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Diffstat (limited to 'tesseract/src/lstm/maxpool.cpp')
-rw-r--r-- | tesseract/src/lstm/maxpool.cpp | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/tesseract/src/lstm/maxpool.cpp b/tesseract/src/lstm/maxpool.cpp new file mode 100644 index 00000000..5083dd96 --- /dev/null +++ b/tesseract/src/lstm/maxpool.cpp @@ -0,0 +1,80 @@ +/////////////////////////////////////////////////////////////////////// +// File: maxpool.cpp +// Description: Standard Max-Pooling layer. +// Author: Ray Smith +// +// (C) Copyright 2014, Google Inc. +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// http://www.apache.org/licenses/LICENSE-2.0 +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +/////////////////////////////////////////////////////////////////////// + +#include "maxpool.h" + +namespace tesseract { + +Maxpool::Maxpool(const char* name, int ni, int x_scale, int y_scale) + : Reconfig(name, ni, x_scale, y_scale) { + type_ = NT_MAXPOOL; + no_ = ni; +} + +// Reads from the given file. Returns false in case of error. +bool Maxpool::DeSerialize(TFile* fp) { + bool result = Reconfig::DeSerialize(fp); + no_ = ni_; + return result; +} + +// Runs forward propagation of activations on the input line. +// See NetworkCpp for a detailed discussion of the arguments. +void Maxpool::Forward(bool debug, const NetworkIO& input, + const TransposedArray* input_transpose, + NetworkScratch* scratch, NetworkIO* output) { + output->ResizeScaled(input, x_scale_, y_scale_, no_); + maxes_.ResizeNoInit(output->Width(), ni_); + back_map_ = input.stride_map(); + + StrideMap::Index dest_index(output->stride_map()); + do { + int out_t = dest_index.t(); + StrideMap::Index src_index(input.stride_map(), dest_index.index(FD_BATCH), + dest_index.index(FD_HEIGHT) * y_scale_, + dest_index.index(FD_WIDTH) * x_scale_); + // Find the max input out of x_scale_ groups of y_scale_ inputs. + // Do it independently for each input dimension. + int* max_line = maxes_[out_t]; + int in_t = src_index.t(); + output->CopyTimeStepFrom(out_t, input, in_t); + for (int i = 0; i < ni_; ++i) { + max_line[i] = in_t; + } + for (int x = 0; x < x_scale_; ++x) { + for (int y = 0; y < y_scale_; ++y) { + StrideMap::Index src_xy(src_index); + if (src_xy.AddOffset(x, FD_WIDTH) && src_xy.AddOffset(y, FD_HEIGHT)) { + output->MaxpoolTimeStep(out_t, input, src_xy.t(), max_line); + } + } + } + } while (dest_index.Increment()); +} + +// Runs backward propagation of errors on the deltas line. +// See NetworkCpp for a detailed discussion of the arguments. +bool Maxpool::Backward(bool debug, const NetworkIO& fwd_deltas, + NetworkScratch* scratch, + NetworkIO* back_deltas) { + back_deltas->ResizeToMap(fwd_deltas.int_mode(), back_map_, ni_); + back_deltas->MaxpoolBackward(fwd_deltas, maxes_); + return true; +} + + +} // namespace tesseract. |