removing digital noise through Photoshop


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#1
some of my recently taken pics got loads of digital noise though light is very sufficient...how do i remove it ?
 

stroma

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#3
acetylcholine said:
some of my recently taken pics got loads of digital noise though light is very sufficient...how do i remove it ?
Try this - Select filter> Gaussian Blur and set to about 10 or so - or until noise is indestinguishable !! Great so now you have an out of focus photo...
Now the clever bit.. Under edit select Fade Gaussian Blur (You must do this immediately after applying the blur, leave the opacity at 100% but change the blend mode to 'colour' - the worst of the noise will disappear.
 

chriszzz

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#4
acetylcholine said:
some of my recently taken pics got loads of digital noise though light is very sufficient...how do i remove it ?

I use NeatImage. Download ( or create your own ) noise profile for your specific camera model and ISO. Works better than "generic" noise removal. NeatImage has a free version, and it works just fine. Try it !
 

Hoky

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#5
stroma said:
Try this - Select filter> Gaussian Blur and set to about 10 or so - or until noise is indestinguishable !! Great so now you have an out of focus photo...
Now the clever bit.. Under edit select Fade Gaussian Blur (You must do this immediately after applying the blur, leave the opacity at 100% but change the blend mode to 'colour' - the worst of the noise will disappear.
Is this the best way to remove noise in PS??
Is there's any other better techniques?
 

khairi

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#7
acetylcholine said:
some of my recently taken pics got loads of digital noise though light is very sufficient...how do i remove it ?
yo yo...Stroma's method is pure PS style...pros do such method.

Neatimage is a third party software...a lot of CS members recommend newbies this software...try it.
 

coke21

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#8
Hoky said:
Is this the best way to remove noise in PS??
Is there's any other better techniques?

There are other methods but they can be quite lengthy. What stroma suggested was a quick and effective way. You can try this if you have the time:

1) After opening image go to image menu, under mode, choose Lab colour and switch to lab colour
2) Go to the channel palette an you will see 4 channels. Lab, lightness , a and b
3) select the a channel and apply a bur filter, gaussian blur until you see the noise disappear.
4) choose the b channel and use ctrl-F This will apply the same settings to b that you did in a.
5) Go back to image mode and return to RGB mode. The image should be improved.
 

2100

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#9
Neat image. :thumbsup: Fast too with version 4 (it was really slow then). If you really need it for some use, get it (only USD 29.90). Actually, the demo version works the same too, just that it saves jpgs into like Normal quality jpeg. Eg, 2MP file originally is 700kb, now it's 300kb. But still looks really good.
 

coke21

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2100 said:
just that it saves jpgs into like Normal quality jpeg. Eg, 2MP file originally is 700kb, now it's 300kb. But still looks really good.
]

Looks good on the montior. But if you need to print it out, don;t think its gonna look at all good.
 

2100

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coke21 said:
]

Looks good on the montior. But if you need to print it out, don;t think its gonna look at all good.
Have you printed it out, using the demo version? I use the registered version, so no idea on how bad it gets. It does look good enough on the monitor. Of course, don't expect bigger than 5R sizes.

Anyway, one fallacy people have is that they whack the NR all the way up to 100% and expect ISO 1600 to become ISO 200. Yes, the grain may drop to that level, but the overall pic quality can't. I usually set mine to 40-50%,
ISO 1600 > ISO 800, i am happy. :)
 

coke21

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#13
2100 said:
Have you printed it out, using the demo version? I use the registered version, so no idea on how bad it gets. It does look good enough on the monitor. Of course, don't expect bigger than 5R sizes.

Anyway, one fallacy people have is that they whack the NR all the way up to 100% and expect ISO 1600 to become ISO 200. Yes, the grain may drop to that level, but the overall pic quality can't. I usually set mine to 40-50%,
ISO 1600 > ISO 800, i am happy. :)

No I don;t use that software but looking at the image size, 300Kb, I'm pretty sure the resolution when printing is not going to be good.
 

stroma

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#14
coke21 said:
There are other methods but they can be quite lengthy. What stroma suggested was a quick and effective way. You can try this if you have the time:

1) After opening image go to image menu, under mode, choose Lab colour and switch to lab colour
2) Go to the channel palette an you will see 4 channels. Lab, lightness , a and b
3) select the a channel and apply a bur filter, gaussian blur until you see the noise disappear.
4) choose the b channel and use ctrl-F This will apply the same settings to b that you did in a.
5) Go back to image mode and return to RGB mode. The image should be improved.
This is a very good method that works quite well on noisy originals and is virtually identical to the method I mentioned earlier in that it only applies blurring to the colour elements of a photo and not the greyscale which gives the definition that would otherwise be lost.

On the other side of the coin using Lab mode for sharpening is also a reasonable technique e.g blur channels a and b to remove excessive noise and then apply a USM to the lightness channel to sharpen.... (As this doesn't introduce colour artefacts) .. but there are better ways still....

Having said all that, personally I use both Neat Image and Helicon for all my noise reduction. Each gives better results than the other at different times. Neat Image can still be very slow and leaves occasional untouched artefacts in the middle of well 'cleansed' image. Helicon in its present version is too unstable (Struggles with large files) but both are vastly superior to what can be achieved with any of PS's standard functions [The original Question was noise reduction in P :) S]

In general I don't take photos where high ISOs are required and therefore suffer little noise but still use both the above as they seem to give a film like quality to files originally generated from digital. I Don't use on scanned slides. ;p
 

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