Added porosity to fractal_noise to fix #963

src/porespy/generators/_noise.py

@@ -6,6 +6,7 @@
 
 def fractal_noise(
     shape,
+    porosity: float = None,
     frequency: float = 0.05,
     octaves: int = 4,
     gain: float = 0.5,
@@ -15,13 +16,16 @@ def fractal_noise(
     uniform: bool = True,
 ):
     r"""
-    Generate fractal noise which can be thresholded to create binary
-    images with realistic structures across scales.
+    Generate fractal noise with realistic structures across scales.
 
     Parameters
     ----------
     shape : array_like
         The size of the image to generate, can be 2D or 3D.
+    porosity : float
+        If specified, this will convert the noise distribution to uniform 
+        (no need to set uniform to ``True``), and then threshold the image 
+        to the specified value prior to returning. 
     frequency : scalar, default=0.05
         Controls the overall scale of the generated noise, with larger
         values giving smaller structures.
@@ -98,6 +102,8 @@ def fractal_noise(
     perlin.perturb.perturbType = PerturbType.NoPerturb
     perlin.seed = seed
     result = perlin.genAsGrid(shape)
-    if uniform:
+    if porosity or uniform:
         result = all_to_uniform(result, scale=[0, 1])
+    if porosity:
+        result = result < porosity
     return result