Change sampled_intensities eltype in create_descriptor for FREA…

…K and BRISK (#108)

src/brisk.jl

@@ -89,7 +89,7 @@ function create_descriptor(img::AbstractArray{T, 2}, features::Features, params:
         keypoint = Keypoint(feature)
         checkbounds(Bool, img, keypoint - lim) && checkbounds(Bool, img, keypoint + lim) || continue
         orientation = _brisk_orientation(int_img, keypoint, params.pattern_table[1], params.orientation_weights, params.smoothing_table[1], params.long_pairs)
-        sampled_intensities = T[]
+        sampled_intensities = eltype(int_img)[]
         for (i, p) in enumerate(params.pattern_table[orientation])
             push!(sampled_intensities, ImageFeatures._freak_mean_intensity(int_img, keypoint, p, params.smoothing_table[orientation][i]))
         end

src/freak.jl

@@ -90,7 +90,7 @@ function create_descriptor(img::AbstractArray{T, 2}, keypoints::Keypoints, param
     for k in keypoints
         checkbounds(Bool, img, k - lim) && checkbounds(Bool, img, k + lim) || continue
         orientation = _freak_orientation(int_img, k, params.pattern_table[1], params.orientation_weights, params.smoothing_table[1])
-        sampled_intensities = T[]
+        sampled_intensities = eltype(int_img)[]
         for (i, p) in enumerate(params.pattern_table[orientation])
             push!(sampled_intensities,  _freak_mean_intensity(int_img, k, p, params.smoothing_table[orientation][i]))
         end

test/brisk.jl

@@ -75,3 +75,11 @@ end
     reverse_keypoints_1 = [_reverserotate(m[1], pi / 4, (256, 256)) + CartesianIndex(10, 20) for m in matches]
     @test all(isapprox(rk[1], m[2][1], atol = 4) && isapprox(rk[2], m[2][2], atol = 4) for (rk, m) in zip(reverse_keypoints_1, matches))
 end
+
+@testset "Testing descriptor creation with an image leading to sampled intensities > 1.0" begin
+    img = Gray.(testimage("autumn_leaves"))
+    # Number of contiguous pixels parameter in fastcorner needs to be low, to yield enough corners to hit a sample intensity > 1
+    feats = Features(fastcorners(img, 5, 0.3))
+    brisk_params = BRISK()
+    @test_nowarn create_descriptor(img, feats, brisk_params)
+end

test/freak.jl

@@ -74,3 +74,11 @@ end
     reverse_keypoints_1 = [_reverserotate(m[1], pi / 4, (256, 256)) + CartesianIndex(10, 20) for m in matches]
     @test isapprox(sum(isapprox(rk[1], m[2][1], atol = 4) && isapprox(rk[2], m[2][2], atol = 4) for (rk, m) in zip(reverse_keypoints_1, matches)), length(matches), atol = 2)
 end
+
+@testset "Testing descriptor creation with an image leading to sampled intensities > 1.0" begin
+    img = Gray.(testimage("autumn_leaves"))
+    # Number of contiguous pixels parametre in fastcorner needs to be low, to yield enough corners to hit a sample intensity > 1
+    keypoints = Keypoints(fastcorners(img, 5, 0.3))
+    freak_params = FREAK()
+    @test_nowarn create_descriptor(img, keypoints, freak_params)
+end