hmm, nothing much. I just wanna contribute some stuff about optimizing PNG's.(i'm using CS3, but there shouldn't be a big difference)How to optimize PNG's(transparency, filesize reduction)(source/TL;DR version is this, via Xyrensic, thanks dude)1.
let's get a png file to optimize, obviously. let's use this one because of it's big file size.(screencap from irfanview) then open in photoshop(duh)
(note that this tutorial is also pplicable when you are making a transparent render or whatnot and saving it in PNG.)2.
now, let's check filesize
>save for web and devices
to see it's original filesize(for comparison)3.
now let's select the non-transparent pixels in the image. do this by CTRL+click
ing the layer thumbnail(alternatively, right click the thumbnail and click Select pixels)
( i already quickmasked this, red color)4.
now exit quick mask mode by pressing the button again/Q
and then select inverse (selection>select inverse/SHIFT+ALT+I
then fill the selection with black(shift+F5).(note that pic shows the fill dialog box AND
the image AFTER
filling with black.5.
invert selection again, then press the add layer mask button.6.
now let's check the filesize!7.
not much eh? let's posterize it then, close the save for web & devices
window then image>adjust>posterize
and change the value to 40(highest quality, lowest filesize reduction) you can lower this, but the lower you set it the worse your image will look. then this time save for web and devices and select PNG-24 then click done
(note that if you're working to optimize a multilayer psd. you have to make a new layer and put it on the top then image>apply image then posterize the layer you created.