light de-banding when they exceed 255 out of 1023

work_files/HDRcurveBezierLinIntp.kts

@@ -0,0 +1,28 @@
+/**
+ * Weighted bezier curve interpolation by making bunch of linear curves, calculating intersect points between
+ *     y = 1 / (1 + 3 * (k / n)) * eks ; eks <- [0..1023]
+ *     (where k: step, n: max step)
+ * and take smallest value
+ */
+
+val ymax = 260.0 // NOT a mistake!
+val n = 1024
+val polynomial = 6.0
+val curves = Array(n, { k -> { eks: Int ->
+    val p = k.toDouble() / n.toDouble()
+    val m = (ymax - ymax * p) / (768.0 * Math.pow(p, polynomial) + 256.0 - ymax * p)
+    m * (eks - ymax * p) + ymax * p
+} })
+
+
+print("\n\n")
+
+(0..n - 1).forEach { step ->
+    val intersects = curves.map { f -> f(step) }.sorted()
+    var c = minOf(1f, intersects[0].toFloat() / 256f)
+    if (c < 0f) c = 0f
+    //println("step $step\t$c")
+
+    if (step > 0 && step % 16 == 0) println()
+    print("${c}f,")
+}