"Paul Smith" on  wrote...
| Dear All,
| 
| I have got a colored scanned TIFF image from a newspaper article. Can
| ImageMagick be used to convert the color of the image background to
| white, with no loss?
| 
Do you want to adjust (color correct) the whole image?
Or just replace the background parts?

How much color variation is there in the background?

Does the background color also appear in the foreground image?

These are just some of the questions you need to ask to solve this
complex problem.

I don't have all the answers, and you could say I am still collecting
methods and solutions for IM Examples.

-----
Color Correction....

I have seen this recentlly in a image processing algorthms book,

It involved selecting a number of background points which is used to
generate a gradient image consisting of just the background colors.
This was then used to color adjust the whole image (including the
foreground) to subtract the lighting, environmental and printing
color distortions from the whole image.

IM should be able to do it, but I am not certain on the exact process on
how to do it at this time.

Some examples of this (but only using an average image color)
is on the page...
   http://www.lsus.edu/sc/math/rmabry/imagemagick/avgdemo/

----
Background removal....

The alturnative is to ignore the color distortions and select and remove
just the background from the image.

The simplest way if to try and create an image of the appropriate
background color and using a 'fuzz factor' mask that color from the
original image, using a recentally added composition method called
'ChangeMask'.

See IM Examples...
  Channels, Masks, and Transparency
    http://www.imagemagick.org/Usage/channels/#mask_creation

Yes this is still incomplete, but it is getting there.

---------
An alturnative that is under development is
gradient color replacement

See http://www.lsus.edu/sc/math/rmabry/imagemagick/multireplace/


  Anthony Thyssen ( System Programmer )    <[EMAIL PROTECTED]>
 -----------------------------------------------------------------------------
                 To think is human, to compute, divine.
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     Anthony's Home is his Castle     http://www.cit.gu.edu.au/~anthony/
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