Fix #75, #76

Author: hhrutter

ccitt/reader.go

@@ -576,8 +576,13 @@ func (d *decoder) decodeGroup4() {
 
 		mode, err := d.nextMode()
 		if err != nil {
-			d.err = err
-			return
+			// Check for aligned 3 bytes eofb.
+			d.align = true
+			mode, err = d.nextMode()
+			if err != nil {
+				d.err = err
+				return
+			}
 		}
 
 		for k, v := range map[string]func(){

tiff/reader.go

@@ -463,7 +463,8 @@ func newDecoder(r io.Reader) (*decoder, error) {
 	d.config.Height = int(d.firstVal(tImageLength))
 
 	if _, ok := d.features[tBitsPerSample]; !ok {
-		return nil, FormatError("BitsPerSample tag missing")
+		// Default is 1 per specification.
+		d.features[tBitsPerSample] = []uint{1}
 	}
 	d.bpp = d.firstVal(tBitsPerSample)
 	switch d.bpp {