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Re: Point Sampling in Digital Image Processing?

  • To: mathgroup at
  • Subject: [mg57811] Re: Point Sampling in Digital Image Processing?
  • From: "Mariusz Jankowski" <mjankowski at>
  • Date: Thu, 9 Jun 2005 05:17:45 -0400 (EDT)
  • Organization: University of Southern Maine
  • References: <d869ab$cc8$>
  • Sender: owner-wri-mathgroup at

Dear Greg, there currently is no function with the exact functionality you
describe. However, this is easily accomplished - here is an example.

(* this reads the image *)

{r, g, b} = ToChannels[ImageRead[ some file ...] ]

(* construct an InterpolatingFunction object, default value for n is 3 *)

interRed = ListInterpolation[ RawImageData[r], InterpolationOrder -> n ]

(* sample *)

interRed[ Random[Real,{1,256}], Random[Real,{1,256}] ]

That is all, good luck,



>>> Greg Humphreys<humper at> 06/08/05 4:12 AM >>>
Hi -- I was wondering if the Digital Image Processing package has a
built-in function for point sampling an image at arbitrary coordinates
(e.g., non-integer coords), doing some sort of interpolation between
pixels.  I haven't found anything appropriate in the help.


    -Greg Humphreys

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