i am doing a image processing based robot with matlab, but i get stucked when come to the interfacing part with the hardware.
i got 2 question,
1.) can matlab directly communicate to the arduino hardware, how?? software to hardware
2.) then another question is as topic above "can/how matlab interface with arduino software? software to software"
im very new in arduino, hopes someone may help out
Have you seen the section in the Arduino playground titled: MATLAB Interface for Arduino ?
oh im sure i dint see, sorry. but thanks alot yea! 
MOst common is to have Matlab talk to Arduino (or whatever proc) over serial. IN theory you could also talk over ethernet, but I have not seen it yet. The baudrate of the Arduino can be set to 115200 baud - Serial.begin(115200) - according to the reference, but in practice I have used 230400 and 345600 baud too (factor 3 faster)
You can aslo search the forum in the upper right corner. => gives 8 pages of hits (not as much as google) but quite enough I guess.