--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/tesseract/src/classify/mf.cpp	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,72 @@
+/******************************************************************************
+ ** Filename:    mf.c
+ ** Purpose:     Micro-feature interface to flexible feature extractor.
+ ** Author:      Dan Johnson
+ **
+ ** (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.
+ ******************************************************************************/
+/*----------------------------------------------------------------------------
+          Include Files and Type Defines
+----------------------------------------------------------------------------*/
+#include "mf.h"
+
+#include "featdefs.h"
+#include "mfdefs.h"
+#include "mfx.h"
+
+#include <cmath>
+
+namespace tesseract {
+
+/*----------------------------------------------------------------------------
+              Private Code
+----------------------------------------------------------------------------*/
+/**
+ * Call the old micro-feature extractor and then copy
+ * the features into the new format.  Then deallocate the
+ * old micro-features.
+ * @param Blob  blob to extract micro-features from
+ * @param cn_denorm  control parameter to feature extractor.
+ * @return Micro-features for Blob.
+ */
+FEATURE_SET ExtractMicros(TBLOB *Blob, const DENORM &cn_denorm) {
+  auto features = BlobMicroFeatures(Blob, cn_denorm);
+  if (features.empty()) {
+    return nullptr;
+  }
+  int n = 0;
+  for ([[maybe_unused]] auto &f: features) {
+    ++n;
+  }
+  auto FeatureSet = new FEATURE_SET_STRUCT(n);
+
+  for (auto &f : features) {
+    auto Feature = new FEATURE_STRUCT(&MicroFeatureDesc);
+    for (int i = 0; i < (int)MicroFeatureParameter::MFCount; ++i)
+      Feature->Params[i] = f[i];
+    // Bulge features are deprecated and should not be used. Set to 0.
+    Feature->Params[(int)MicroFeatureParameter::MFBulge1] = 0.0f;
+    Feature->Params[(int)MicroFeatureParameter::MFBulge2] = 0.0f;
+
+#ifndef _WIN32
+    // Assert that feature parameters are well defined.
+    for (int i = 0; i < Feature->Type->NumParams; i++) {
+      ASSERT_HOST(!std::isnan(Feature->Params[i]));
+    }
+#endif
+
+    AddFeature(FeatureSet, Feature);
+  }
+  return FeatureSet;
+} /* ExtractMicros */
+
+} // namespace tesseract