DoG

workshops/image-feature-enhancement.md

+# Image feature enhancement
+
+<img src='https://g.gravizo.com/svg?
+ digraph G {
+    shift [fontcolor=white,color=white];
+    image -> filter -> "enhanced image";
+    "enhanced image" -> "feature" [label="  aka"];
+    filter -> "feature enhancement" [label=" aka"];   
+}
+'/>
+
+
+
+## Difference of Gaussian (DoG) for spot enhancement
+
+<img src='https://g.gravizo.com/svg?
+ digraph G {
+	shift [fontcolor=white,color=white];
+	image -> "small blur";
+	image -> "large blur";
+	"small blur" -> "remove noise";
+	"large blur" -> "estimate local background";
+	"small blur" -> "DoG = small blur - large blur";
+	"large blur" -> "DoG = small blur - large blur";
+}
+'/>
+
+### Activity: Enhance spots in noisy image with uneven background
+
+- Open image: xy_8bit__two_spots_noisy_uneven_background.tif
+- Appreciate that you cannot simply threshold them
+- Copy the image and blur with a Gaussian of small radius -> gs
+- Copy the image and blur with a Gaussian of bigger radius -> gb
+- Create `DoG = gs - gb`
+- Appreciate that you can simply threshold the DoG image
+ 
+### Formative Assessment
+
+TODO
+
+### Learn more
+
+- https://en.wikipedia.org/wiki/Difference_of_Gaussians
+

workshops/machine-learning-semantic-image-segmentation.md

@@ -13,7 +13,7 @@
     "pixel class image" -> "class00 value";
     "pixel class image" -> "class01 value";
     "pixel class image" -> "class.. value";
-    "pixel class image" -> "class N value";
+    "pixel class image" -> "class C value";
  }
 '/>
 

workshops/rank-filters.md

+# Rank filters
+