Fix bits value for RGB;16N unpackers

Tests/test_file_libtiff.py

@@ -631,6 +631,21 @@ class TestFileLibTiff(LibTiffTestCase):
         # Should not raise UnicodeDecodeError or anything else
         im.save(outfile)
 
+    def test_16bit_RGB_tiff(self):
+        im = Image.open("Tests/images/tiff_16bit_RGB.tiff")
+
+        self.assertEqual(im.mode, "RGB")
+        self.assertEqual(im.size, (100, 40))
+        self.assertEqual(
+            im.tile,
+            [('tiff_adobe_deflate', (0, 0, 100, 40), 0,
+              ('RGB;16N', 'tiff_adobe_deflate', False))]
+        )
+        im.load()
+
+        self.assert_image_equal_tofile(
+            im, "Tests/images/tiff_16bit_RGB_target.png")
+
     def test_16bit_RGBa_tiff(self):
         im = Image.open("Tests/images/tiff_16bit_RGBa.tiff")
 

src/libImaging/Unpack.c

@@ -1369,12 +1369,12 @@ static struct {
     {"RGBA",    "A",            8,      band3},
 
 #ifdef WORDS_BIGENDIAN
-    {"RGB",     "RGB;16N",      64,     unpackRGB16B},
+    {"RGB",     "RGB;16N",      48,     unpackRGB16B},
     {"RGBA",    "RGBa;16N",     64,     unpackRGBa16B},
     {"RGBA",    "RGBA;16N",     64,     unpackRGBA16B},
     {"RGBX",    "RGBX;16N",     64,     unpackRGBA16B},
 #else
-    {"RGB",     "RGB;16N",      64,     unpackRGB16L},
+    {"RGB",     "RGB;16N",      48,     unpackRGB16L},
     {"RGBA",    "RGBa;16N",     64,     unpackRGBa16L},
     {"RGBA",    "RGBA;16N",     64,     unpackRGBA16L},
     {"RGBX",    "RGBX;16N",     64,     unpackRGBA16B},