June 2018 Update

Task/Bitmap-Flood-fill/Julia/bitmap-flood-fill.julia

@@ -0,0 +1,46 @@
+using Images, FileIO
+
+function floodfill!(img::Matrix{<:Color}, initnode::CartesianIndex{2}, target::Color, replace::Color)
+    img[initnode] != target && return img
+    # constants
+    north = CartesianIndex(-1,  0)
+    south = CartesianIndex( 1,  0)
+    east  = CartesianIndex( 0,  1)
+    west  = CartesianIndex( 0, -1)
+
+    queue = [initnode]
+    while !isempty(queue)
+        node = pop!(queue)
+        if img[node] == target
+            wnode = node
+            enode = node + east
+        end
+        # Move west until color of node does not match target color
+        while checkbounds(Bool, img, wnode) && img[wnode] == target
+            img[wnode] = replace
+            if checkbounds(Bool, img, wnode + north) && img[wnode + north] == target
+                push!(queue, wnode + north)
+            end
+            if checkbounds(Bool, img, wnode + south) && img[wnode + south] == target
+                push!(queue, wnode + south)
+            end
+            wnode += west
+        end
+        # Move east until color of node does not match target color
+        while checkbounds(Bool, img, enode) && img[enode] == target
+            img[enode] = replace
+            if checkbounds(Bool, img, enode + north) && img[enode + north] == target
+                push!(queue, enode + north)
+            end
+            if checkbounds(Bool, img, enode + south) && img[enode + south] == target
+                push!(queue, enode + south)
+            end
+            enode += east
+        end
+    end
+    return img
+end
+
+img = Gray{Bool}.(load("data/unfilledcircle.png"))
+floodfill!(img, CartesianIndex(100, 100), Gray(false), Gray(true))
+save("data/filledcircle.png", img)