Add new scale_mask & scale_delta helpers (#161)

vstools/utils/scale.py

@@ -10,7 +10,7 @@
 from .info import get_depth, get_video_format
 
 __all__ = [
-    'scale_value',
+    'scale_value', 'scale_mask', 'scale_delta',
 
     'get_lowest_value', 'get_neutral_value', 'get_peak_value',
     'get_lowest_values', 'get_neutral_values', 'get_peak_values',
@@ -97,6 +97,59 @@ def scale_value(
     return out_value
 
 
+def scale_mask(
+    value: int | float,
+    input_depth: int | VideoFormatT | HoldsVideoFormatT,
+    output_depth: int | VideoFormatT | HoldsVideoFormatT
+) -> int | float:
+    """
+    Converts the value to the specified bit depth, or bit depth of the clip/format specified.
+    Intended for mask clips which are always full range.
+
+    :param value:           Value to scale.
+    :param input_depth:     Input bit depth, or clip, frame, format from where to get it.
+    :param output_depth:    Output bit depth, or clip, frame, format from where to get it.
+
+    :return:                Scaled value.
+    """
+
+    return scale_value(value, input_depth, output_depth, ColorRange.FULL, ColorRange.FULL)
+
+
+def scale_delta(
+    value: int | float,
+    input_depth: int | VideoFormatT | HoldsVideoFormatT,
+    output_depth: int | VideoFormatT | HoldsVideoFormatT,
+    range_in: ColorRangeT | None = None,
+    range_out: ColorRangeT | None = None,
+) -> int | float:
+    """
+    Converts the value to the specified bit depth, or bit depth of the clip/format specified.
+    Uses the clip's range (if only one clip is passed) for both depths.
+    Intended for filter thresholds.
+
+    :param value:           Value to scale.
+    :param input_depth:     Input bit depth, or clip, frame, format from where to get it.
+    :param output_depth:    Output bit depth, or clip, frame, format from where to get it.
+    :param range_in:        Color range of the input value
+    :param range_out:       Color range of the desired output.
+
+    :return:                Scaled value.
+    """
+
+    if isinstance(input_depth, vs.VideoNode) != isinstance(output_depth, vs.VideoNode):
+        if isinstance(input_depth, vs.VideoNode):
+            clip_range = input_depth
+        if isinstance(output_depth, vs.VideoNode):
+            clip_range = output_depth
+
+        clip_range = ColorRange.from_video(clip_range)
+        range_in = clip_range if range_in is None else range_in
+        range_out = clip_range if range_out is None else range_out
+
+    return scale_value(value, input_depth, output_depth, range_in, range_out, False)
+
+
 def get_lowest_value(
     clip_or_depth: int | VideoFormatT | HoldsVideoFormatT, chroma: bool = False,
     range_in: ColorRangeT | None = None, family: vs.ColorFamily | None = None