IQ Balance

I am new to this group and would appreciate any help. Looking at the rtlsdr driver, I see that there seems to be some code to correct the IQ balance, but I'm only going by the names of functions like "_IQ_Tree" and "_Compare_Cor". The algorithm, if there is one, is not at all clear nor of direct interest, the question is whether or not there is some IQ balance built into the rtlsdr driver and does anyone know how effective (e.g. in terms of image suppression) it is. Then, I'm using this device and software to demonstrate to students the concepts of SDR. So on a related note, if there is some IQ balance correction in the driver, can it be turned off? Changing the driver code is way beyond my ability, but some digging suggests that changing the header file to have #define IMR_TRIAL 0. eliminates a quite complex looking loop of computation that may be the IQ balance scheme. As a newbie I wouldn't attempt this without some positive guidance. It would require a new build of the driver, which I imagine is the same as for the normal case, and then if it can be done, it would be great to illustrate the basic IQ balance of the hardware and the improvement possible with software correction. thanks Richard