Turning off compilation for GPU detector by default.

Compiler flag can be used to re-enable it

src/openalpr/detection/detectorcuda.cpp

@@ -20,6 +20,7 @@
 
 #include "detectorcuda.h"
 
+#if COMPILE_GPU
 
 using namespace cv;
 using namespace std;
@@ -137,4 +138,6 @@ namespace alpr
 
   }
 
-}
+}
+
+#endif

src/openalpr/detection/detectorcuda.h

@@ -20,6 +20,8 @@
 #ifndef OPENALPR_DETECTORCUDA_H
 #define	OPENALPR_DETECTORCUDA_H
 
+#if COMPILE_GPU
+
 #include <stdio.h>
 #include <iostream>
 #include <vector>
@@ -50,6 +52,8 @@ namespace alpr
   };
 
 }
-  
+
+#endif 
+
 #endif	/* OPENALPR_DETECTORCUDA_H */
 

src/openalpr/detection/detectorfactory.cpp

@@ -11,7 +11,13 @@ namespace alpr
     }
     else if (config->gpu_mode == 1)
     {
+      #if COMPILE_GPU
       return new DetectorCUDA(config);
+      #else
+      std::cerr << "Error: GPU detector requested, but GPU extensions are not compiled.  " <<
+              "Add COMPILE_GPU=1 to the compiler definitions to enable GPU compilation." <<
+              std::endl;
+      #endif
     }
   }