--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/tesseract/src/lstm/input.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,109 @@
+///////////////////////////////////////////////////////////////////////
+// File:        input.h
+// Description: Input layer class for neural network implementations.
+// 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.
+///////////////////////////////////////////////////////////////////////
+
+#ifndef TESSERACT_LSTM_INPUT_H_
+#define TESSERACT_LSTM_INPUT_H_
+
+#include "network.h"
+
+namespace tesseract {
+
+class ScrollView;
+
+class Input : public Network {
+public:
+  TESS_API
+  Input(const std::string &name, int ni, int no);
+  TESS_API
+  Input(const std::string &name, const StaticShape &shape);
+  ~Input() override = default;
+
+  std::string spec() const override {
+    return std::to_string(shape_.batch()) + "," +
+           std::to_string(shape_.height()) + "," +
+           std::to_string(shape_.width()) + "," +
+           std::to_string(shape_.depth());
+  }
+
+  // Returns the required shape input to the network.
+  StaticShape InputShape() const override {
+    return shape_;
+  }
+  // Returns the shape output from the network given an input shape (which may
+  // be partially unknown ie zero).
+  StaticShape OutputShape(
+      [[maybe_unused]] const StaticShape &input_shape) const override {
+    return shape_;
+  }
+  // Writes to the given file. Returns false in case of error.
+  // Should be overridden by subclasses, but called by their Serialize.
+  bool Serialize(TFile *fp) const override;
+  // Reads from the given file. Returns false in case of error.
+  bool DeSerialize(TFile *fp) override;
+
+  // Returns an integer reduction factor that the network applies to the
+  // time sequence. Assumes that any 2-d is already eliminated. Used for
+  // scaling bounding boxes of truth data.
+  // WARNING: if GlobalMinimax is used to vary the scale, this will return
+  // the last used scale factor. Call it before any forward, and it will return
+  // the minimum scale factor of the paths through the GlobalMinimax.
+  int XScaleFactor() const override;
+
+  // Provides the (minimum) x scale factor to the network (of interest only to
+  // input units) so they can determine how to scale bounding boxes.
+  void CacheXScaleFactor(int factor) override;
+
+  // Runs forward propagation of activations on the input line.
+  // See Network for a detailed discussion of the arguments.
+  void Forward(bool debug, const NetworkIO &input,
+               const TransposedArray *input_transpose, NetworkScratch *scratch,
+               NetworkIO *output) override;
+
+  // Runs backward propagation of errors on the deltas line.
+  // See Network for a detailed discussion of the arguments.
+  bool Backward(bool debug, const NetworkIO &fwd_deltas,
+                NetworkScratch *scratch, NetworkIO *back_deltas) override;
+  // Creates and returns a Pix of appropriate size for the network from the
+  // image_data. If non-null, *image_scale returns the image scale factor used.
+  // Returns nullptr on error.
+  /* static */
+  static Image PrepareLSTMInputs(const ImageData &image_data,
+                                 const Network *network, int min_width,
+                                 TRand *randomizer, float *image_scale);
+  // Converts the given pix to a NetworkIO of height and depth appropriate to
+  // the given StaticShape:
+  // If depth == 3, convert to 24 bit color, otherwise normalized grey.
+  // Scale to target height, if the shape's height is > 1, or its depth if the
+  // height == 1. If height == 0 then no scaling.
+  // NOTE: It isn't safe for multiple threads to call this on the same pix.
+  static void PreparePixInput(const StaticShape &shape, const Image pix,
+                              TRand *randomizer, NetworkIO *input);
+
+private:
+  void DebugWeights() override {
+    tprintf("Must override Network::DebugWeights for type %d\n", type_);
+  }
+
+  // Input shape determines how images are dealt with.
+  StaticShape shape_;
+  // Cached total network x scale factor for scaling bounding boxes.
+  int cached_x_scale_;
+};
+
+} // namespace tesseract.
+
+#endif // TESSERACT_LSTM_INPUT_H_