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+///////////////////////////////////////////////////////////////////////
+// File:        cjkpitch.h
+// Description: Code to determine fixed pitchness and the pitch if fixed,
+//              for CJK text.
+// Copyright 2011 Google Inc. All Rights Reserved.
+// Author: takenaka@google.com (Hiroshi Takenaka)
+// Created:     Mon Jun 27 12:48:35 JST 2011
+//
+// 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 CJKPITCH_H_
+#define CJKPITCH_H_
+
+#include          "blobbox.h"
+
+namespace tesseract {
+
+// Function to test "fixed-pitchness" of the input text and estimating
+// character pitch parameters for it, based on CJK fixed-pitch layout
+// model.
+//
+// This function assumes that a fixed-pitch CJK text has following
+// characteristics:
+//
+// - Most glyphs are designed to fit within the same sized square
+//   (imaginary body). Also they are aligned to the center of their
+//   imaginary bodies.
+// - The imaginary body is always a regular rectangle.
+// - There may be some extra space between character bodies
+//   (tracking).
+// - There may be some extra space after punctuations.
+// - The text is *not* space-delimited. Thus spaces are rare.
+// - Character may consists of multiple unconnected blobs.
+//
+// And the function works in two passes.  On pass 1, it looks for such
+// "good" blobs that has the pitch same pitch on the both side and
+// looks like a complete CJK character. Then estimates the character
+// pitch for every row, based on those good blobs. If we couldn't find
+// enough good blobs for a row, then the pitch is estimated from other
+// rows with similar character height instead.
+//
+// Pass 2 is an iterative process to fit the blobs into fixed-pitch
+// character cells. Once we have estimated the character pitch, blobs
+// that are almost as large as the pitch can be considered to be
+// complete characters. And once we know that some characters are
+// complete characters, we can estimate the region occupied by its
+// neighbors. And so on.
+//
+// We repeat the process until all ambiguities are resolved. Then make
+// the final decision about fixed-pitchness of each row and compute
+// pitch and spacing parameters.
+//
+// (If a row is considered to be proportional, pitch_decision for the
+// row is set to PITCH_CORR_PROP and the later phase
+// (i.e. Textord::to_spacing()) should determine its spacing
+// parameters)
+//
+// This function doesn't provide all information required by
+// fixed_pitch_words() and the rows need to be processed with
+// make_prop_words() even if they are fixed pitched.
+void compute_fixed_pitch_cjk(ICOORD page_tr,               // top right
+                             TO_BLOCK_LIST *port_blocks);  // input list
+
+} // namespace tesseract
+
+#endif  // CJKPITCH_H_