# removing noise from images



## Mark Evans (3 Jan 2009)

now before i start this,this si not up to the standard of some of the others for showing different techniques and i've thrown this together really.

now these/ this image was taken a few months ago at...yes youve guessed it,....a boxing match!

i took near on 700 pics that night.

anyway, i always shoot 2 stop under when taking any picture generaly. the point of this si to show what can be achieved with an average shot (showing noise high iso etc) the down side to this post is its for RAW, but for JPEG users there are software programs that can eliminate noise etc....

i've took a snapshot of the image in my RAW editing software and pasted it into a PS document to show the sliders etc....

heres the original image as shot.....





as you can see the sliders are in there original position and the image quite dull.

now for the next image i've boosted certain sliders to show the noise  there are (if you look real close and compression has gone to work on this already) there are small green specks, hot pixels!!! on MY camera. this "noise" is on every photo, your mine everybodys, at high iso. BTW this was shot at 1250 .








theres more noise in this image than you can actually see.i think photobucket has somehow compressed the image reducing the noise, but it is there!

look at the above image and look at the sliders to the right....sharpness,noise suppression and hot pixel and pater noise suppression.
these are the power houses in RAW editing.

heres the same image after converting with the above settings.... you need to look REAL close, but you will see it. click on the image or save it and open in a program.









you can see how much noise, hot pixels....etc etc there is in an image when shooting at high iso hence the need to go as low as possible without ruining an image.

heres the final image after curves in PS and a gradient layed over the top (dark to light- top to bottom)

the feel of the picture determined a contrasty image which is what i like anyway.





jpeg users will have to nose about for software but it is out there, and for high end camera users shooting in jpeg...you should be ashamed of yourself


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## aaronnorth (3 Jan 2009)

The 2nd and 3rd pic looks exactly the same to me   Both have a similar amount of noise?


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## Mark Evans (3 Jan 2009)

i thought as much, the 2nd pic before up loading to photo bucket is covered. its after up loading it clears the image   i'll try and zoom in and up load new images.


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## Mark Evans (3 Jan 2009)

updated, it's the lack of smoothness in the image also. its still compressed though. 

when you want to show off badness you cant! ahhhh i want more noise


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## aaronnorth (3 Jan 2009)

saintly said:
			
		

> updated, it's the lack of smoothness in the image also. its still compressed though.
> 
> when you want to show off badness you cant! ahhhh i want more noise



Much better


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## Mark Evans (4 Jan 2009)

i kinda thought this was pointless when i read it through.

 at least it passed 20mins of a boring evening. maybe i could divulge my technique which includes PS gradient tool?


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## aaronnorth (4 Jan 2009)

How do you use curves? I read a guide online and it went straight over my head


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## Mark Evans (4 Jan 2009)

aaronnorth said:
			
		

> How do you use curves? I read a guide online and it went straight over my head



was it this one?

http://www.cambridgeincolour.com/tutori ... curves.htm

if you cant get your head around an online tutorial, i'm afraid anything i tell you wont be of any use. but it's well worth learning. even just the basics. thats all i use.

i don't think graeme will mind...I'll pm and check

here's why curves is good Aaron

Graeme's pic as he may see it....





and as I would view it.....





a simple crop and a slight curves adjustment. there's nothing wrong with either,hey some might even prefer the first one but 5 mins with curves can bring out colours and contrast in a really controlled way.

i use mainly curves and gradient tool for the above mentioned parameters


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## aaronnorth (4 Jan 2009)

Yes it was that one, i will just keep reading over it


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## Rob33 (4 Jan 2009)

Saintly:   'Curves' - is that the same as tone mapping?   My version of Photoshop doesn't have the curves function, but I think there is something like it in one of my Fuji programs (a RAW file editor).

Have you done any HDR?  I have seen some spectacular images (and plenty that are well weird).


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## Mark Evans (4 Jan 2009)

Rob33 said:
			
		

> Saintly: 'Curves' - is that the same as tone mapping?



TBH ive not heard of it. i've just googled it and it appears it for use with HDR? or create similar images. i've not used HDR sometimes i use the diffuse glow filter and high light contrast in my RAW editing software. which i think gives similar results


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## Dave Spencer (4 Jan 2009)

Tone mapping is a more "intelligent?" use of the basic curves. Both alter the tonal balance of an image, but as well dragging on a point on the curve, mapping also has sliders. In Lightroom 2.2 they are for Highlights, Lights, Darks and Shadows. The split point of each range of Highlights _etc._ can also be altered.

Basically, tone mapping is a method of using curves with a little more control. When I use curves I tend to end up with a fairly simple shaped "S" curve. Once you get your head around tone mapping you could end up with a more complex shaped curve.

Hope I have made sense.  

Dave.


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## Rob33 (4 Jan 2009)

Dave Spencer said:
			
		

> more "intelligent?"



I'd better keep well away then   

The "Digital darkroom" is a fascinating place - and a lot more user friendly than splashing about in chemicals  in the 'good 'ole days'


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## Themuleous (8 Jan 2009)

Great boxing photo 

Sam


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## Mark Evans (8 Jan 2009)

Themuleous said:
			
		

> Great boxing photo



thanks Sam, glad you like it


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## Ray (8 Jan 2009)

saintly said:
			
		

> was it this one?
> 
> http://www.cambridgeincolour.com/tutori ... curves.htm


Thank you Mark, your example with Graham's photo persuaded me to read the article, and now I finally understand what the histogram's I see everywhere mean and what iPhoto must be doing when I click "Enchance Photo"(?).  So curves allow us to tweak contrast differently across the entire spectrum, right?  Sort of anyway.


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## Mark Evans (8 Jan 2009)

Ray said:
			
		

> So curves allow us to tweak contrast differently across the entire spectrum, right? Sort of anyway.



i think so, something along those lines ray.. adjusting certain tones without adjusting others. once in curves click on any part of an image and you'll see the corresponding tone on the curves histogram.


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