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-rw-r--r--vendor/golang.org/x/image/tiff/compress.go58
1 files changed, 58 insertions, 0 deletions
diff --git a/vendor/golang.org/x/image/tiff/compress.go b/vendor/golang.org/x/image/tiff/compress.go
new file mode 100644
index 0000000..3f176f0
--- /dev/null
+++ b/vendor/golang.org/x/image/tiff/compress.go
@@ -0,0 +1,58 @@
+// Copyright 2011 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 (
+ "bufio"
+ "io"
+)
+
+type byteReader interface {
+ io.Reader
+ io.ByteReader
+}
+
+// unpackBits decodes the PackBits-compressed data in src and returns the
+// uncompressed data.
+//
+// The PackBits compression format is described in section 9 (p. 42)
+// of the TIFF spec.
+func unpackBits(r io.Reader) ([]byte, error) {
+ buf := make([]byte, 128)
+ dst := make([]byte, 0, 1024)
+ br, ok := r.(byteReader)
+ if !ok {
+ br = bufio.NewReader(r)
+ }
+
+ for {
+ b, err := br.ReadByte()
+ if err != nil {
+ if err == io.EOF {
+ return dst, nil
+ }
+ return nil, err
+ }
+ code := int(int8(b))
+ switch {
+ case code >= 0:
+ n, err := io.ReadFull(br, buf[:code+1])
+ if err != nil {
+ return nil, err
+ }
+ dst = append(dst, buf[:n]...)
+ case code == -128:
+ // No-op.
+ default:
+ if b, err = br.ReadByte(); err != nil {
+ return nil, err
+ }
+ for j := 0; j < 1-code; j++ {
+ buf[j] = b
+ }
+ dst = append(dst, buf[:1-code]...)
+ }
+ }
+}