[magick-users] controlling the amount of noise added to image with Image::addNoise (magick++)

[Anthony Thyssen]

Micha Feigin on  wrote...
| On Sun, 22 Apr 2007 15:49:40 -0700
| omicronpersei8 at imagemagick.org wrote:
| 
| > > The problem is that image magick adds way too much noise and I can't seem 
| > 
| > Did you try using a different type of noise?  You can choose from uniform,
| > gaussian, multiplicative, impulse, laplacian, and poisson.  ImageMagick has
| > built in constants associated with each noise type.  We could make the
| > constants a parameter to the noise method.
| > 
| 
| yes, except for poisson which does virtually nothing, all the rest leave me
| with noise with no image.
| 
| Besides, the type of noise is important for most applications.
| 
| Seems like I need to hack the imagemagick code.

No need to go that far...

The -fx function can add noise in a some way you specify.
For example a random offset, to each color...

   convert rose: -fx 'u+random()*.2-.1' rose_noisy.png

However you are probably right about the lack of control with noise.
A number of very old option did not get the control that they should
have had, which is now giving us problems.  the question is exactly
what type of control is wanted.


  Anthony Thyssen ( System Programmer )    <A.Thyssen at griffith.edu.au>
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