First public commit.

lenser/intv/palette.py

@@ -0,0 +1,45 @@
+"""Mattel Intellivision STIC 16-colour palette (MAME `intv` values).
+
+Verified against MAME pixel reads (white=7 #FFFCFF, brown/olive=11 #546E00,
+magenta=15 #B51A58).  In Color-Stack mode the per-card FOREGROUND is limited to
+the first 8 colours (3 bits); the BACKGROUND (colour-stack entry) may be any of
+the 16.
+"""
+
+from __future__ import annotations
+
+import numpy as np
+
+from ..palette import srgb_to_lab
+
+STIC = np.array([
+    (0x00, 0x00, 0x00),   # 0  black
+    (0x00, 0x2D, 0xFF),   # 1  blue
+    (0xFF, 0x3D, 0x10),   # 2  red
+    (0xC9, 0xCF, 0xAB),   # 3  tan
+    (0x38, 0x6B, 0x3F),   # 4  dark green
+    (0x00, 0xA7, 0x56),   # 5  green
+    (0xFA, 0xEA, 0x50),   # 6  yellow
+    (0xFF, 0xFC, 0xFF),   # 7  white
+    (0xBD, 0xAC, 0xC8),   # 8  grey
+    (0x24, 0xB8, 0xFF),   # 9  cyan
+    (0xFF, 0xB4, 0x1F),   # 10 orange
+    (0x54, 0x6E, 0x00),   # 11 brown / olive
+    (0xFF, 0x4E, 0x57),   # 12 pink
+    (0xA4, 0x96, 0xFF),   # 13 light blue
+    (0x75, 0xCC, 0x80),   # 14 yellow-green
+    (0xB5, 0x1A, 0x58),   # 15 magenta
+], dtype=np.float64)
+
+# Foreground colours usable per card in Color-Stack mode (3-bit field).
+FG_USABLE = list(range(8))
+# Background (colour-stack) may be any of the 16.
+BG_USABLE = list(range(16))
+
+
+def get_palette() -> np.ndarray:
+    return STIC
+
+
+def palette_lab() -> np.ndarray:
+    return srgb_to_lab(STIC)