Previous: (Page 1) JPEG Metadata Privacy Alert Introduction
Question: How did you discover metadata was affecting the digital photographs you were working with?
Ian Fieggen: I use a variety of image editing software and found that certain programs seemed to consistently produce larger files for the same perceived quality. Being a natural born dabbler, I inspected the innards of the files and found that they contained a whole bunch of readable text. I concluded that there was probably just as much non-readable binary data.
Question: How did you end up developing JPGExtra?
Ian Fieggen: I've been a programmer for decades, so it was a simple matter to create a quick and dirty program to re-write JPG files minus anything that I couldn't identify and that seemed to be "extras". However, to create a reliable program in which I could be 100% confident, I needed more information about which parts of the JPG file were needed and which could be discarded.
The theoretical information about the JPG format came from a number of technical sources. But the real, practical information about what was actually in JPG files came from manually examining the contents of thousands of files, both those available on the Internet at present and those that I
dug out of old computers, old software installation disks, etc. These were used to fine tune the program for various "unusual" configurations. Over 50,000 JPG files were successfully tested and optimized with JPGExtra before I felt totally confident.
Question: Wedding couples and professional photojournalists tend to be on a tight budget. JPGExtra offers fantastic flexibility in licensing, how does it work?
Ian Fieggen: I'm not a huge software corporation, just an individual who's written a program that others may find useful. The free trial version will fully optimize up to ten images per session. For many individuals, the free trial version is more than enough for day to day usage. The fully paid version can optimize thousands of images in one pass, or even a whole drive full. This version can be purchased for whatever you feel is a "fair price", which can be anything from $1 upwards. It's a bit like leaving a tip in a restaurant, or throwing a coin into the hat of a street performer or busker.
Question: What are some of the worst culprits in adding metadata to photographs?
Ian Fieggen: Most modern digital cameras are starting to add increasingly large amounts of metadata. In particular, small and/or medium resolution versions of the image (typically called "thumbnails"). Probably the biggest culprit is the image editing software, PhotoShop, which keeps anything added by the camera as well as adding its own thumbnail(s), colour profiles, plus various other data. JPG files that have been edited by PhotoShop can typically contain 30,000 to 50,000 bytes of "extras".
Question: What are some of the file size advantages when using JPGExtra?
Ian Fieggen: The largest saving in file size that I've ever had with JPG files was 312,296 bytes, which consisted of a JPG file that contained two almost exact copies of the same image. The vast majority of files that have had substantial improvements have seen savings of around 30,000 to 40,000 bytes, consisting of digital camera data, two or three thumbnail images, comments, PhotoShop data, XML and XAP data, plus ICC color profile data.
If the source image is large (2 to 3 Mb), this saving only represents a tiny percentage (around 2%). However, when images are about the size that is used on web sites or e-mails, this saving can easily amount to a much higher percentage of around 30 to 50%. It's no use wasting extra upload and download time to e-mail photos containing these hidden extras!
Question: What are some of the security issues with metadata?
Ian Fieggen: The biggest issue is whether the metadata contains "private" information. For example, a photo may have been edited to remove some detail or to obscure someone's identity (such as blurring a face). However, it's possible for the metadata to contain a copy of the original, un-edited image. Someone savvy with inspecting the inner contents of file would be able to extract that image.
If you don't want others to see anything that you've edited out of the image, or to know the make and model of your camera, the exact date and time a photo was taken, the serial number of the software used to edit the image, or any number of other snippets of information, it's important to remove this metadata.
Question: For the average consumer, are there any benefits to metadata in general?
Ian Fieggen: Metadata may be important for your own purposes. For example, if you transfer an image back onto your digital camera, you may be unable to see a preview of that image on the camera unless the digital camera's metadata is kept intact. Some software will also use the embedded thumbnail images as a quick preview, so stripping them may slow down the display of such previews.
Note that I don't necessarily recommend that all images be permanently stripped of their metadata. I generally keep my original images intact and only optimize copies of images that are to be used or distributed elsewhere, such as on web sites.
Question: As digital photography becomes more and more popular, are there any changes or trends in image formats that might become popular as a result?
Ian Fieggen: I'm not really an expert in this field, but I think that we may see more use of JPEG2000 and PNG image formats, both of which use lossless compression (meaning that there will be absolutely no loss of image quality). Whilst these both use much more disk space than the regular lossy JPG format, professionals may start to use them in preference to other traditional formats like TIF.
Question: Metadata is becoming a growing issue with the popularity of image sharing websites. How do you see metadata evolving in this area?
Ian Fieggen: Where my program is designed to simply strip out ALL metadata, perhaps we will start to see more programs that allow viewing metadata and either a more selective removal or editing of individual bits of metadata.
Question: JPGExtra is a fantastic program at removing metadata from JPEGs. Any thoughts on including other image formats?
Ian Fieggen: It would be great for my program to offer a one-stop solution. I've looked into other popular formats of image files, such as GIF and PNG, but from what I've seen (superficially at least), they don't appear to have the same problem with excess metadata. For the moment, at least.
Question: What does the future hold for JPGExtra? Are there any new features you're interested in implementing?
Ian Fieggen: The next feature I'd like to implement is the selective removal of metadata, such as being able to tick which bits to keep and which to discard. It would also be nice to include an image viewer, although I'm conscious of not straying too far from my initial aim to have a tiny, functional utility.
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