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PureJPEG
Remove Unnecessary Disclosure And Reduce The Size Of
Your Images
Introduction
PureJPEG is an easy to use, high performance utility to remove
unnecessary data from images you email or post on the net, without
affecting the image quality whatsoever (no decompression/recompression
is performed in the filtration), removing such extraneous information
as:
- Digital camera technical data (EXIF)
- Comment blocks
- JPEG thumbnails
- Application blocks
While you should never use this application on your personal image
archive (where this information may actually serve a purpose in some
scenarios), it is generally worthwhile to purify JPEG files when
sharing images, or when posting images online.
Usage
PureJPEG is a command line application, and has three primary
methods of execution.
- purejpeg.exe : When no parameters are provided, files to
process are taken from the console input, separated by linefeeds, until
an EOF (Ctrl-Z) is encountered. Files are overwritten. This is most
commonly used to pipe file lists between applications
- purejpeg.exe [infilename] : When one parameter is
provided, the parameter is used as the input file, and is subsequently
used as the output file -- the original file is overwritten with the
filtered output
- purejpeg.exe [infilename] [outfilename] : When two
parameters are provided, the first parameter is used as the input file,
and the second is used as the output file
Examples
- purejpeg.exe dogs.jpg : Filter extraneous information out
of dogs.jpg in the current directory, overwriting the original only if
no errors occur
- purejpeg.exe dogs.jpg dogs_filtered.jpg : Filter
extraneous information out of dogs.jpg, leaving the original while
writing the new filtered output to dogs_filtered.jpg
- dir /B /S /A-D *.jpg | purejpeg : This is a more complex
piping for more advanced users. The first command (preceding the |) is
a standard directory and subdirectory listing of all jpeg files in the
current directory or any directory below it, with parameters causing
the command to only list filenames without additional output. This
filelist is piped to the pureJPEG application which very rapidly
filters them one by one. If an error is encountered an error message
will be emitted and the process will continue with the next file
FAQ
- What Does This Cost?
- Nothing. This trivial product was created using a very small
amount of code from a revolutionary product that yafla will be
releasing in the new year, and is offered as a public service. This is,
as we've said, a very trivial product.
- What Support Is Provided?
- None. This product is released "as is" , and it is your
responsibility to ensure that you have backups of all images which you
process. While we are extremely confident in the quality of this
product, it doesn't have a business model that justifies us shouldering
any liability.
- What's The Point?
- Many people are unknowingly revealing information when they share
pictures with friends and family, or when they post their pictures on
the web (for instance on a blog or for an auction). This information
includes a wide array of information, including the make and model of
camera used, the exact date and time that the photo was taken, among a
huge array of additional info. In addition some applications used to
edit or view images quietly append identifying information onto your
pictures. While this is often harmless disclosure, it's also completely
unnecessary disclosure - if your readers don't need to know that you
used an expensive new high-end digital camera to shoot your picture,
then why tell them?
- Okay, If I'm Not Paranoid Then What's The Point?
- This additional information can significantly bulk up JPEGs -
some images found on popular websites were found to be over
80% extraneous information. This is information that is of no
value whatsoever to visitors (it does not alter the display of the
image in any way), and it increases the transfer times and increases
the bandwidth demands on the site. The longer a visitor waits for a
bunch of irrelevant JPEG application blocks to transfer the more likely
they click back and follow a different google result.
- Do The Images Look Different After Filtering?
- Not at all. Browsers skip the information that is filtered, as
does Outlook and most other viewers.
- So, Should I Wholesale Filter My Picture Archive?
- Absolutely not! Some photo organization apps use
this information to categorize pictures, and some applications you use
to edit or view pictures use the application blocks for specialization.
Unless you're running really short on hard drive space it's better to
leave the data for personal archival.