Image Data pre-processing. about ml-examples

[navsuda]

@mansiag05,
It would be simple mean subtraction (i.e. 1). If you use mean.binaryproto (e.g. here), that would be pixel-wise subtraction (i.e. image_data[i]-mean_data[i]). If you use channel-wise mean transform (e.g. here, then you can do image_data[i]-mean_data[0].

[mansiag05]

Thank you for your response @navsuda

The doubt that I have now is, if we quantize the given caffe model cifar10_m7_train_test.prototxt using the given script nn_quantizer, the output says that the input will be of the form

Input: data Q8.-1(scaling factor:0.5)

According to this line, would it not be required to do
mean subtraction (i.e. image_data[i] - mean_data[i]) * power(2,-1),

to make the input of the form Q(8,-1) rather than the original Q(7,0)?