From 593aa26451aff1e05e53f1449193dc0d226ee005 Mon Sep 17 00:00:00 2001
From: Ger Hobbelt <ger@hobbelt.com>
Date: Sat, 5 Aug 2023 16:20:40 +0200
Subject: [PATCH] added example code from
 https://github.com/tesseract-ocr/tesseract/pull/4070 : GetGradient()

---
 src/examples/get-page-gradient.cpp | 58 ++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/examples/get-page-gradient.cpp

diff --git a/src/examples/get-page-gradient.cpp b/src/examples/get-page-gradient.cpp
new file mode 100644
index 0000000000..d5a4c23deb
--- /dev/null
+++ b/src/examples/get-page-gradient.cpp
@@ -0,0 +1,58 @@
+// example as part of https://github.com/tesseract-ocr/tesseract/pull/4070
+
+#include <allheaders.h>
+#include <tesseract/baseapi.h>
+
+
+#if defined(BUILD_MONOLITHIC)
+#  define main     tesseract_get_page_gradient_main
+
+#  ifdef __cplusplus
+extern "C" {
+#  endif
+
+int main(int argc, const char **argv);
+
+#  ifdef __cplusplus
+}
+#  endif
+
+#endif
+
+int main(int argc, const char **argv) {
+  tesseract::TessBaseAPI *api = new tesseract::TessBaseAPI();
+  // Initialize tesseract-ocr with English, without specifying tessdata path
+  if (api->InitSimple(NULL, "eng")) {
+    fprintf(stderr, "Could not initialize tesseract.\n");
+    return 1;
+  }
+
+  // Open input image with leptonica library
+  std::string filepath;
+  if (argc > 1 && argv[1] != nullptr) {
+    filepath = argv[1];
+  }
+  if (filepath.empty()) {
+    filepath = "rotate_image.png";
+  }
+  Pix *image = pixRead(filepath.c_str());
+  if (!image) {
+    fprintf(stderr, "Could not open image file: %s\n", filepath.c_str());
+    return 1;
+  }
+
+  api->SetImage(image);
+
+  // Find lines, get average gradient
+  api->AnalyseLayout();
+  float gradient = api->GetGradient();
+
+  printf("Average Gradient: %f\n", gradient);
+
+  // Destroy used object and release memory
+  api->End();
+  delete api;
+  pixDestroy(&image);
+
+  return 0;
+}