Somin on photo resizing

| Comments (9) | Misc
Over at Volokh, Ilya Somin recently asked:
I recently bought a digital camera, and used it to take numerous photos on a trip abroad. To my considerable annoyance, after I returned I learned that digital photos are formatted to be 4.5x6 inches rather than the standard 4x6. As far as I can tell, after calling up several photo shops, my only two options are either to 1) have the pictures cropped to 4x6 (which might eliminate important material, or 2) pay a fairly high price ($0.39/photo, even for a Ritz member like me) to have Ritz Camera develop them in 4.5x6 (the other shops I called don't develop in 4.5x6 at all). I realize that I could manually crop the photos on my computer. But that's not a realistic alternative because there are too many of them and I'm not good at cropping. I bet that many VC readers probably know more than I do about digital cameras (not a high bar to clear, to be sure). So here's my question. Is there any way I can do one of the following:

1. Have the pictures resized to 4x6 WITHOUT cropping of either the automatic or manual variety - and at a reasonable price.

2. Have them printed at 4.5x6 at a price significantly lower than Ritz's (20-25 cents/photo or less would be acceptable).

I suspect that I'm not the only person who has encountered this problem with digital photos. So I'm hoping that someone more savvy about digital cameras than I am has come up with a good solution.

His commenters then spend a bunch of time explaining to him that you can't convert 4.5x6 to 4x6 (a ghastly aspect ratio by the way) without either (1) letterboxing (though in this case it's pillar-boxing) or (2) cropping or (3) changing the aspect ratio, which you don't want to do. It doesn't take any knowledge whatsoever of digital photography or photography at all to convince yourself of this. Just imagine the image as printed on a rubber sheet and think about what happens when you stretch it in any one dimension. You can't simultaneously have the same framing that you originally wanted without also introducing image distortion. In this case, the distortion is quite bad, because 4.5 is 12.5% bigger than 4, and a 12% shrink is very noticeable.

Here's a demo of what this all looks like with a picture that's vertically rather than horizantally oriented.

OriginalLetter-boxedCropped (centered)Resized

Somin then follows up with another post that suggests that he still doesn't get it:

Thanks to all who responded to my bleg on digital photo resizing. Pursuing one of the suggestions offered by commenters, I have downloaded a digital photo resizing program. Unfortunately, the resizing options are listed in terms of pixels rather than inches (i.e. -640x480 pixels instead of 4x6 inches). My question for you experts out there (or just those whose ignorance is less profound then mine): What pixel option should I choose to resize digital 4.5x6 photos to the standard 4x6, so I can then print them out in 4x6 size without cropping (my original objective)?

As previously noted: this means he has to pillarbox, not resize. Resizing won't do anything for him. Moreover, this can't be done by typing in pixel options. He needs to make a canvas with a 4:3 aspect ratio and then copy and paste a smaller version of the 1.5:1 aspect ratio image onto it.

I do find it a little puzzling that Somin seems to find this so hard to grasp. Is aspect ratio simply a difficult concept? Are people so dazzled by PhotoShop that they don't think about what they're actually asking the computer to do? I'm trying not to make generalizations about a legal versus technical education, but this seems like sort of a basic concept. I don't get it.

9 Comments

Actually, my understanding is that Ilya has a 4:3 aspect ratio image and is trying to either convert to a 2:1 (not the other way around, as you suggest) for printing 4x6in photographs at a standard photo shop, or find a place that prints 4.5x6 at around US$0.25 per image.

In any case, my guess is that Ilya understands the concept, but doesn't use the language well. I think what was apparently being asked was a way to pillarbox a large number of images in a batch, which to a layman could well look like a "resize" -- after all, in common parlance, the size did change; it's just that borders were added as well.

In fairness, most people are just as likely to misuse legal terms.

Just like to point out 4x6 is the same aspect as the iphone. Oddly, I find I sort of like this "ghastly" aspect ratio. It's slightly closer to the golden ratio than the typical 16:9 ratio. Probably something like "On Food and Cooking" can be references to prove that the golden ratio is the one and only beautiful aspect ratio. Personally I find the german pragmatism of sqrt(2):1 aspect ratio sort of appealing as it leads to such fine packing of mutli-sized prints on the same paper.

PS - My favorite photo is the the resized one. It's got such a nice pencil neck look to it. Perhaps printing all your 4x6.5 aspect ratio pints on 4x6 will be just what your fiends wants - as long as he oriented his camera based on if the subject in it were too fat or too thin, it should all work out just fine :-)

What's with the crossed arms? Aren't you supposed be holding a board with writing on it?

Bah. The dimensions of the internal film are irrelevant.

What Somin should do is attach to his camera an anamorphic lens that expands the width by 12.5%. Then performing the 4.5x6 to 4x6 aspect change will recover the original undistorted image. Panavision in reverse.

You may find this interesting:

http://www.youtube.com/watch?v=vIFCV2spKtg

Image Resize - demo - without cropping or stretching, but by deleting less important parts. I was fairly amazed by it, and I think it could probably handle the issue.

Ted: seam removal/addition doesn't work so well with things like people's bodies, where there isn't really anything you can remove without making it look funny. It'll trim out to blue background in the image above of our illustrious host here, but as you can see if you go to http://swieskowski.net/carve/ and plug in the URL http://rungie.com/~craig/ekr-4.5x6.jpg to stretch it, it's not so good once the obvious-to-remove bits are gone, when it's dealing with a human. When it's dealing with a landscape image where your human brain doesn't know if part of a rock has been stripped out of the image, then it's not a problem. When you remove part of EKR's face, it's not so pretty...

I've found to my surprise that many people are quite insensitive to the consequences of changing picture aspect ratio. For example, I know several people who watch 4:3 aspect ratio TV shows on their 16:9 widescreen TVs only after poking the format button until they are in widescreen mode. It seems that they find the fact that people look a little fatter less upsetting than the black bars they would get otherwise.

Maybe he just doesn't care about the distortion.

You added the legal note - I don't find it surprising, really. Technical people look as physics, legal people look at text. I'm somewhat in the middle (consultant that helps with lots of things with legal implications), but prefer to look at physics, when there's the option

That said, I'm not sure why Somin doesn't just post-process - the rest us do. You don't need to buy (or pirate) Photoshop - every camera I know of offers software to crop, correct white-point, deal with balance, etc.

I guess, put a different way, go get a point-and-shoot if you don't want to fuss over the results. Photography may not be law, but it does take skill, will, and application. Nice shots don't come for free.

It looks in that last photo like your head has gotten a bit squeezed in a vice. Maybe you should get that checked out by your doctor.

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