[Libexif-devel] libexif for raw images

[Udi F. <udi...@gm...>]

Hi,

I'm the author of UFRaw (http://ufraw.sourceforge.net/), which is a
tool for converting raw images from digital camera, based on DCRaw.

I got a patch for reading the EXIF data from some raw format. It uses
libtiff and libexif and it is base on the fact that some raw file are
actually TIFF files (Nikon NEF, Canon CR2, Pentax PEF).

I merged this code into the development version of UFRaw, which can be
checked-out from the CVS. I have the following issues with this patch:

1. The code looks like a hack to make libexif read the TIFF file.
Isn't there a more natural way for libexif to read TIFF files?

2. I can read the MakerNotes, but if I try "exif --show-mnote" on the
generated JPG file, it seems that it contains no information. The
output is:
MakerNote contains 43 values:
Firmware Version: Firmware Version
ISO Setting: ISO Setting
Quality: Quality
Whitebalance: Whitebalance
...
The problem is in the generated JPG and not in the original raw file,
since using 'ufraw-exif' (see later on) I get these fields correctly.

3. Other raw format are not TIFF files, but have somewhat similar
format. Could there be a "simple" way to generalize this code for
these files?

Could you look at the code, and tell me what you think of it? To
simplify your lives I created also a small stand-alone version. After
the cvs checkout you need to:
./autogen.sh
./configure --enable-extras
make
This will create an extra executable 'ufraw-exif' which is based only
on ufraw_exif.c, so you don't need to look at any of the other ufraw
source files. It's usage is very simple:

usage: ufraw-exif input-file.raw [output-file.jpg]
ufraw-exif dumps the EXIF data from the RAW file to stdout.
If a JPEG file is specified, the EXIF data is copied to it.
This overwrites the original JPEG, so make sure you have a backup for it.

I can also send people some sample RAW files on demand.

Udi