task 3

src/imagefilters/ImageFilters.scala

@@ -4,16 +4,18 @@ package imagefilters
  * This class implements the various image filters
  */
 object ImageFilters {
-
-  def duplicate(a: Array[Array[Int]]): Array[Array[Int]] = {
-    val height: Int = a.length
-    val width: Int = if (height == 0) 0 else a(0).length
-    val res: Array[Array[Int]] = Array.ofDim(height, width)
+  def filter(src: Array[Array[Int]], func: (Int, Int, Int) => Int): Array[Array[Int]] = {
+    val height: Int = src.length
+    val width: Int = if (height == 0) 0 else src(0).length
+    val dst: Array[Array[Int]] = Array.ofDim(height, width)
     for (y: Int <- 0 until height) {
       for (x: Int <- 0 until width) {
-        res(y)(x) = a(y)(x)
+        dst(y)(x) = func(src(y)(x), x, y)
       }
     }
-    return res
+    return dst
   }
+
+  def duplicate(a: Array[Array[Int]]): Array[Array[Int]] = filter(a, (value, x, y) => value)
+  def threshold(a: Array[Array[Int]], thresh: Int): Array[Array[Int]] = filter(a, (value, x, y) => if (value > thresh) 255 else 0)
 }

src/imagefilters/ImageProcessingApp.scala

@@ -7,8 +7,11 @@ object ImageProcessingApp extends App {
 	val imageFile = "./res/collins_eileen.png"
 	val org = new ImageGraphics(imageFile, "Original", -500, -250)
 	val dest = new ImageGraphics(imageFile, "Duplicate", 0, -250)
+	val thresh = new ImageGraphics(imageFile, "Threshold", -500, 250)
 
     // Simple copy and display
 	val newPixels = ImageFilters.duplicate(org.getPixelsBW())
 	dest.setPixelsBW(newPixels)
+
+	thresh.setPixelsBW(ImageFilters.threshold(newPixels, 128))
 }