If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Noise in digital picture
There has been some ongoing discussion about noise in digital pics and the
general assumption is that it is a "bad thing". Camera manufacturers work hard to eliminate it, as discussed in the recent posts over the FZ30. However, I came across a blog today which cites an academic paper suggesting that noise can also be your friend. I have pasted the blog below, followed by a link to the paper. The comment about the possibility that Canon "build in about the right amount of noise" is something that Panasonic might take on board. Bill PS The blogger is an architectural photographer based in the UK. ~~~~~~~~~~~~~~~ quote This [see URL below] is an academic paper on the perception of sharpness in digital photographs. I find this fascinating because it confirms a belief that I have developed about why images scanned from film can still look better than a digital image of apparently the same number of megapixels. To my eye, digital images look unnaturally smooth as they lack the grain which is exhibited by film. This paper suggests (among other things) that adding a small amount of fake grain to a digital image can enhance its perceived sharpness. This is apparently quite an astounding discovery, because adding "noise" using a tool like Photoshop, will in a strict sense reduce the amount of correct information in the image. This is astounding to all but psychologists of perception who know only too well that human perception is a construct that overlays our preconceptions over the data we receive from the outside world. In this case, the human perceptual system appears to be fooled into thinking that the extra random information which results from adding noise or artificial grain to an image, is actually real information. The amount of noise which needs to be added is actually rather subtle and unfortunately this paper lacks enough detail about what kind or intensity of noise was actually added. As a result, I can't see how it would be possible to replicate their experiment accurately to confirm their results. I assume that if this paper is eventually peer reviewed and published, that this shortcoming will be addressed. I've found that its possible to use Photoshop to add noise to achieve an apparent improvement with a variety of digital file sizes from 6-39 Megapixels, and I have a theory that Canon engineers build in about the right amount of noise (or rather let about the right amount through their noise reduction algorithms) in the case of the 1DsII flagship camera. Unfortunately the built in filters provided by Photoshop don't have the most agreeable effect to my eye, I prefer proprietary third part software which allows for more subtle and film grain like effects. unquote http://www.cis.rit.edu/people/facult...PDFs/PRO12.pdf |
#2
|
|||
|
|||
Noise in digital picture
Bill Again wrote:
There has been some ongoing discussion about noise in digital pics and the general assumption is that it is a "bad thing". Camera manufacturers work hard to eliminate it, as discussed in the recent posts over the FZ30. However, I came across a blog today which cites an academic paper suggesting that noise can also be your friend. I have pasted the blog below, followed by a link to the paper. The comment about the possibility that Canon "build in about the right amount of noise" is something that Panasonic might take on board. Bill But noise can also be ugly, jagged, nasty blotchy and totally unlike film grain. -- Paul (This sky, too, is folding under you) ------------------------------------------------------ Stop and Look http://www.geocities.com/dreamst8me/ |
#3
|
|||
|
|||
Noise in digital picture
"Paul Heslop" wrote in message ... Bill Again wrote: There has been some ongoing discussion about noise in digital pics and the general assumption is that it is a "bad thing". Camera manufacturers work hard to eliminate it, as discussed in the recent posts over the FZ30. However, I came across a blog today which cites an academic paper suggesting that noise can also be your friend. I have pasted the blog below, followed by a link to the paper. The comment about the possibility that Canon "build in about the right amount of noise" is something that Panasonic might take on board. Bill But noise can also be ugly, jagged, nasty blotchy and totally unlike film grain. -- Paul (This sky, too, is folding under you) Exactly true. But this paper is suggesting that in other circumstances it can actually add something to the picture. It is important in this respect that we do not perceive it as "noise" but that, psychologically seen, we subconsciously perceive it as enhancing the picture in some way. *That* is what I found interesting, not the blotches. Bill |
#4
|
|||
|
|||
Noise in digital picture
Bill Again wrote:
"Paul Heslop" wrote in message ... Bill Again wrote: There has been some ongoing discussion about noise in digital pics and the general assumption is that it is a "bad thing". Camera manufacturers work hard to eliminate it, as discussed in the recent posts over the FZ30. However, I came across a blog today which cites an academic paper suggesting that noise can also be your friend. I have pasted the blog below, followed by a link to the paper. The comment about the possibility that Canon "build in about the right amount of noise" is something that Panasonic might take on board. Bill But noise can also be ugly, jagged, nasty blotchy and totally unlike film grain. -- Paul (This sky, too, is folding under you) Exactly true. But this paper is suggesting that in other circumstances it can actually add something to the picture. It is important in this respect that we do not perceive it as "noise" but that, psychologically seen, we subconsciously perceive it as enhancing the picture in some way. *That* is what I found interesting, not the blotches. Bill I've had a couple that looked okay with the 'noise' level and I agree about the grain thing, but noise can be awful and sometimes adjusting, say, a darkening sky in an image can show immediately just how bad that noise is. This is I would say with film grain it doesn't affect the detail, where noise can degrade the image around the edges of lines etc. -- Paul (This sky, too, is folding under you) ------------------------------------------------------ Stop and Look http://www.geocities.com/dreamst8me/ |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
ISO 200000 ? | Gene F. Rhodes | Digital Photography | 113 | February 4th 06 05:58 PM |
Digital Stock /Footage & Clips CDs, updated 24/Jan/2006 | [email protected] | Digital Photography | 8 | February 3rd 06 04:00 AM |
[LONG] Theoretical estimates for film-equivalent digital sens | Ilya Zakharevich | Digital Photography | 52 | April 9th 05 09:06 AM |
How to Buy a Digital Camera | [email protected] | Digital Photography | 6 | January 18th 05 11:01 PM |
Digital Imaging vs. (Digital and Film) Photography | Bob Monaghan | Medium Format Photography Equipment | 9 | June 19th 04 05:48 PM |