Image showing for all different resolution in php

I have a large image with 800X800Px i have to show this image for different-different resolution like for every type o mobile and pc.So this image might not appe开发者_开发问答aring well for small 200X200 resolution mobile. What i should to do it. I can get resolution by the java script.Should i resize image with respect to resolution size ?

Ay idea will be appreciate thanks

Well, you can use Mobile Device Detect (http://detectmobilebrowsers.mobi/), and use the script to make variables...

 require_once('mobile_device_detect.php');
    $mobile = mobile_device_detect();

if($mobile == "ipad"){
    $height = '500';
    $width = '500';
}

etc..