| Subject: | incorrect "FocalPlaneResolutionUnit" |
It seems as if in TIFF.pm the decoding of FocalPlaneResolutionUnit is done incorrectly. FocalPlaneResolutionUnit is not defined in the TIFF 6.0 documentation. However, it IS defined in the Exif docs (2.1 and 2.2). Since TIFF.pm is used for Exif decoding, it should follow the Exif documentation.
The Exif Documentation specifies that FocalPlaneResolutionUnit is to be interpreted the same as ResolutionUnit (which is decoded properly). Apparently, the author of TIFF.pm was a little bit confused himself, judging from the comments in the FocalPlaneResolutionUnit section 8-). I hope this clears up the confusion and results in a fixed TIFF.pm.
I have also included a patch.
Martin
PS:
Although I am using 1.09 (Debian is out of date?!), this same bug is present in 1.16. (patch is against 1.16)
perl -v:
This is perl, v5.8.3 built for i386-linux-thread-multi
<snip>
uname -a:
Linux martin1 2.4.25 #1 Wed Mar 10 15:55:57 EST 2004 i686 GNU/Linux
(Debian unstable)
--- Image/TIFF.pm 2004-01-07 06:44:00.000000000 -0500
+++ ImageNew/TIFF.pm 2004-04-14 22:20:39.000000000 -0400
@@ -464,13 +464,11 @@
0xA20C => "SpatialFrequencyResponse", # 0x920C - -
0xA20E => "FocalPlaneXResolution", # 0x920E - -
0xA20F => "FocalPlaneYResolution", # 0x920F - -
+
0xA210 => { __TAG__ => "FocalPlaneResolutionUnit", # 0x9210 - -
- 1 => "dpi", # 25.4
- 2 => "dpm", # 25.4??
- 3 => "dpcm", # 10
- 4 => "dpmm", # 1
- 5 => "dpµm", # .001
- },
+ 1 => "pixels", 2 => "dpi", 3 => "dpcm",
+ },
+
0xA214 => "SubjectLocation", # 0x9214 - -
0xA215 => "ExposureIndex", # 0x9215 - -
0xA217 => {__TAG__ => "SensingMethod",