how to use adobe illustrator live trace ?

how to use adobe illustrator live trace ?

Well, the main use for live trace is the pixel to vector transform. Anything - photos, logos or anything using pixels, will never be automated vector as you paste it into illustrator (as you might know from earlier testing etc.) The live trace tool simulates the photo you've pasted in into a vector format. So, you have different presets (I guess you can download more if none of the basics one are pleasing you), and they are for different purposes. I recommend just playing around till you find the right one for your purpose, but the presets has names to whatever they are made to be used for - for example "high fidelty photo" is for photographs you want to turn into a vector based product of the photograph you got. "3 colors" will do exactly what it names say. If you got a picture with tons of colors, it will simulate the same picture only using 3 of them (the most frequent in your photo, i guess).
hopefully you will know the purpose of it and play with it!

PS. In most cases - if theres a logo or symbol, this will not work good. Use the pen tool for that, makes the quality way better.
good luck!

add the photo to work space and then use this panel.  trace.png   6.85KB   16 downloads
hope I helped

Thanks for sharing!

Tip, use expand object after livetrace to make each color section its own vector