Read 16-bit images into I;16B mode to allow for memory mapping

Author: radarhere

Tests/images/cmx3g8_wv_1998.260_0745_mcidas.tiff

@@ -27,6 +27,6 @@ def test_valid_file() -> None:
 
         # Assert
         assert im.format == "MCIDAS"
-        assert im.mode == "I"
+        assert im.mode == "I;16B"
         assert im.size == (1800, 400)
         assert_image_equal_tofile(im, saved_file)

Tests/test_file_mcidas.py

@@ -50,9 +50,7 @@ def _open(self) -> None:
         if w[11] == 1:
             mode = rawmode = "L"
         elif w[11] == 2:
-            # FIXME: add memory map support
-            mode = "I"
-            rawmode = "I;16B"
+            mode = rawmode = "I;16B"
         elif w[11] == 4:
             # FIXME: add memory map support
             mode = "I"