all: fix typos

Change-Id: I8f9f58babea80bbdad52df2b67a083f3a381c217
GitHub-Last-Rev: 79ce945721ada79d7a329cec4234d3b7ce977a83
GitHub-Pull-Request: golang/image#8
Reviewed-on: https://go-review.googlesource.com/c/image/+/389054
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Tobias Klauser <tobias.klauser@gmail.com>
diff --git a/font/sfnt/gpos.go b/font/sfnt/gpos.go
index e0aafa5..5f4b765 100644
--- a/font/sfnt/gpos.go
+++ b/font/sfnt/gpos.go
@@ -437,7 +437,7 @@
 		//	 pairs: 130=0, 131=1, 132=2, 133=3, 134=4, 135=5, 137=6
 		//   ranges: 130, 135, 0    137, 137, 6
 		// startCoverageIndex is used to calculate the index without counting
-		// the length of the preceeding ranges
+		// the length of the preceding ranges
 
 		idx := sort.Search(num, func(i int) bool {
 			return gi <= GlyphIndex(u16(ranges[i*6:]))
diff --git a/font/sfnt/sfnt_test.go b/font/sfnt/sfnt_test.go
index a8efa49..ec22060 100644
--- a/font/sfnt/sfnt_test.go
+++ b/font/sfnt/sfnt_test.go
@@ -567,7 +567,7 @@
 	// drawn in a consistent direction. Clockwise for external paths,
 	// anti-clockwise for internal paths. (Actually PostScript requires the
 	// exact opposite, but FontForge reverses PostScript contours when it loads
-	// them so that everything is consistant internally -- and reverses them
+	// them so that everything is consistent internally -- and reverses them
 	// again when it saves them, of course)."
 	//
 	// The .notdef glyph isn't explicitly in the SFD file, but for some unknown
diff --git a/tiff/lzw/reader.go b/tiff/lzw/reader.go
index 78204ba..1930357 100644
--- a/tiff/lzw/reader.go
+++ b/tiff/lzw/reader.go
@@ -30,7 +30,7 @@
 
 The Go code doesn't read (invalid) TIFF files written by old versions of
 libtiff, but the LZW algorithm in this package still differs from the one in
-Go's standard package library to accomodate this "off by one" in valid TIFFs.
+Go's standard package library to accommodate this "off by one" in valid TIFFs.
 */
 
 import (