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Behaviour of Mathematica varies according to size of digital image imported

  • To: mathgroup at smc.vnet.net
  • Subject: [mg80588] Behaviour of Mathematica varies according to size of digital image imported
  • From: Mac <mwjdavidson at googlemail.com>
  • Date: Sun, 26 Aug 2007 04:29:53 -0400 (EDT)

I'm using "Import" to read a stack of digital images into a list in
order to create an animation. However, the way Mathematica treats my
list depends on the size of the image - a strange behaviour which I
don't understand. The following is an example:

Case1: Using png or jpeg files with image size 96 x 256 (height,
width)

(* files is a list of the filenames to import - 10 images in my case*)
In[216]:= Clear[imglist]
imglist = Import[#] & /@ files ;
Dimensions[imglist[[All, 1, 1]]]

Out[218]={10, 96, 256, 3}


Case 2: Using png or jpeg files of any other width. I've tried images
of width 512, 257,255. Whenever the width is not 256 they all give the
same result

In[216]:= Clear[imglist]
imglist = Import[#] & /@ files ;
Dimensions[imglist[[All, 1, 1]]]

Out[218]= {10}

which is a real problem as I interpolate between the different images
to get a smoother animation. I've tried all sorts of tricks to get
around case 2 and get a list of image data as in case1 (using Apply,
Graphics-> List rules etc...) to no avail.

I'm using the latest Mathematica 6.0.1 and Windows XP SP2

I would be grateful for any help. It has taken me a better part of a
day to track down the problem.



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