Mathematica 9 is now available
Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2009

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Problems combining new v7.0 Image command with other graphics

  • To: mathgroup at smc.vnet.net
  • Subject: [mg95150] Re: Problems combining new v7.0 Image command with other graphics
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Wed, 7 Jan 2009 07:12:10 -0500 (EST)
  • Organization: Uni Leipzig
  • References: <gjv732$ov0$1@smc.vnet.net> <gk1rj5$oq5$1@smc.vnet.net>
  • Reply-to: kuska at informatik.uni-leipzig.de

Sjoerd C. de Vries wrote:
> Hi Mac,
> 
> 1. What use would it have to use those image processing commands if
> not for displaying? 

Oh let me give you an example, you have found an object in your image,
but you want increase the outline of the object by say 10 pixels.
You would use a distance transform of the object and binarize the
distance map with a threshold <=10.
Clearly the distance is a floating point value, it is *not* in the
range [0,1], in the application above you will never see the distance
map and you *not* display it. Moreover display it with ImageAdjust[]
will rescale the distance values and destroy all useful information,
because after the rescaling you can't set the threshold for the 
binarization.

> 
> 2. I agree that would be nice, but it doesn't seem to be there. At
> least you can fake it. Look, for instance, at this demonstration:
> http://demonstrations.wolfram.com/ProcessingVariousPartsOfAnImageDifferently/
> 
> 3. You can combine bitmapped Images with vector based Graphics using
> ImageCompose:
> 
> ImageCompose[Image[img], Graphics@Circle[]]
> 

That destroy the vector information and work with the
full image. Try to move a Locator[] object on the image
in that way, and not with
Graphics[{Image`ToGraphicsRaster[img][[1]],Locator[p]}]

BTW Image`ToGraphicsRaster[] seems to be the most useful function of
the image processing, because it restore the old bitmap format.

Regards
   Jens


  • Prev by Date: Re: Problems combining new v7.0 Image command with other graphics
  • Next by Date: Re: Animation = Translation + Vibration, But How?
  • Previous by thread: Re: Problems combining new v7.0 Image command with other graphics
  • Next by thread: Re: Problems combining new v7.0 Image command with other graphics