Merge pull request #432 from WilhelmusLab/431-create-dedicated-unshar…

…p_mask-function

feat: unsharp mask

src/normalization.jl

@@ -106,11 +106,50 @@ function imsharpen(
 
     image_equalized_gray = Gray.(image_equalized)
 
-    image_smoothed = imfilter(image_equalized_gray, Kernel.gaussian(smoothing_param))
+    return unsharp_mask(image_equalized_gray, smoothing_param, intensity)
+end
+
+"""
+    unsharp_mask(image_gray, smoothing_param, intensity, clampmax)
+
+Apply unsharp masking on (equalized) grayscale ([0, `clampmax`]) image to enhance its sharpness.
+
+# Arguments
+- `image_gray`: The input grayscale image, typically already equalized.
+- `smoothing_param::Int`: The pixel radius for Gaussian blurring (typically between 1 and 10).
+- `intensity`: The amount of sharpening to apply. Higher values result in more pronounced sharpening.
+- `clampmax`: upper limit of intensity values in the returned image.`
+# Returns
+The sharpened grayscale image with values clipped between 0 and `clapmax`.
+"""
+function unsharp_mask(image_gray, smoothing_param, intensity, clampmax)
+    image_smoothed = imfilter(image_gray, Kernel.gaussian(smoothing_param))
+    clamp!(image_smoothed, 0.0, clampmax)
+    image_sharpened = image_gray * (1 + intensity) .- image_smoothed * intensity
+    clamp!(image_sharpened, 0.0, clampmax)
+    return round.(Int, image_sharpened)
+end
+
+# For old workflow in final2020.m
+"""
+    (Deprecated)
+    unsharp_mask(image_gray, smoothing_param, intensity)
+
+Apply unsharp masking on (equalized) grayscale image to enhance its sharpness.
 
-    image_sharpened =
-        image_equalized_gray .* (1 + intensity) .+ image_smoothed .* (-intensity)
-    return min.(max.(image_sharpened, 0.0), 1.0)
+Does not perform clamping after the smoothing step. Kept for legacy tests of IceFloeTracker.jl.
+
+# Arguments
+- `image_gray`: The input grayscale image, typically already equalized.
+- `smoothing_param::Int`: The pixel radius for Gaussian blurring (typically between 1 and 10).
+- `intensity`: The amount of sharpening to apply. Higher values result in more pronounced sharpening.
+# Returns
+The sharpened grayscale image with values clipped between 0 and `clapmax`.
+"""
+function unsharp_mask(image_gray, smoothing_param, intensity)
+    image_smoothed = imfilter(image_gray, Kernel.gaussian(smoothing_param))
+    image_sharpened = image_gray * (1 + intensity) .- image_smoothed * intensity
+    return clamp.(image_sharpened, 0.0, 1.0)
 end
 
 """