Mean file "mean.ppm" of deepstream

About mean value 128, what i am saying, when input data doing mean value subtraction, for DIGITs trained model, it will pixel by pixel subtract mean value data, which is from meam.ppm, but for pytorch, or tensorflow, it usually ditectly substract 128.
and from the picture, you are using original resnet18 classifier model? we have mean.ppm in the package.