Add fix_line_brightness

vsadjust/levels.py

@@ -90,3 +90,54 @@ def fix_double_range(clip: vs.VideoNode) -> vs.VideoNode:
     )
 
     return ColorRange.LIMITED.apply(fix)
+
+
+def fix_line_brightness(
+    clip: vs.VideoNode,
+    rows: Dict[int, float] = {},
+    columns: Dict[int, float] = {},
+) -> vs.VideoNode:
+    """
+    Fix darkened or brightened luma rows or columns using manual level adjustments.
+
+    Adjustments are fix_levels calls where max/min in is moved by adjustment / 100 * peak - low.
+    As such, adjustment values must lie in (-100, 100).
+
+    :param clip: The clip to process.
+    :param rows: Rows and their adjustment values. Rows < 0 are counted from the bottom.
+    :param columns: Columns and their adjustment values. Columns < 0 are counted from the left.
+
+    :return: Clip with adjusted rows and columns.
+    """
+    func = FunctionUtil(clip, fix_line_brightness, 0, vs.GRAY, 32)
+
+    fix = func.work_clip
+    color_range = ColorRange.from_video(fix)
+    peak = get_peak_value(fix, False, color_range)
+    low = get_lowest_value(fix, False, color_range)
+    low_to_peak = peak - low
+
+    def _fix_line(clip: vs.VideoNode, is_row: bool, num: int, adjustment: float) -> vs.VideoNode:
+        if 100 < adjustment < -100:
+            raise ValueError("fix_line_brightness: adjustment values must be in (-100, 100)")
+
+        if adjustment > 0:
+            adj = lambda c: fix_levels(c, max_in=peak - low_to_peak * adjustment / 100, max_out=peak)
+        elif adjustment < 0:
+            adj = lambda c: fix_levels(c, min_in=low + low_to_peak * adjustment / 100, min_out=low)
+        else:
+            return clip
+        if is_row:
+            return rekt_partial(clip, top=num, bottom=clip.height - num - 1, func=adj)
+        return rekt_partial(clip, left=num, right=clip.width - num - 1, func=adj)
+
+    for row, adj in rows.items():
+        if row < 0:
+            row += clip.height
+        fix = _fix_line(fix, True, row, adj)
+    for col, adj in columns.items():
+        if col < 0:
+            col += clip.width
+        fix = _fix_line(fix, False, col, adj)
+
+    return func.return_clip(fix)