add entropy measure

jcupitt · jcupitt · commit df954a059a6e · 2017-03-20T14:01:14.000Z
diff --git a/ChangeLog b/ChangeLog
@@ -5,6 +5,7 @@ started 8.5 24/1/17
 - parse_float was broken for numbers starting "0."
 - add alpha section to Image / Band menu ... Flatten, Premultiply,
   Unpremultiply, Blend
+- add Entropy to hist menu
 
 started 8.4.1 25/9/16
 - simplify nip2-icon.rc build, bgilbert
diff --git a/TODO b/TODO
@@ -2,8 +2,6 @@
 
     (split is_space x)?0
 
-- add entropy menu item
-
 - how about adding
 
 	zip2 10 [1..5] == [[10, 1], [10, 2], [10, 3], ..
diff --git a/share/nip2/start/Histogram.def b/share/nip2/start/Histogram.def
@@ -162,6 +162,10 @@ Hist_zerox_item = class
 	}
 }
 
+Hist_entropy_item = class Menuaction "Entropy" "calculate histogram entropy" {
+	action x = hist_entropy x;
+}
+
 #separator
 
 Hist_profile_item = class 
diff --git a/share/nip2/start/_stdenv.def b/share/nip2/start/_stdenv.def
@@ -2578,3 +2578,20 @@ unpremultiply x
 	}
 }
 
+hist_entropy x 
+	= oo_unary_function hist_entropy_op x, is_class x
+	= entropy x, is_image x 
+	= error (_ "bad arguments to " ++ "hist_entropy")
+{
+	hist_entropy_op = Operator "hist_entropy" 
+		hist_entropy Operator_type.COMPOUND_REWRAP false;
+
+	entropy x
+		= out
+	{
+		[out] = vips_call "hist_entropy" [x] [
+		];
+	}
+}
+
+

Original file line number	Diff line number	Diff line change
`@@ -162,6 +162,10 @@ Hist_zerox_item = class`
`162`	`162`	`}`
`163`	`163`	`}`
`164`	`164`
	`165`	`+Hist_entropy_item = class Menuaction "Entropy" "calculate histogram entropy" {`
	`166`	`+ action x = hist_entropy x;`
	`167`	`+}`
	`168`	`+`
`165`	`169`	`#separator`
`166`	`170`
`167`	`171`	`Hist_profile_item = class`