.uk/bbc/bbc/s?name=SET-COUNTER&pal_route=index&ml_name=barlesque&app_type=web&language=en-GB&ml_version=0.16.1&pal_webapp=wwhp&blq_s=3.5&blq_r=3.5&blq_v=default-worldwide
http://static.bbci.co.uk/frameworks/barlesque/2.50.2/desktop/3.5/img/blq-blocks_grey_alpha.png
http://static.bbci.co.uk/frameworks/barlesque/2.50.2/desktop/3.5/img/blq-search_grey_alpha.png
http://news.bbcimg.co.uk/media/images/69139000/jpg/_69139104_69139103.jpg
http://news.bbcimg.co.uk/media/images/69134000/jpg/_69134575_waynerooney1.jpg
If you only want the .JPG files, tell the selector that by including
Elements titles = doc.select("img[src$=.jpg]");
which result in only parsing the .JPG-urls.