On Mon, Aug 10, 2009 at 11:24:40AM -0700, Theresa Mesa wrote: > Interestingly enough, as a learning exercise, I opened an image in > Photoshop, set the image size to 300px x 454px. File size was 399.3K, > regardless of what PPI it was. You were correct, Mike. > > Then I saved the image in Photoshop's "Save for Web and Devices." > Image quality, jpeg, maximum (100). Image size, 300x454. File size, > 93.25K. When I open that image that I saved from "Web and Devices" to > my desktop, it's 399K. But "Save for Web and Devices" just told me the > image was 93K. > > Now we're getting out of the realm of CSS, so I'll take this > interesting question to Adobe's forums.
That's an easy one... 300px x 454px x 3 bytes/px = 408,600px, or 399.0234k of actual, uncompressed image data. Add some headers and metadata, and 399.3k sounds about right as a final uncompressed file size. "Save for Web and Devices" applied jpeg compression to the image, producing a file size smaller than the actual uncompressed image size, but it still has to be decompressed in memory back up to its full 399k to be displayed. -- Dave Sherohman ______________________________________________________________________ css-discuss [cs...@lists.css-discuss.org] http://www.css-discuss.org/mailman/listinfo/css-d List wiki/FAQ -- http://css-discuss.incutio.com/ List policies -- http://css-discuss.org/policies.html Supported by evolt.org -- http://www.evolt.org/help_support_evolt/
