code review 6479044: tiff: new Options parameter for Encode.

tiff/writer.go

 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package tiff
 
 import (
         "encoding/binary"
         "image"
         "io"
@@ skipping 135 matching lines @@
         Compression CompressionType
         // Predictor determines whether a differencing predictor is used;
         // if true, instead of each pixel's color, the color difference to the
         // preceding one is saved.  This improves the compression for certain
         // types of images and compressors. For example, it works well for
         // photos with Deflate compression.
         Predictor bool
 }
 
 // Encode writes the image m to w. opt determines the options used for
-// encoding, such as the compression type. If it is nil, an uncompressed
+// encoding, such as the compression type. If opt is nil, an uncompressed
 // image is written.
 func Encode(w io.Writer, m image.Image, opt *Options) error {
         predictor := false
         compression := Uncompressed
         if opt != nil {
                 predictor = opt.Predictor
                 compression = opt.Compression
         }
         if compression != Uncompressed || predictor {
                 return UnsupportedError("compression type")
@@ skipping 41 matching lines @@
                 {tRowsPerStrip, dtShort, []uint32{uint32(height)}},
                 {tStripByteCounts, dtLong, []uint32{uint32(imageLen)}},
                 // There is currently no support for storing the image
                 // resolution, so give a bogus value of 72x72 dpi.
                 {tXResolution, dtRational, []uint32{72, 1}},
                 {tYResolution, dtRational, []uint32{72, 1}},
                 {tResolutionUnit, dtShort, []uint32{resPerInch}},
                 {tExtraSamples, dtShort, []uint32{extrasamples}},
         })
 }