Add tutorial

Author: matt-42

examples/tutorial.cc

@@ -0,0 +1,52 @@
+// Include the header-only library.
+#include <vpp/vpp.hh>
+
+int main()
+{
+  // import vpp into the current namespace.
+  using vpp;
+
+
+  typedef vuchar3 V; // value type.
+  typedef image2d<vuchar3> I; // image type.
+
+  // Declare a 2d image.
+  I img;
+
+  // Load an external image using opencv.
+  img = from_opencv<V>(cv::imread("image.jpg"));
+
+  // Allocate a second image with the same definition domain.
+  I out(img.domain());
+
+  // Iterate on img
+  for (auto pix : img) *pix = *pix * 2;
+
+  // 3x3 box filter on img
+  window<I> row_win(img, {[0, -1], [0, 0], [0, 1]});
+
+  pixel_wise(img, out) << [&] (auto in, auto out)
+  {
+    V sum = V::Zero();
+    for (auto n : row_win(in)) sum += *n;
+    *out = sum / 3;
+  };
+
+  int nr = img.nrows();
+  row_wise(img, out) << [&] (auto in, auto out)
+  {
+    for (int c = 0; c < nr; c++)
+    {
+      vuchar3 sum = vuchar3::Zero();
+      for (auto n : row_win(in)) sum += *n;
+      *out = sum / 3;
+
+      out++;
+      in++;
+    }
+  };
+
+  int dims[] = {100, 200};
+  imageNd<int, 2> img(dims);
+
+}