The Cellar - Photography 101

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Quote:

Originally Posted by BigV (Post 738107)

An update on my journey with Picasa.

I continue to use this program as my principal image indexing tool. I also use it for lightweight editing, mostly straightening, exposure corrections, cropping, etc.

But it has a feature I really love and I'm using more and more. As I've said before, I am mostly just a snapshotter, and my favorite subject is people. I won't embarrass myself by calling pictures with faces in them "portraits", they're not. But they do have faces and Picasa knows this. It has a feature called face detection. This is pretty cool. It can scan a photo and pick out the section of the image that (according to its rules) is a face. It has made a couple (out of thousands) of mistakes, but mostly it's pretty "smart". It shows a crop of the face of a given image, resized so the face fills a thumbnail and then gives you a chance to add the photo to a special kind of album called a people album. In a shot that has more than one face, it will detect all the faces, show each of them in a thumbnail, and give you a chance to add that picture to each of the corresponding people albums.

A word about albums. An album is a collection of pictures. In Picasa, albums work like tags. A picture can belong to more than one album by having more than one tag associated with it. When viewing an album, all the pictures in it are selected from the database and shown as a collection. People albums, or People, work just the same. They're albums that have the title of a person's name, containing images that have been detected by Picasa to contain a face.

Back to People and faces. Not only does Picasa have face detection, it also has face *recognition*. This is scary cool. Once you've seeded Picasa's People albums with a few (or more) examples of a given face, it will continue to scan through the library looking for faces that match the ones already associated with a given person. When it finds some it *recognizes* it will suggest them to you. "Do these faces belong in this People album?". It's awesome.

Some of the the things you can do with this is to click on a Person, and see all the pictures that have that person in them. Also, there's a function called Face Movie, where the contents of a People album can be used in a special kind of slide show where the slides are put together in a face aligned movie. Here's a youtube video of Picasa's demo of this function. I think their model looks a bit like little Miss York at the beginning.

At this time, I have 214 People. And I have 18,875 faces detected but not yet categorized. It's a LOT. And it feels like pushing back the tide, but I take bites at it as I go, I think I'm making more forward progress than backward, so I carry on. Here's a typical screenshot of what I am making my way through.

I've circled a couple points of interest. SonofV appears in the blue circles. The red circles identify a couple interesting shots, one is a mask, not really a face, I'll throw that one away. The others show really dark faces in these thumbnails. I can double click on any of the thumbnails and get the whole picture, from which I might be able to recognize the person given the context. And the yellow circle in the upper right surrounds the slider showing how many screensful of this work I have ahead of me. Fun!!

Quote:

Originally Posted by classicman (Post 744959)

WTH are you doing anyway? How are you "identifying" all these peoples faces?

here's the long answer I don't wish to repeat.

Picasa has the ability to detect a face in a given shot, and I can identify that face. Once I've done that I can find that picture and that face easily. Have you any experience with face / tagging photos on facebook? Same kind of thing. I'm working my way through my whole collection of photos, and as I near the end here, the quality of the images Picasa has detected faces in are older, and crappier. It's exhausting work concentrating on screensful of faces and deciding who is who and who is I don't give a shit.

I *really* want to finish this project. And when I do, I want to extract the sets of pictures that contain the face of a given kid (mostly kids from family pics, scout trips, little league games, etc) and then compile them into a movie, or just the whole "album" of shots and give it to the family. I've got about ten years worth of pics here and seeing them grow up on screen has been immensely pleasurable. I think the parents of the other kids would enjoy them too.

ps--I see the screenshots I posted originally didn't make it into the quote. whatever. Go back and look at post # 60 in this thread for a visual of what I'm dealing with.

ok, gotcha. That sounds pretty cool.

1,195

I am going to finish this batch today.

I don't want to be a wet blanket, but I want to caution you about one thing:

Please be very sure that each and every one of the parents that you present with movies made out of hundreds of pictures centered on their kids understands very clearly that you are not stalking their little angel, or you will end up on a list and have to deal with a crap load of......crap.

^^^ wut he said ^^^

The world is a fucked up place and you gotta cover yer ass.

disclaimer:
Unless you are stalking their kids.
In which case go ahead and send the movies to everyone and ....
<jus kiddin>

good point jim.

you may be assured that I know each family personally, and have been friends with them for years. That's how I've managed to accumulate the pictures in the first place. That's no magic shield against crap of course, but anyone that's not digging the program isn't there. And indeed, I've had to sign photograph releases at some of the established summer camps. Regardless. I'm not stalking anybody's kid. Anybody's kid I have a picture of, that parent brought the kid to the bus and sent them off to camp with me and the other adults.

I don't think I've made clear how I came to have these pictures, but you can be sure, every one of them was taken with the implied consent of the parents.

I've scanned through the faces again and the pictures with identified faces. What I found is that there are LOTS of pictures that have *some* faces identified and others equally visible, indeed, faces of people recognized in other photos, that aren't detected by Picasa.

So. I've rescanned the whole collection, and the first total after this second scan produced almost 50,000 unidentified faces. That number is down to 28,005 now.

A neat trick I learned by accident has to do with a couple of sliders in the program. One slider is used to zoom into the picture. When you grab the slider, you can drag it to the right for increased magnification. There's another slider up at the top that is used to filter by date the pictures shown. I've used this second one a lot to reduce the working set of pictures with faces I have to make decisions about. As I dragged the slider to the right, it filters out older pictures. The further to the right I drag it, the set of pictures displayed is smaller and newer. This is useful, but difficult to manage the slider one pixel at a time, because the time scale is not strictly linear. And at the oldest ranges, I might make a tiny physical change and have the time threshold change by a year. At the right hand side of the scale, the same physical distance on the slider might represent a much smaller time delta, perhaps only one month. Making tiny changes at the older ranges was tough.

Then, I accidentally moved the cursor over the slider *and* accidentally rolled the mousewheel as the cursor was over the slider range and the slider moved one increment with each wheel detente I turned through! This is awesome! I tried it up at the top on the time slider, and it worked the same. So, now I can make the most granular changes to the time scale. This lets me divide the pictures into sets that are more easily understood since I take them in batches. Seeing them all together makes it harder to identify the faces since I have to shift contexts for faces I don't immediately recognize. I'm happy I found this kind of control in the interface.

Oh, and I should have mentioned that this is a pretty cool idea... looks like a lot of work.

The genealogists of the future, in your family at least, may have an easier time of it because of this time you're spending.

Thank you jimhelm. :)

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