More Windows corruption woes

Yet again I get a question from a user with images that have been corrupted by editing metadata with Windows. The biggest problem is that Windows may change the byte order of the EXIF when the metadata was edited. This is a REALLY, REALLY BAD thing to do because it is impossible to properly change the byte order of some proprietary information. So the effect is that this information is corrupted, causing errors when other software that parses this information reads the image.

This was a problem with Windows XP up to and including Service Pack 3, but from one report this seems to have been fixed in Vista and Windows 7. If so, there must still be a lot of people running XP out there because I keep seeing this complaint.

First confirmed XMP in original images

I think I now have enough samples to conclude that Canon is embedding XMP into images directly from the camera. Currently the XMP contains only a single tag, "Rating", which has a value of 0 in all my samples. While I thought there was a chance that all of my samples had been modified by some Canon software utility which added the XMP, I have now obtained enough samples from different sources that I believe this is not the case. The samples I have with XMP are from the following PowerShot models: A3100IS, SD980IS, SD1400IS, SD3500IS and SX210IS.

This is significant because in the past the limitations of EXIF have forced camera manufacturers to store information in a proprietary format in images, limiting its usefulness. But now that manufacturers are embracing XMP there is a chance that some of this information could be put in a more useful format.

For instance, it would be GREAT if cameras like the Panasonic DMC-ZS7 stored its location information (Country, City, State, etc) in XMP. Currently this information is stored in the maker notes, which means it is unavailable to most software. (The only reasonable option with the maker note solution is to use ExifTool to copy the information to XMP, which is one of the very useful functions of ExifTool, but in an ideal world this would not be necessary.)

More web server stats

I spent some more time watching the ExifTool web server to see what was getting the most traffic. The most popular file is the "ExifTool Updates" RSS feed, which gets an average of about 2.3 hits per minute -- that's 100,000 hits per month (from more than 20,000 unique IP's). Due to the nature of RSS, I was worried about this file dominating our bandwidth, so I tried to keep it small (12 kB) and set its reload period to 90 minutes (for RSS readers that honour the TTL attribute). Good thing I did that.

ExifTool download statistics

I just checked the web server to see how many people are downloading exiftool. I am now getting more than 1000 downloads per day from the main server. This doesn't include all of the downloads from the various CPAN mirrors and other download sources (which all together could easily be another 1000 per day).

At this rate I could retire with a $40,000 per year salary if I just charged $0.05 per download.

But ExifTool is free.

Stupid Samsung SRW

Samsung has invented another TIFF-based RAW format called SRW (used by the NX10).

The idiot Samsung engineers haven't included any sort of file identifier to allow this type of file to be distinguised from a TIFF image. This means that software must rely on the file extension to be able to read or write this file properly. This really pisses me off. Will they never learn?!

Also, they have included no identifier in their maker notes, which again is not a good idea.

The best one can do to identify these images is to look for a SubIFD1 Compression value of 32770, but this can only be found after processing IFD0 and the SubIFD's.

It would be much better if the file included a signature after the TIFF header such the Canon CR2, or a different TIFF magic number like Olympus ORF.

[Edit - discovered more idiocy]

Another BLACK MARK against the Samsung engineers:

The SRW format stores the ThumbnailImage inside a SubIFD of IFD1 instead of directly in IFD1 as per the EXIF specification.

Why are they so stupid?

Production Leica S2

Well, support for the insane Leica S2 maker notes was finally added in the version of ExifTool that was released a few days ago. Adding this support was as painful as I had anticipated. As it turns out, images from the production model have all the same problems of the pre-production samples. The question about the funny 0x800 offset is explained by the fact that a different offset base is used for one maker note entry (coupled with lots of unnecessary padding to keep the value at a constant offset). Anyone who understands the TIFF IFD structure will realize how stupid this is -- one may draw their own conclusions about the level of understanding by Leica engineers.