rink] spatial bin size (defaults to shrink)
     .nOrients     - [6] number of orientation channels
     .softBin      - [0] if true use &quot;soft&quot; bilinear spatial binning
     .useHog       - [0] if true perform 4-way hog normalization/clipping
     .clipHog      - [.2] value at which to clip hog histogram bins
   .pCustom      - parameters for custom channels (optional struct array):
     .enabled      - [1] if true enable custom channel type
     .name         - ['REQ'] custom channel type name
  