Hey,
With the ever growing trend of digital cameras and the ability to
take many shots a once, particularly if you have an DSLR, you may find
you have a lot of duplicate photos. Although disk space isn’t a premium
as it once was, having many duplicate files of the same image really is
pointless. Today’s app is called
PhotoSweeper
and it is designed to search through your iPhoto, Aperture or simply
the images you add to the app, and see which are duplicates. It does
this based on how the image looks so it can be pretty good.
Find Those Images
When you start the app, you are given a blank screen. The first step
is to add the images you want to compare. This can either be from
iPhoto, Aperture, Lightroom or by dragging and dropping images onto the
workspace.

Drag your images into the app, adjust the settings and away you go.
The next step is to set up the criteria to compare the images. The
method to find the comparison is to create a thumbnail of the image and
then compare the thumbnails. This allows the app to run quickly; since
it doesn’t have a massive image, pixel by pixel, to compare and the
ability to automatically weed out anomalies and errors within the image.
This allows the app to get a match spot on over the whole image. If the
app compared each pixel of a full size image, any subtle change would
be reported, it would also take for ever to go through your library.
There is a good manual included with the app which gives you a bit more
detail.
The settings allow you to compare the bitmap, which is the pixels within the image. The
histogram,
which compares the amount of colour within each image or the time
interval, so you remove shots that were taken too close together. You
can also combine the time interval with the bitmap or histogram method,
this allows you to pick up images that are taken close together and then
compare them by the image. If you want an exact duplicate option,
rather than a ‘fuzzy’ match, there is that option too. Each one is
explained, with plenty of settings, within the side bar.
When you have picked your option, you hit the compare button and the
app does it’s thing. It managed to use all 8 cores on my mac, at 800%,
and blasted through my iPhoto library in a matter of seconds.
Review Those Images
When the app has reviewed all of the images, you can now begin to
sort and remove the duplicates. The review section has the ability to
adjust the match settings on the fly, so if you want more or less
images, you can quickly change this setting without having to re-compare
your entire selection.

Two images which look very similar, one can be deleted.
You can then move through your library one by one, looking at the
images and seeing which ones can be deleted. The app gives you a
comparison metric, in terms of percent, showing you how close it thinks
each image matches. In the screenshot above, it thinks the image match
92.1%, enough to satisfy a duplicate copy.
When you have gone through the images, you move them to the ‘box’ by
dragging them into the drop zone. It took me a while to work out what
the ‘box’ meant, but it is a final holding pen before the images are
removed.
If you really can’t be bothered to go through each image, one by one,
you can use the ‘auto put’ option which will select the duplicates for
you and put them in the ‘box’.
Delete Those Images
The final step is to delete, move or copy the duplicate images. You
can either delete them, move them to a separate location, or copy them
away. There are option for the move and copy, to rename or append the
file name. Deletion is the last step.
Conclusion
Overall I think this app is pretty good. It finds duplicates well and
has a lot of power under the hood. A lot of time has been spent getting
the core of this app to work. The settings and the work flow through
the app are simple and make it easy to understand.
There are two problems I find with this app, that would otherwise
make it a complete application. Nowhere obvious does it tell you what it
means by ‘box’. It makes sense what it means when you use the app, but
it takes a bit of guessing. I would like to see some clearer, more
obvious instruction as to what it means, or re-name it. The manual in
this regard references the ‘box’ plenty of times, but doesn’t explain
what it means.
The second change I would like to see if the ability to delete image
straight from iPhoto. When you hit delete, to remove your duplicates, it
will remove the images by opening up iPhoto and then moving them to the
trash. You then have to manually delete the images, again, in iPhoto.
It is a little bit of a pain, since iPhoto takes so long to open up, and
then having to delete the image. I suspect this is a technical reason
this isn’t implemented.
I do like this app, it works really well and under the hood is
written to utilise the abilities of your Mac. I was amazed it was using
all 8 cores of the system. It is very useful and although there are some
problems I can see these being resolved.
The app costs $9.99 and is available from the
App Store. Bargain. There is a demo available from there site.