Switch to the libvips crop strategy implementations

src/operations.h

@@ -72,22 +72,6 @@ namespace sharp {
    */
   VImage Sharpen(VImage image, double const sigma, double const flat, double const jagged);
 
-  /*
-    Crop strategy functors
-  */
-  struct EntropyStrategy {
-    double operator()(VImage image);
-  };
-  struct AttentionStrategy {
-    double operator()(VImage image);
-  };
-
-  /*
-    Calculate crop area based on given strategy (Entropy, Attention)
-  */
-  std::tuple<int, int> Crop(
-    VImage image, int const outWidth, int const outHeight, std::function<double(VImage)> strategy);
-
   /*
     Insert a tile cache to prevent over-computation of any previous operations in the pipeline
   */