Improved the type validation on numpy arrays passed to dlib. The old code

didn't have complete coverage and would let incorrectly typed numpy arrays
through.

dlib/python/numpy.h

@@ -14,21 +14,59 @@ namespace py = pybind11;
 
 // ----------------------------------------------------------------------------------------
 
-template <typename T>
+template <typename TT>
 void validate_numpy_array_type (
     const py::object& obj
 )
 {
     const char ch = obj.attr("dtype").attr("char").cast<char>();
 
-    if (dlib::is_same_type<T,double>::value && ch != 'd')
-        throw dlib::error("Expected numpy.ndarray of float64");
-    if (dlib::is_same_type<T,float>::value && ch != 'f')
-        throw dlib::error("Expected numpy.ndarray of float32");
-    if (dlib::is_same_type<T,dlib::int32>::value && ch != 'i')
-        throw dlib::error("Expected numpy.ndarray of int32");
-    if (dlib::is_same_type<T,unsigned char>::value && ch != 'B')
-        throw dlib::error("Expected numpy.ndarray of uint8");
+    using T = typename dlib::pixel_traits<TT>::basic_pixel_type;
+
+    if (dlib::is_same_type<T,double>::value)
+    {
+        if (ch != 'd')
+            throw dlib::error("Expected numpy.ndarray of float64");
+    }
+    else if (dlib::is_same_type<T,float>::value)
+    {
+        if (ch != 'f')
+            throw dlib::error("Expected numpy.ndarray of float32");
+    }
+    else if (dlib::is_same_type<T,dlib::int16>::value)
+    {
+        if (ch != 'h')
+            throw dlib::error("Expected numpy.ndarray of int16");
+    }
+    else if (dlib::is_same_type<T,dlib::uint16>::value)
+    {
+        if (ch != 'H')
+            throw dlib::error("Expected numpy.ndarray of uint16");
+    }
+    else if (dlib::is_same_type<T,dlib::int32>::value)
+    {
+        if (ch != 'i')
+            throw dlib::error("Expected numpy.ndarray of int32");
+    }
+    else if (dlib::is_same_type<T,dlib::uint32>::value)
+    {
+        if (ch != 'I')
+            throw dlib::error("Expected numpy.ndarray of uint32");
+    }
+    else if (dlib::is_same_type<T,unsigned char>::value)
+    {
+        if (ch != 'B')
+            throw dlib::error("Expected numpy.ndarray of uint8");
+    }
+    else if (dlib::is_same_type<T,signed char>::value)
+    {
+        if (ch != 'b')
+            throw dlib::error("Expected numpy.ndarray of int8");
+    }
+    else
+    {
+        throw dlib::error("validate_numpy_array_type() called with unsupported type.");
+    }
 }
 
 // ----------------------------------------------------------------------------------------