Wikipedia:Reference desk/Archives/Miscellaneous/2014 March 29

= March 29 =

Why are news organizations blurring the images they post on their websites?
Lately, I've noted that many images on the websites of news organizations are unsharp. Obviously, journalists with $10,000+ super duper DSLR cameras are not all such incompetent photographers that they cannot take reasonably sharp images. An image posted on the BBC's website today was large enough (pixelwise) that it allowed for approximate deblurring, see here. As I explain there, there is an artifact in the image that suggests that the image has been deliberately modified.

But what is unclear to me is why they want to blur their images. Is there some copyright issue here? Count Iblis (talk) 03:44, 29 March 2014 (UTC)


 * The photograph appears to be taken from a moving aircraft, through a window, through weather, of moving sea, using unknown photographic equipment. I don't think that translates into deep insights about what photographers can do.
 * "Enhancing" will introduce artifacts that aren't there - an image processing algorithm that displays information that isn't in the original image is necessarily making it up. Try "deblurring" some pictures of clouds and see if you'll find writings from the gods in there. 88.112.50.121 (talk) 12:24, 29 March 2014 (UTC)


 * Military Reconnaissance satellite pictures of possible wreckage of the missing Malaysia Airlines Flight 370 are being released by countries such as China, France and Thailand whose exact survellance capabilities are usually kept secret. It is likely that any images released to the press are first processed by the national authority to avoid revealing the raw resolution obtained. Once an image is digitized in a compressed format, such as JPEG in the OP's example, there is little extra detail that can be extracted by Unsharp masking or Richardson-Lucy deconvolution methods of image enhancement. 84.209.89.214 (talk) 16:03, 29 March 2014 (UTC)


 * This depends on the level of compression. As long as the image is severely blurred compared to the pixel resolution, you can extract hidden details. Note that unsharp masking is not going to help here, because this only enhances the contrast of the small scale features that are already visible in the original picture. Richardson-Lucy deconvolution is able to recover the small scale details that are now hidden in longer scale structures due to the blurring (these details are not lost, they are still present in the image, albeit degraded to some extent due to noise and the finite image resolution). The fact that there is always noise will prevent perfect deblurring even if you have exact knowledge of the point spread function. E.g. a perfect isolated point can have become an isolated disk that an unsharp mask can make smaller. But two nearby points will lead to two disks that are merged. The unsharp mask then won't resolve the two separate point anymore, it will simply enhance the contrast of the edge of the visible structure. Deconvolution, in contrast, can restore the orginal image to a good approximation. Count Iblis (talk) 18:01, 29 March 2014 (UTC)


 * I agree with 88 here, while I have no idea what other photographs you're talking about here, it sounds a lot like you're reading way too much in this particular photograph considering what we do know about it. Note that the BBC source says it's from a journalist. This doesn't rule out the source being a press photographer (since they would usually be called journalists in a lose sense), but there still seems to be great interest in this story among the press which likely means that there's a great deal of competition to get on the search planes. I'm fairly sure the S&R people on the planes themselves don't want the distraction of journalists and press photographers so there's a fair chance only a few of the flights carry journalists of any sort. So it's hardly surprising given the competition etc that some media organisations only get to send one person one the flights and this person is generally someone more in the writing field than in the photography field. While most journalists would probably be a better photographer than the average person, their expertise is generally likely to be a lot less than a professional photographer and considering all the other conditions outlined... Nil Einne (talk) 01:35, 30 March 2014 (UTC)


 * I'm just a regular Joe with a regular job, but that "suspicious artifact" seems like a wheel. And sometimes that just ain't enough to keep a man like me interested. Of course, maybe you're right when you tell me I'm wrong... InedibleHulk (talk) 16:31, 29 March 2014 (UTC)


 * Also looks like a mouse cursor indicating zoom - you know, a magnifying glass with a + or - in the middle. A bit of "deblurring" should cheerfully turn that into a wheel. Are we looking at a snapshot of a shaky cell phone video being edited in Photoshop? 88.112.50.121 (talk) 19:28, 29 March 2014 (UTC)
 * A-ha! Good idea. I formally withdraw my wheel theory. But I stand by Leary's theory that going out and having fun at other people's expense makes one an asshole. But they can be proud of it. InedibleHulk (talk) 18:00, 30 March 2014 (UTC)
 * To me,it looks like a buoy which even casts a nice little shadow, rather than a wheel or a magnifying glass. Nice 04/01 edit, Hulk. Nice oxymoron in the external link, too: "American Pie star". ooze 05:28, 1 April 2014 (UTC)

Salmon spawning
Salmon smolt born and raised in a hatchery are released and then travel to the ocean and eventually (hopefully) return to fresh water to spawn. How does this hatchery born salmon know where to return? That is, surely it does not return to the hatchery; and unlike its natural born cousin, it does not have the born instinct of 'place of birth' to return to complete its life cycle. So I wonder, how does that hatchery born adult salmon know the place of origin to which it must return to spawn?184.167.254.25 (talk) 14:00, 29 March 2014 (UTC)


 * NPR just mentioned this in a story a few days ago. Dismas |(talk) 14:12, 29 March 2014 (UTC)
 * The amazing abilities of Pacific salmon to migrate long distances from the ocean to their natal streams for spawning have been investigated intensively since 1950's, but there are still many mysteries because of difficulties to follow their whole life cycle and to wait their sole reproductive timing for several years. This field study demonstrates that coho salmon imprint to and utilize chemical cues for homing. See also. 84.209.89.214 (talk) 15:34, 29 March 2014 (UTC)