From fb6b8601721da507f590c85a1b9f426f6c45cca6 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Sat, 30 Mar 2024 11:33:55 +1100
Subject: [PATCH] Added RGB to I;16, I;16L and I;16B conversion

---
 Tests/helper.py          |  2 --
 src/libImaging/Convert.c | 23 +++++++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/Tests/helper.py b/Tests/helper.py
index 9849bf65565..bdd195bf048 100644
--- a/Tests/helper.py
+++ b/Tests/helper.py
@@ -263,8 +263,6 @@ def hopper(mode: str | None = None, cache: dict[str, Image.Image] = {}) -> Image
     if im is None:
         if mode == "F":
             im = hopper("L").convert(mode)
-        elif mode[:4] == "I;16":
-            im = hopper("I").convert(mode)
         else:
             im = hopper().convert(mode)
         cache[mode] = im
diff --git a/src/libImaging/Convert.c b/src/libImaging/Convert.c
index 0b84aa1ba73..75fdab820e5 100644
--- a/src/libImaging/Convert.c
+++ b/src/libImaging/Convert.c
@@ -250,6 +250,26 @@ rgb2i(UINT8 *out_, const UINT8 *in, int xsize) {
     }
 }
 
+static void
+rgb2i16l(UINT8 *out_, const UINT8 *in, int xsize) {
+    int x;
+    for (x = 0; x < xsize; x++, in += 4) {
+        UINT8 v = CLIP16(L24(in) >> 16);
+        *out_++ = v;
+        *out_++ = v >> 8;
+    }
+}
+
+static void
+rgb2i16b(UINT8 *out_, const UINT8 *in, int xsize) {
+    int x;
+    for (x = 0; x < xsize; x++, in += 4) {
+        UINT8 v = CLIP16(L24(in) >> 16);
+        *out_++ = v >> 8;
+        *out_++ = v;
+    }
+}
+
 static void
 rgb2f(UINT8 *out_, const UINT8 *in, int xsize) {
     int x;
@@ -944,6 +964,9 @@ static struct {
     {"RGB", "LA", rgb2la},
     {"RGB", "La", rgb2la},
     {"RGB", "I", rgb2i},
+    {"RGB", "I;16", rgb2i16l},
+    {"RGB", "I;16L", rgb2i16l},
+    {"RGB", "I;16B", rgb2i16b},
     {"RGB", "F", rgb2f},
     {"RGB", "BGR;15", rgb2bgr15},
     {"RGB", "BGR;16", rgb2bgr16},