Refactor data_transform to allow datum, cv:Mat and Blob transformation

Move data_mean into the data_transform class to facilitate data transformation. 
This way Data layers don't need to hold it and pass it all the time. 

@sguada I think it has something to do with what's included where though.
There can be cv::Mat in the code, but only when compiled for CPU by g++ /
clang++ and not when compiled by NVCC for GPU.

On Thu, Sep 25, 2014 at 10:07 AM, Sergio Guadarrama <
notifications@github.com> wrote:

> In include/caffe/data_transformer.hpp:
>
> >     * @param datum
> >     *    Datum containing the data to be transformed.
> > -   * @param mean
> > +   * @param datum_vector
>
> Then I'm really confused, because before we were also using opencv::Mat
> and it was working, isn't it? Sergio 2014-09-25 10:04 GMT-07:00 Evan
> Shelhamer <notifications@github.com>:
> … <#148adc848d3ad841_>
>  In include/caffe/data_transformer.hpp: > * @param
> <https://github.com/param> datum > * Datum containing the data to be
> transformed. > - * @param <https://github.com/param> mean > + * @param
> <https://github.com/param> datum_vector Looking over the crash it looks
> like NVCC just hates OpenCV's mat.hpp. … <#148adc5bc6bc9de0_> On Thursday,
> September 25, 2014, Sergio Guadarrama < notifications@github.com> wrote:
> In include/caffe/data_transformer.hpp: > * @param
> <https://github.com/param> <https://github.com/param> datum > * Datum
> containing the data to be transformed. > - * @param
> <https://github.com/param> <https://github.com/param> mean > + * @param
> <https://github.com/param> <https://github.com/param> datum_vector Sure I
> will replicate the definition for each case — Reply to this email directly
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> https://github.com/BVLC/caffe/pull/1070/files#r18044767>. — Reply to this
> email directly or view it on GitHub <
> https://github.com/BVLC/caffe/pull/1070/files#r18044855>.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/BVLC/caffe/pull/1070/files#r18045025>.
>