Caffe constant multiply layer

Question

How can I define multiply constant layer in Caffe (like MulConstant in Torch). I need to add it predefined const to existing network. Caffe fails to parse my attempt to scale everything by 0.85:

layers {
  name: "caffe.ConstantMul_0"
  type: "Eltwise"
  bottom: "caffe.SpatialConvolution_0"
  top: "caffe.ConstantMul_0"
  eltwise_param {
    op: MUL
    coeff: 0.85
  }
}

Answer 1

It is possible to do with Power Layer, just set up power to 1 and scale to whatever you need:

layer {
  name: "caffe.ConstantMul_1"
  bottom: "caffe.SpatialConvolution_3"
  top: "caffe.ConstantMul_1"
  type: "Power"
  power_param {
    power: 1
    scale: 0.85
    shift: 0
  }
}

Answer 2

Eltwise layer can do three types of operations - PROD, SUM, MAX. You can see more about this here

In your case, the op paramter should be set as PROD.

layers {
  name: "caffe.ConstantMul_0"
  type: "Eltwise"
  bottom: "caffe.SpatialConvolution_0"
  top: "caffe.ConstantMul_0"
  eltwise_param {
    op: MUL
    coeff: 0.85
  }
}