3 Replies Latest reply on May 26, 2011 2:07 PM by Takashi Morifusa

    Transparency - 8bit w/ alpha vs. 32bit

    jethrodesign Level 1

      Hi, we are designing a pretty graphics heavy site right now. It's a very rough, organic design, and uses transparency quite a bit (mostly solid color boxes letting the background texture show through a bit).


      So we know we'll have to do some serious optimization to make sure this site isn't a complete slug. We plan on using sprites as much as possible. But we need to figure out how to approach all the transparency.


      - Can anyone verify from experience the file-size savings you would get if saving relatively simple graphics (mostly solid tones, large color blocks, type, etc.) with transparency as 8bit w/ alpha transparency vs. full 32bit??


      We are not really concerned about the IE6 compatibility aspect of it, just the file-size savings part.


      The main reason for the question is that the design is done in Illustrator CS4 and we would love to just export the slices from there. Illustrator does support full 32bit PNGs (calls it PNG-24 of course). But we do have a copy of Fireworks CS4 that we don't use too much. Just want to make sure it will be worth all the effort of properly bringing all the elements in from Illustrator and making sure nothing gets messed up in the migration.



        • 1. Re: Transparency - 8bit w/ alpha vs. 32bit
          Linda Nicholls Level 4

          Exporting them as 8 bit PNG files with Alpha transparency would make a huge difference in file size, in almost all cases. You'll have to experiment with it a bit to see if the difference in the quality of the images will work for you.

          • 2. Re: Transparency - 8bit w/ alpha vs. 32bit
            jethrodesign Level 1

            Thanks. We did end up using Fireworks to create a large sprite of all the Home page background elements (some will be used elsewhere). We were able to get a roughly 1800px square file with the equivalent of what would have been 34 individual grahpics saved as one 100kb image sprite! Considering all elements had partial opacity, and a lot had soft glows and/or drop-shadows, that's a HUGE savings!


            UNFORTUNATELY, Fireworks CS4 slowed to an absolute crawl on my ol' G5 Dual 2Ghz Mac Pro (with 6GB RAM). Even just selecting and element would cause a few seconds of spinning beachball. So I had to 'borrow' my bosses newer MacBook Pros to get anything done (not ideal!). And even with that, I had to install a demo of Fireworks CS5 for it to really work without a lot of delays.


            And the Illustrator CS4 file DID NOT come in very nicely either. I pretty much had to rebuild most of it from scratch. According to the Adobe documentation, most everything I was doing 'should' have come in fine (I wasn't really doing anything that was listed as not compatible). Nice in theory...


            It's too bad Fireworks seems to be Adobes ugly stepchild that doesn't get much attention. If they fixed performance and import issues, added a useful color/swatches implementation (from Illustrator/InDesign), and added at least simple paragraph/character styles (again - Illustrator/InDesign), we would definitely love to use this for website comps and graphics creation instead of Illustrator. But for now, unless we absolutely need Fireworks' 8-bit PNGs w/ alpha-transparency, we'll stick with Illustrator. It's too bad, I'm originally a Macromedia guy and was using Fireworks back in v.2/3.

            • 3. Re: Transparency - 8bit w/ alpha vs. 32bit
              Takashi Morifusa Employee Moderator

              When you importing Illustrator CS4 file, what kind of element you are having issue to import?

              Regarding performance,majority of CS5 products drop suppot G5.


              Do you see particular area of performance issue on you Boss's MacBookPro?