task 4.2

src/imagefilters/ImageFilters.scala

@@ -21,7 +21,7 @@ object ImageFilters {
 
   def duplicate(a: Array[Array[Int]]): Array[Array[Int]] = filter(a, (value) => value)
   def threshold(a: Array[Array[Int]], thresh: Int): Array[Array[Int]] = filter(a, (value) => if (value > thresh) 255 else 0)
-  def mean(a: Array[Array[Int]]): Array[Array[Int]] = filter(a, (value: Int, x, y, width, height) => {
+  def mean(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 {
       var avg: Double = 0
@@ -33,4 +33,21 @@ object ImageFilters {
       (avg/9.0).toInt
     }
   })
+  def mean(a: Array[Array[Int]], radius: Int): Array[Array[Int]] = {
+    if (radius < 0) throw new IllegalArgumentException("radius must be >= 0")
+    val diameter: Int = 2 * radius + 1
+
+    filter(a, (value, x, y, width, height) => {
+      if (x <= radius - 1 || x >= width - radius || y <= radius - 1 || y >= height - radius) value
+      else {
+        var avg: Double = 0
+        for (dy: Int <- -radius to radius) {
+          for (dx: Int <- -radius to radius) {
+            avg += a(y+dy)(x+dx)
+          }
+        }
+        (avg/(diameter * diameter)).toInt
+      }
+    })
+  }
 }

src/imagefilters/ImageProcessingApp.scala

@@ -17,4 +17,7 @@ object ImageProcessingApp extends App {
 
 	val mean = new ImageGraphics("./res/imageProcessing.jpg", "Mean", 0, 250)
 	mean.setPixelsBW(ImageFilters.mean(mean.getPixelsBW()))
+
+	val mean2 = new ImageGraphics("./res/imageProcessing.jpg", "Mean 2", 250, 250)
+	mean2.setPixelsBW(ImageFilters.mean(mean2.getPixelsBW(), 4))
 }