“UbuntuHelp:Photos/RemovingNoise”的版本间的差异
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{{Languages|UbuntuHelp:Photos/RemovingNoise}} | {{Languages|UbuntuHelp:Photos/RemovingNoise}} | ||
#title Removing Noise from Photos | #title Removing Noise from Photos | ||
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Noise is the presence of unwanted dots of color randomly distributed around a photo, resulting in a speckling effect. Due to its random nature, it is difficult to remove noise. However, it is possible to reduce its impact in a photo. | Noise is the presence of unwanted dots of color randomly distributed around a photo, resulting in a speckling effect. Due to its random nature, it is difficult to remove noise. However, it is possible to reduce its impact in a photo. | ||
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''See [http://en.wikipedia.org/wiki/Image_noise Wikipedia] for more information on noise.'' | ''See [http://en.wikipedia.org/wiki/Image_noise Wikipedia] for more information on noise.'' | ||
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=== Using the NL Filter === | === Using the NL Filter === | ||
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The ''NL Filter'' will typically remove most noise, but reduces the sharpness of the photo at the same time. See below for an example. | The ''NL Filter'' will typically remove most noise, but reduces the sharpness of the photo at the same time. See below for an example. | ||
| − | + | # Open a photo in the ''GIMP Image Editor'' | |
| − | + | # Press '''Filters''' -> '''Enhance''' -> '''NL Filter...''' | |
| − | + | # Set the ''Filter'' to ''Optimal estimation'' | |
| − | + | # Change the ''Alpha'' to a moderate value, around 0.50 | |
| − | + | # Change the ''Radius'' to a moderate value, around 0.50 to 0.70 | |
| − | + | # Tweak the settings to get the best results as seen in your preview | |
| − | + | # Press '''OK''' to apply the filter | |
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You may want to repeat this procedure a couple of times if you have a very noisy photo. | You may want to repeat this procedure a couple of times if you have a very noisy photo. | ||
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''See the [http://docs.gimp.org/en/plug-in-nlfilt.html GIMP Documentation] for more information.'' | ''See the [http://docs.gimp.org/en/plug-in-nlfilt.html GIMP Documentation] for more information.'' | ||
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==== Example ==== | ==== Example ==== | ||
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The photo on the left is the noisy original (the noise was actually added artificially for demonstration purposes). The photo on the right is the result after applying the ''NL Filter'' using the instructions above. | The photo on the left is the noisy original (the noise was actually added artificially for demonstration purposes). The photo on the right is the result after applying the ''NL Filter'' using the instructions above. | ||
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https://help.ubuntu.com/community/Photos/RemovingNoise?action=AttachFile&do=get&target=nlfilter.png | https://help.ubuntu.com/community/Photos/RemovingNoise?action=AttachFile&do=get&target=nlfilter.png | ||
[[category:UbuntuHelp]] | [[category:UbuntuHelp]] | ||
2007年11月30日 (五) 21:00的版本
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- title Removing Noise from Photos
Noise is the presence of unwanted dots of color randomly distributed around a photo, resulting in a speckling effect. Due to its random nature, it is difficult to remove noise. However, it is possible to reduce its impact in a photo. See Wikipedia for more information on noise.
Using the NL Filter
The NL Filter will typically remove most noise, but reduces the sharpness of the photo at the same time. See below for an example.
- Open a photo in the GIMP Image Editor
- Press Filters -> Enhance -> NL Filter...
- Set the Filter to Optimal estimation
- Change the Alpha to a moderate value, around 0.50
- Change the Radius to a moderate value, around 0.50 to 0.70
- Tweak the settings to get the best results as seen in your preview
- Press OK to apply the filter
You may want to repeat this procedure a couple of times if you have a very noisy photo. See the GIMP Documentation for more information.
Example
The photo on the left is the noisy original (the noise was actually added artificially for demonstration purposes). The photo on the right is the result after applying the NL Filter using the instructions above.
