task 5

src/imagefilters/ImageFilters.scala

@@ -50,4 +50,13 @@ object ImageFilters {
       }
     })
   }
+
+  def edges(a: Array[Array[Int]]): Array[Array[Int]] = filter(a, (value, x, y, width, height) => {
+    if (x == 0 || x == width - 1 || y == 0 || y == height - 1) value
+    else {
+      val dx: Int = a(y)(x+1) - a(y)(x-1)
+      val dy: Int = a(y+1)(x) - a(y-1)(x)
+      Math.sqrt(dx*dx + dy*dy).toInt
+    }
+  })
 }