Rewrite dict creation as dict literal for better performance

src/PIL/BmpImagePlugin.py

@@ -76,10 +76,8 @@ class BmpImageFile(ImageFile.ImageFile):
         read, seek = self.fp.read, self.fp.seek
         if header:
             seek(header)
-        file_info = {}
         # read bmp header size @offset 14 (this is part of the header size)
-        file_info["header_size"] = i32(read(4))
-        file_info["direction"] = -1
+        file_info = {"header_size": i32(read(4)), "direction": -1}
 
         # -------------------- If requested, read header at a specific position
         # read the rest of the bmp header, without its size

src/PIL/Image.py

@@ -2992,12 +2992,11 @@ _fromarray_typemap = {
     ((1, 1, 2), "|u1"): ("LA", "LA"),
     ((1, 1, 3), "|u1"): ("RGB", "RGB"),
     ((1, 1, 4), "|u1"): ("RGBA", "RGBA"),
+    # shortcuts:
+    ((1, 1), _ENDIAN + "i4"): ("I", "I"),
+    ((1, 1), _ENDIAN + "f4"): ("F", "F"),
 }
 
-# shortcuts
-_fromarray_typemap[((1, 1), _ENDIAN + "i4")] = ("I", "I")
-_fromarray_typemap[((1, 1), _ENDIAN + "f4")] = ("F", "F")
-
 
 def _decompression_bomb_check(size):
     if MAX_IMAGE_PIXELS is None:

src/PIL/TiffImagePlugin.py

@@ -1748,9 +1748,8 @@ def _save(im, fp, filename):
             SUBIFD,
         ]
 
-        atts = {}
         # bits per sample is a single short in the tiff directory, not a list.
-        atts[BITSPERSAMPLE] = bits[0]
+        atts = {BITSPERSAMPLE: bits[0]}
         # Merge the ones that we have with (optional) more bits from
         # the original file, e.g x,y resolution so that we can
         # save(load('')) == original file.