[morphology] add imfill function (#9)

This function can be used to fill objects of a certain size with some specified value.

ImageMorphology/README.md

@@ -26,6 +26,7 @@ bothat
 morphogradient
 morpholaplace
 thinning
+imfill
 ```
 
 ## Documentation

ImageMorphology/src/ImageMorphology.jl

@@ -11,6 +11,7 @@ include("connected.jl")
 
 include("dilation_and_erosion.jl")
 include("thinning.jl")
+include("imfill.jl")
 
 export
     dilate,
@@ -36,7 +37,8 @@ export
 
     # thinning.jl
     thinning,
-    GuoAlgo
+    GuoAlgo,
+    imfill
 
 
 end # module

ImageMorphology/src/imfill.jl

@@ -0,0 +1,43 @@
+"""
+ Image filling Algorithm
+
+ ```
+ filled_img = imfill(img, interval)
+ filled_img = imfill(img, interval, value)
+ filled_img = imfill(img, interval, value, connectivity)
+ ```
+
+ Connected components of an image is found using flood-fill algorithm and returns a copy of
+ the original image after filling objects that falls in the range of interval.
+ For filling objects, represent the holes(part to be filled) with `true` in your array.
+
+
+ Parameters:
+
+  -  img            = Input image (Boolean array type)
+  -  interval       = objects of size in this range will be filled with `false`
+  -  connectivity   = connectivity takes the same values as in label_components (Default value is 1:ndims(img))
+
+ """
+
+function imfill(img::AbstractArray{Bool}, interval::Tuple{Real,Real}, connectivity::Union{Dims, AbstractVector{Int}, BitArray}=1:ndims(img))
+
+    if interval[1] > interval[2] || interval[1] < 0 || interval[2] < 0
+        throw(DomainError(interval,"Interval must be non-negative and in format (min_range,max_range)"))
+    end
+
+    labels = label_components(img,connectivity)
+
+    count_labels = Dict([(i,count(x->x==i,labels)) for i in unique(labels)])
+
+    new_img = similar(img)
+    for ind in eachindex(img)
+        if img[ind] == true && interval[1] <= count_labels[labels[ind]] <= interval[2]
+            new_img[ind] = false
+        else
+            new_img[ind] = img[ind]
+        end
+    end
+
+    return new_img
+ end

ImageMorphology/test/imfill.jl

@@ -0,0 +1,45 @@
+@testset "imfill" begin
+    #2 Dimensional case
+    image = Bool.([0 0 0 0 0 0 1 0 0 0
+         	   0 1 1 1 1 1 0 0 0 0
+         	   0 1 0 0 1 1 0 0 0 0
+         	   0 1 1 1 0 1 0 0 0 0
+         	   0 1 1 1 1 1 0 0 0 0
+         	   0 0 0 0 0 0 0 1 1 1
+         	   0 0 0 0 0 0 0 1 0 1
+         	   0 0 0 0 0 0 0 1 1 1
+	       	   0 0 0 0 0 0 0 0 0 0
+	           0 0 0 0 0 0 0 0 0 0])
+    answer = Bool.([0 0 0 0 0 0 1 0 0 0
+         	    0 1 1 1 1 1 0 0 0 0
+         	    0 1 1 1 1 1 0 0 0 0
+         	    0 1 1 1 1 1 0 0 0 0
+         	    0 1 1 1 1 1 0 0 0 0
+         	    0 0 0 0 0 0 0 1 1 1
+         	    0 0 0 0 0 0 0 1 1 1
+         	    0 0 0 0 0 0 0 1 1 1
+		    0 0 0 0 0 0 0 0 0 0
+	            0 0 0 0 0 0 0 0 0 0])
+	@test imfill(.!image, (0,2)) == (.!answer)
+
+	#3 Dimensional case
+	A = zeros(Bool,3,size(image)[1],size(image)[2])
+	A[1,:,:] = image
+	A[2,:,:] = image
+	A[3,:,:] = image
+	B = zeros(Bool,3,size(answer)[1],size(answer)[2])
+	B[1,:,:] = answer
+	B[2,:,:] = answer
+	B[3,:,:] = answer
+	@test imfill(.!A, (0,8)) == (.!B)
+
+	# Complete white image and complete black image case
+	img = zeros(Bool,10,10)
+	@test imfill(img,(0,10)) == img
+	@test imfill(.!img,(0,99)) == .!img
+	# Miscellaneous case
+	img[5,5] = true
+	@test imfill(.!img,(0,10)) == .!img
+	@test imfill(.!img,(0,99)) == zeros(Bool,10,10)	
+end
+

ImageMorphology/test/runtests.jl

@@ -6,4 +6,5 @@ using Test
     include("connected.jl")
     include("dilation_and_erosion.jl")
     include("thinning.jl")
+    include("imfill.jl")
 end