The two dims stopped stacking, and centre court's crowd is graded off a lifted target

Oliver: "it is too dim to see anything on the centre court and the dark court."
Both were the same mistake — standBack was ADDED to a court's own dim instead of
being the default it falls back to. Centre court's crowd sheet is a night-lit
navy that is dark to begin with, and the night court dims the hard-court sheet
on top of that, so the pair of them went to mud.

standDim is now court.dim ?? TUNE.standBack, plus the rot. Centre court carries
a 0.06 of its own, the night court comes down 0.62 -> 0.5 (it no longer has the
base added to it), and clay and hard keep the 0.22 that was approved.

Centre court's sheet is also graded off a LIFTED target now — the old crowd it
matches sat at a mean luminance of 39 against clay's 96, dark enough to throw
the new roll's detail away before any dim ran. A 0.72 gamma on the target brings
the sheet to 60 and the faces come back.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

assets/_crowdpass.py

@@ -55,7 +55,12 @@ PAL = 128              # colours a sheet is quantised to on save
 # HEAD, so re-running the tool after installing its own output cannot drift the palettes.
 GRADE_REF = '76ea1d0'
 
-COURTS = [('x_crowd', 'x_crowd2'), ('x_crowd_c', 'x_crowd_c2'), ('x_crowd_h', 'x_crowd_h2')]
+# sheet -> how much its grade TARGET is lifted before the histogram match (a gamma; 1.0 is the old
+# sheet as it was). Centre court's old crowd sat at a mean luminance of 39 against clay's 96 — dark
+# enough that the detail in the new roll was being thrown away, and then dimmed on top of that:
+# Oliver, "it is too dim to see anything on the centre court and the dark court". The night court
+# borrows the hard-court sheet and does its own dimming in `COURTS.dim`, so it is fixed there.
+COURTS = [('x_crowd', 0.72), ('x_crowd_c', 1.0), ('x_crowd_h', 1.0)]
 
 MIN_AREA, MAX_AREA = 150, 3000   # an arm blob: one pair of raised arms, or one arm
 ARM_H, ARM_W = (10, 70), (8, 90)  # ...and its shape, in px of the 1408x768 sheet
@@ -199,8 +204,11 @@ def main(review):
     print(f'{len(rows)} spectators can move, {both} of them with both poses (a real clap)')
 
     stack = np.concatenate(frames, 0)
-    for a_name, _ in COURTS:
-        lut = grade(A, old_sheet(a_name))              # the LOOK is judged on the seated frame...
+    for a_name, lift in COURTS:
+        ref = old_sheet(a_name)
+        if lift != 1.0:
+            ref = (255 * (ref / 255.0) ** lift).astype(np.uint8)
+        lut = grade(A, ref)                            # the LOOK is judged on the seated frame...
         pa = os.path.join(REFCHECK if review else HERE, a_name + ('_new.png' if review else '.png'))
         # ...and applied to the whole stack at once, so the frames cannot drift apart in colour
         Image.fromarray(lut(stack)).quantize(colors=PAL, method=Image.MEDIANCUT).save(pa, optimize=True)