ClientToBitmap example for C++Builder
void __fastcall TForm1::LEADImage1MouseDown(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
int BitmapX;
int BitmapY;
BitmapX= X;
BitmapY= Y;
LEADImage1->ClientToBitmap ( BitmapX, BitmapY );
//Change that pixel to White
LEADImage1->Pixel[LEADImage1->ConvertX][LEADImage1->ConvertY]= RGB(255, 255, 255 ) ;
}