CIS 228 The Internet 1/13/11 Images

URL's Uniform Resource Locator protocol://domain:port/path#fragment Protocol – a scheme for exchanging information http (hypertext transfer protocol), ftp, etc. Domain – identifies a server Port – optional number for the protocol to use Path – specifies a file on the server Fragment – specifies a location within the file

Domain Names Top level: com, org, net, edu, mil, … Second level: google.com, cuny.edu, … You can acquire these Provided by Domain Name Registrars ($10/year) Go Daddy, eNom, Tucows, Melbourne IT, Key-Systems Deeper level: www.abc.com, lehman.cuny.edu Administered by the second level name owner Typically, the first name identifies a machine media.lehman.cuny.edu

The Image Element An inline element that identifies an image to display Tag: <img> (an empty element, no closing tag) src attribute, where to find the image Relative path to a local file, or Uniform Resource Locator alt attribute, text to display when src can't be found width attribute, coveys size information to the browser height attribute, also resizes the image Use width (and height) to inform the browser Not to resize an image

Image Processing Software Adobe Photoshop – the gold standard GIMP – open source Photoshop replacement Image Converter – change image file format Pixlr – web based image processor Splashup – web based image processor

Common Image Formats jpg gif (depricated ??) png psd Variable, lossy data compression Good for photos (lots of colors) gif (depricated ??) Good for logos (small number or colors) Transparency png Newer format with transparency (replacing gif ?) psd Proprietary, Adobe Photoshop format