document DeconvolutionLayer

include/caffe/vision_layers.hpp

@@ -16,6 +16,10 @@
 
 namespace caffe {
 
+/**
+ * @brief Abstract base class that factors out the BLAS code common to
+ *        ConvolutionLayer and DeconvolutionLayer.
+ */
 template <typename Dtype>
 class BaseConvolutionLayer : public Layer<Dtype> {
  public:
@@ -173,6 +177,20 @@ class ConvolutionLayer : public BaseConvolutionLayer<Dtype> {
   virtual void compute_output_shape();
 };
 
+/**
+ * @brief Convolve the input with a bank of learned filters, and (optionally)
+ *        add biases, treating filters and convolution parameters in the
+ *        opposite sense as ConvolutionLayer.
+ *
+ *   ConvolutionLayer computes each output value by dotting an input window with
+ *   a filter; DeconvolutionLayer multiplies each input value by a filter
+ *   elementwise, and sums over the resulting output windows. In other words,
+ *   DeconvolutionLayer is ConvolutionLayer with the forward and backward passes
+ *   reversed. DeconvolutionLayer reuses ConvolutionParameter for its
+ *   parameters, but they take the opposite sense as in ConvolutionLayer (so
+ *   padding is removed from the output rather than added to the input, and
+ *   stride results in upsampling rather than downsampling).
+ */
 template <typename Dtype>
 class DeconvolutionLayer : public BaseConvolutionLayer<Dtype> {
  public: