Convert from png to .icns and .ico image using php need clas

I have severals .png file I need class developed in php. If I give like convert('url','width','hieght','ico') or convert('url','width','hieght','icsn') it should convert as I require. Please not that .ico is used for windows icon and .icns for macintosh os. Read carefully before bidding I'm hiring now. Need to done in less than day. Fix budget I'll pay $20 for this. I will give like ('[login to view URL]','250px','250px','ico'); it should convert in .ico wihout loosing transparancy. You can store it temporary because I'll first convert using your class and will allow user's to download from my site. Thanks