--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/tesseract/src/classify/intfx.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,68 @@
+/******************************************************************************
+ **  Filename:    intfx.h
+ **  Purpose:     Interface to high level integer feature extractor.
+ **  Author:      Robert Moss
+ **  History:     Tue May 21 15:51:57 MDT 1991, RWM, Created.
+ **
+ **  (c) Copyright Hewlett-Packard Company, 1988.
+ ** 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 INTFX_H
+#define INTFX_H
+
+#include "blobs.h"
+#include "intproto.h"
+#include "normalis.h"
+
+#include <cmath>
+
+namespace tesseract {
+
+class DENORM;
+
+class TrainingSample;
+
+struct INT_FX_RESULT_STRUCT {
+  int32_t Length;       // total length of all outlines
+  int16_t Xmean, Ymean; // center of mass of all outlines
+  int16_t Rx, Ry;       // radius of gyration
+  int16_t NumBL, NumCN; // number of features extracted
+  int16_t Width;        // Width of blob in BLN coords.
+  uint8_t YBottom;      // Bottom of blob in BLN coords.
+  uint8_t YTop;         // Top of blob in BLN coords.
+};
+
+// The standard feature length
+const double kStandardFeatureLength = 64.0 / 5;
+
+/**----------------------------------------------------------------------------
+          Public Function Prototypes
+----------------------------------------------------------------------------**/
+TESS_API
+void InitIntegerFX();
+
+// Returns a vector representing the direction of a feature with the given
+// theta direction in an INT_FEATURE_STRUCT.
+TESS_API
+FCOORD FeatureDirection(uint8_t theta);
+
+// Generates a TrainingSample from a TBLOB. Extracts features and sets
+// the bounding box, so classifiers that operate on the image can work.
+// TODO(rays) BlobToTrainingSample must remain a global function until
+// the FlexFx and FeatureDescription code can be removed and LearnBlob
+// made a member of Classify.
+TrainingSample *BlobToTrainingSample(const TBLOB &blob, bool nonlinear_norm,
+                                     INT_FX_RESULT_STRUCT *fx_info,
+                                     std::vector<INT_FEATURE_STRUCT> *bl_features);
+
+} // namespace tesseract
+
+#endif