+ std::cerr << "xsize " << xsize << " ysize " << ysize << " zsize " << zsize << " samplesPerPixel " << samplesPerPixel
+ << " bitsallocated " << bitsallocated << std::endl;
+ std::cerr << "size " << size << " testedDataSize " << testedDataSize <<
+ std::endl;
+ assert(abs (size-testedDataSize) <= 1 );