diff --git a/index.md b/index.md
index 79eaa929..f55b15e7 100644
--- a/index.md
+++ b/index.md
@@ -1530,11 +1530,13 @@ Each object in `channels` MAY contain the following fields:
 - `color` (string) String of 6 hexadecimal digits specifying the color of the channel in RGB format.
 - `label` (string) Channel name.
 - `active` (boolean) Indicates whether the channel should be displayed.
-- `window` (dictionary) Values describing the windowing of the channel. All values are optional (MAY).
-  The `min` and `max` values may be used by viewers as the range of channel sliders.
+- `window` (dictionary) Values describing the windowing of the channel.
+  If provided, `start` and `end` values MUST be specified.
   All values can be floating-point numbers, but will likely be integers for integer pixel types.
   - `min` (float) Default setting for lower bound for values of `start` field.
+    MAY be used by viewers as the lower range of channel sliders.
   - `max` (float) Default setting for upper bound for values of `end` field.
+    MAY be used by viewers as the upper range of channel sliders.
   - `start` (float) Start of the rendering window.
   - `end` (float) End of the rendering window.
 - `inverted` (boolean) If true, the rendering of darkest to brightest pixels should be inverted.
diff --git a/schemas/image.schema b/schemas/image.schema
index 0907d253..fcba2982 100644
--- a/schemas/image.schema
+++ b/schemas/image.schema
@@ -137,9 +137,7 @@
                 },
                 "required": [
                   "start",
-                  "min",
-                  "end",
-                  "max"
+                  "end"
                 ]
               },
               "label": {
@@ -153,6 +151,9 @@
               },
               "active": {
                 "type": "boolean"
+              },
+              "inverted": {
+                "type": "boolean"
               }
             }
           }