How to get the first address of image RGB/16 bit in Hidden plug-in?????

Hi everybody,
May you help me to solve following problems?
1. In function void HiddenPlugin::Write(void) in Hidden plug-in in line: bigError = sPSChannelProcs->ReadPixelsFromLevel(readChannelDesc->port , 0, &currentRect, &pixelMemoryDesc);
a. I base on pixelMemoryDesc parameter, i get the first of image address of each channel. This has problems:
- With image 8 bits, I get address ok. And i shows it by another program is wonderfull - With iamge 16 bits, I get address ok. But i change 16bits to 8bits than show, it has difference from source. I think this address is change when Photoshop shows. How i can get orginal address of image 16 bit.
2. For that problem, can give me example to get orginal address of image 16 bit.

You'd probably be better off asking this in the Photoshop scripting forum.

Most of us here just push pixels and know very little on programming...