Image Slicing was Re: [oclug]for the mac / linux fans

[daniel quinn]

On January 13, 2003 09:25 am, Pat Gilliland wrote:
> Brad's discussion of image slicing make sense to me.  Would you please
> elaborate.
>
> Shad Young wrote:
> > You really have no idea what you're talking about, do you Brad? Do you
> > just make this stuff up as you go along?
> >
> > Shad

brad is quite right.  it's entirely possible to select a section, copy, and 
paste it into a new document, compress and save it to your liking.  this is, 
after all how photoshop 4 worked.  but then macromedia introduced their 
"fireworks" graphical editor, and while it lacked the powers of photoshop 
(masking wasn't pretty, and useability in other areas was lacking). it had 
this really handy tool that let you cut up your image into pieces any size 
you like so you could compress your web layout any way you like.

brad doesn't know what he's talking about when he goes on ranting about how 
you don't need to cut up an layout to get it on the web and heres why:

1.
to the human eye, the page *does* load faster.  if you're waiting for a page 
to load, you're much more likely to leave if you're waiting 30seconds for a 
single image to load.  but if parts of that image load in different areas, 
the user waits longer 'cause it appears that the site is loading faster.

2.
image compression is diversified for a reason.  images with a small number of 
"flat" colours (as opposed to gradients) compress better under .gif than 
under .jpeg whereas jpeg compression is best used for photo-quality or 
gradient images.  if you have a web layout that employs both, hacking it up 
into little bits is the best way to go.

3.
this chopping up also allows you to save your compression and dimension 
settings for each "piece" of your layout.  say your header has 3parts to it, 
2jpeg, 1gif compressed.  if you make any changes, no matter how minor, you're 
looking at having to "select, copy, paste, compress, save" for each of those 
three... and lets just hope you got the right dimensions for each piece.  
guides sometimes can get crazy-confusing in layouts that include up to 50 
different chunks.

4.
there's one more option that i'm sure he forgot, and that's simple menu 
buttons etc.  each section of a menu (if an image) needs to be cut up into 
menu elements in order to allow you to attach a link to each menu item.  yes, 
this can be done with an image map, but then you run into the "big, slow 
loading image" problem mentioned in #1.

this is what i do for a living, please don't start commenting on how i don't 
know what i'm talking about when this is definately my field.