What are the types of noises in images and videos?

[qasmi]

Types of Noise in video?

What are the types of noises in images and videos?

Can image processing techniques can be directly applied to video processing?

What are the techniques that can be used to overcome noise in video?

 

[IanP]

Re: Types of Noise in video?

I work quite a lot with video signals, processing.... but so far haven't come accross classification of noises in video signals.
You just identify source of noise: low-light image noise (generated by gain circuit in cameras), emc noise etc.

First you convert analog (composite) video signal to digital (A/D) and then you can apply the same processing as for images.

How to reduce noise: software and hardware. More info on digital noice reduction you will find on **broken link removed**

 

[qasmi]

Re: Types of Noise in video?

Yes, I am processing Video in digital domain.

The noise I want to remove consists of black/white dots changing their position or location in the video. I am using B/W camera with 12-bit resolution. The resolution is not a problem, because when I capture a still image then it seems perfect and after processing does not enhance the noise. Processing such as edge detection, enhancement etc. requires this noise to be suppressed, but this noise become more visible after processing on video. I have used mean filter, median filter etc. but the video becomes worst after that.

I am using the Intensity part and processing it only. Since the camera is black&White, If Hue and saturation is also to be measured.

What are the sources of this variable noise and how can it be removed?

 

[IanP]

Re: Types of Noise in video?

For hardware pre-filtering you can try a nice IC from Maxim MAX7452. It is buffer/pre-amplifier with AGC and video filter (data sheet and free samples from Maxim web site).
You can also try digital video noise reduction with something such as: **broken link removed**

 

[gooodman]

Re: Types of Noise in video?

There are some kinds of artifact in DSC.

https://www.dpreview.com/learn/?/Glossary/Digital_Imaging/Artifacts_01.htm

 

[swahlah]

Re: Types of Noise in video?

The most popular noise is the camera noise in the video signal and it greatly affects the video compression and also other video processing techniques.
Other types of distortions may be due to atmospheric turbelance. Camera noise is not so easy to remove because you have to preserve the edges. If we apply a low pass filter to remove that noise then it may disturb the edges along the motion trajectory. Hence in applying any low pass filter you have to take care of the motion path and for this a simple motion estimation algorithm is required to be implemented and where the motion is negligible you apply your filter.
Another type of signal may be due to some particualr band of noise and it may be a repetative noise e.g. in case of JET planes. So there you have to apply a band reject filter to remove that particular band of noise.
Otherwise if your image is coming from a Stellite then the most important noise is white guassian random noise. Normally images are affected by salt and Pepper, and Guassian random noise..... but if u are thinking of source then definitly the camera noise is the typical guassian noise case in video signal.........
Here i am also attaching two documents on Noise reduction and it may help you alot in reducing the noise......... These are really usefull.
Sincerely,

 

[swahlah]

Re: Types of Noise in video?

In reponse to your second email that you are encountering the white and balck dots..... SO this is called the "SALT and PEPPER NOISE", as i mentioned in my previous email....... Now if you want to remove this noise the median filter is sufficient upto certain level of noise intensity but not for higher intensities of noise. i think you in your case the noise intensity is much higher.......
Why don't you use some image restoration technique to recover your video data ina clean fashion and then process it......... Averaging filter normally removes this noise but makes the video blurry............. You have to make a combination of Averagin filter and unsharp masking to get somehow better result or may be a more robust denoising filter but it will take more load............... One filter i can suggest is attached here with ........ I am using it in my video Encoder and it removes the noise greatly......... Remember if you use the noisy data in your video processing unit it will degrade the performance of your system...............
There are different equations of filter but you have to try each one and then pick one most suitable for you............
See the attached file...................