161–170 of 249 posts
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Bokeh = shallow depth of field effects The author isn't the one confused.
Hi, I am the author of the Lens Blur blog post and the sentence was indeed wrong as a result of multiple edits. Bokeh and shallow depth of field are indeed two different things. By Bokeh we mean that the blur is synthesized using a disk kernel, e.g. as opposed to a Gaussian Blur. The blog is now fixed.
I sure wish you could buy a DSLR that just plugs into your iPhone. I don't want any of that terrible DSLR software -- just the hardware. I think many devices should become BYOD (bring your own device) soon, including big things like cars. edit: I don't just want my pictures to be saved on my phone. I'd like the phone to have full control of the camera's features -- so I can use apps (like timelapse, hdr, etc.) direct…
1) Samsung has released the Galaxy NX: a mirrorless interchangeable lens camera, which has a DSLR-sized APS-C sensor, but no actual mirror. The back is essentially just a big Android phone.
2) Sony sells the QX-10 and QX-100, which are just the lens, and you wirelessly connect them to your phone. The QX-100 has the same 1" sensor as the best pocket camera you can currently buy (the RX100).
3) Both Sony and Canon make wireless cameras (Canon 6D [full-frame], Sony RX100 MII [1" sensor] or A7/A7R [full-frame], maybe others), that let you connect to a phone or tablet and view a live feed of what the camera sees, change the aperture or other settings, trigger the shutter, and receive photos on your device. I'm unclear how open the Canon API is, but Sony has their own ecosystem of interesting apps (http://playmemoriesonline.com/) that let you do things like set-up time lapses. The Sony UI is pretty clunkly though, I would greatly prefer an open API.
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Those permitted edits you mention seem to all preserve the pixel-level integrity of the image. The fact that intentional blurring does not do this seems to be a distinction to me. I think that the fact that the blur layer must be synthesized heuristically indicates that not all of the information of the final image was really captured from the real world. I suppose that resizing (resampling) an image might be said to…
>Those permitted edits you mention seem to all preserve the pixel-level integrity of the image. Curiously, you're allowed to convert color to black and white, which in my opinion is not preserving the pixel-level integrity. An algorithm is making a guess at what level of black to convert a pixel to. > Question for professionals -- how are noise reduction, masks (unsharp), etc. treated? I'm not a pro yet, but my under…
Can you not just average the RGB values? Perhaps adjusting a bit for relative intensities of those values (I'm just guessing but red is probably less bright than blue or green). It's not really a "guess" is it unless it's a sophisticated algorithm. It's more akin to rotating or skewing an image.
Or you mean it's a guess compared to how non-colour film would actually record the light?
I believe the algorithm could be improved by applying the blur to certain areas/depths of the image without including pixels from very distant depths, and instead blurring/feathering edges with an alpha channel over those distant (large depth separation) pixels. For example, if you look at the left example photo by Rachel Been[1], the hair is blurred together with the distant tree details . If instead the algorithm d…
Occlusion boundaries are always a challenge for vision algorithms. The defects you see are probably due to incorrect depth estimates in these regions. My guess is that for efficiency on a mobile device, they are using a simple window to aggregate the SAD measurements rather than a more complex term which weights errors based on color similarity. The simpler method will not perform well at these boundaries. Getting co…
EDIT: Hard to say if this really is a problem with the depth map. In the right image (foreground in focus), the background blur seems to end pretty close to the hair boundary, if not somewhat inside the boundary of hair - the edge of the hair appears slightly blurred. If the depth map were simply inaccurate (with the same inaccuracy applied in both images), I'm guessing you'd see a portion of sharper background outside the hair boundary. I suppose another explanation would be some biased expansion/feathering of the blur mask.
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There have been multiple implementations of this class of algorithm (collectively "synthetic aperture") using different techniques. Edit: below mentions the HTC "double camera" phones, and in fact it's also possible to create synthetic aperture photography with multiple cameras instead of moving a single camera to multiple positions. Then you have the added advantage of not needing to assume a static scene! But a sin…
It looks like this isn't creating a synthetic aperture, it's just creating a depth map and applying a depth-dependent blur to a single frame.
Regarding the technology (achieving shallow depth of field through an algorithm), not Google's specific implementation ... Up until now, a decently shallow depth of field was pretty much only achievable in DSLR cameras (and compacts with sufficiently large sensor sizes, which typically cost as much as a DSLR). You can simulate it in Photoshop, but generally it takes a lot of work and the results aren't great. The "sh…
Regarding the technology (achieving shallow depth of field through an algorithm), not Google's specific implementation ... Up until now, a decently shallow depth of field was pretty much only achievable in DSLR cameras (and compacts with sufficiently large sensor sizes, which typically cost as much as a DSLR). You can simulate it in Photoshop, but generally it takes a lot of work and the results aren't great. The "sh…
Eh...$15 used 50mm f1.4 or F2.0 lens and $25 film body from KEH.com...
Regarding the technology (achieving shallow depth of field through an algorithm), not Google's specific implementation ... Up until now, a decently shallow depth of field was pretty much only achievable in DSLR cameras (and compacts with sufficiently large sensor sizes, which typically cost as much as a DSLR). You can simulate it in Photoshop, but generally it takes a lot of work and the results aren't great. The "sh…
Eh...$15 used 50mm f1.4 or F2.0 lens and $25 film body from KEH.com...
Earlier quoted context omitted.
> Also, I have to add that it differs for news reporting versus stuff like interview shots, travel shots etc. Right, it really depends on if the shot is being used for "news" or if it's just an artistic shot to fill space. That's why at the start of this whole thread I reference photojournalism.
> That's why at the start of this whole thread I reference photojournalism. I saw it, but it's not that clear cut. What you write, "an artistic shot to fill space" implies to me generic illustration pictures, which the above isn't an example of. I think the restrictions to editing are mostly contrained for photos about stuff like politics, world affairs, crime etc -- stuff that is presented as 100% dry news. But the…
I agree, and as I understand it, anything beyond some basic level/color adjustments and cropping is a no-no in those areas if you want to keep your integrity.