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Photoshop 'unblur' leaves MAX audience gasping for air

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Re: Photoshop 'unblur' leaves MAX audience gasping for air

#32
post #24

It's called blind deconvolution. Blind means that they have to first estimate the original convolution/blur kernel and in the second phase, apply the deconvolution. If there's acceleration sensor on the camera, you can use data from that for the blur kernel. It's nothing new really, but algorithms for it have advanced tremendously. For example, there's some results from 2009 http://www.youtube.com/watch?v=uqMW3OleLM4…

I'm no expert in this so correct me if I'm wrong, but isn't a blur convolution only reversible ambiguously? You still have to perform smart guesses how to undo the average, right?

Re: Photoshop 'unblur' leaves MAX audience gasping for air

#33
If you are wondering how they might be doing it, here is one approach that I saw in a computer vision class (no idea if they are doing anything similar to this)

(slides: http://cs.nyu.edu/~fergus/presentations/fergus_deblurring.pd... (~60 MB ppt) paper: http://cs.nyu.edu/~fergus/papers/deblur_fergus.pdf (~10 MB pdf) )

The basic idea is that you have an unknown original image and it is convolved with an unknown blurring kernel to produce the observed image. It turns out that problem is ill-posed. You could have a bizzare original image blurred with just the right bizzare blurring kernel to produce the observed image. So to estimate both the original image and the kernel, you have to minimize the reconstruction error with respect to the observed image, while penalizing unlikely blurring kernels or original images. If one extracts enough statistics from a dataset of natural images, one can tell whether an image is likely or not by comparing that image's statistics to the corresponding statistics of your dataset of natural images. Similarly, simple blurring kernels are favored over complex ones (think "short arc of motion" vs. "tracing the letters of a word with your camera")

Re: Photoshop 'unblur' leaves MAX audience gasping for air

#34
post #19

The random anti-intellectual comments from the guys in the wheely chairs were extremely annoying and unfunny. This guy is there, showing something truly amazing, and they're all "What's an algorithm? Haha!". And they'll get away with it too.

It was funny. "This should be in the next version of Photoshop. Will I pay for it? No."

Re: Photoshop 'unblur' leaves MAX audience gasping for air

#35
post #24

It's called blind deconvolution. Blind means that they have to first estimate the original convolution/blur kernel and in the second phase, apply the deconvolution. If there's acceleration sensor on the camera, you can use data from that for the blur kernel. It's nothing new really, but algorithms for it have advanced tremendously. For example, there's some results from 2009 http://www.youtube.com/watch?v=uqMW3OleLM4…

One key problem with deconvolution is it's very susceptible to noise. I'm guessing they developed a way to ramp up the coefficients so you see an increase in clarity while keeping the noise below visible levels. So much of image (and audio!) processing is about getting away with noise the person can't detect :)

On a side note: does anybody know of workable deconvolution algorithms that vary the kernel over the image? The example would be compensating for a bad lens.

Re: Photoshop 'unblur' leaves MAX audience gasping for air

#36
post #5

I suppose this is more of image sharpening rather than reconstruction. Is this very different from technology on cameras/phones that tries to reduce of photo blurness due to unsteady hands?

What's the difference between "sharpening" and "reconstruction"? Both take an input image, apply some filter which is the best estimate of an inverse of a filter originally applied (e.g., wrong focus).

The technique to unsteady hands artifacts often has access to motion data, which this thing does not.

Re: Photoshop 'unblur' leaves MAX audience gasping for air

#37
post #23

Earlier quoted context omitted.

No, he's loading a different parameter file each time.

Either way, there's no point in watching a tech preview and being cynical about it.

I think there is. I much prefer cynicism to the blind adulation of "this tech is amazing and magical". Otherwise it's almost marketing spin.

Re: Photoshop 'unblur' leaves MAX audience gasping for air

#40
post #19

The random anti-intellectual comments from the guys in the wheely chairs were extremely annoying and unfunny. This guy is there, showing something truly amazing, and they're all "What's an algorithm? Haha!". And they'll get away with it too.

Rainn Wilson is actually a really smart guy. He was playing the classic stupid guy being wowed by a genius card, it was an actor's way of complimenting him.

Anti-intellectualism aside, they still interrupted an amazing talk without adding any value. An actor's way of dominating the stage even when it's not your turn. A bit rude and unnecessary.
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