Archive for the ‘Mathematica’ Category

How interpolation show their effect in frequency domain…

Sunday, September 9th, 2012

An interesting LinkedIn discussion brought on by Zhonghai Deng.  Here is my exercise displaying frequency plots for 2X interpolation via nearest-neighbor, linear, and cubic.  The original image is a rect function (10 pixels x 1 pixels)  All interpolated images are scaled 2X to (20 pixels x 1 pixel) with Adobe photoshop.  See the result sinc function comparison and/or download the mathematica file and source images.

3×3 Matrix transform

Monday, November 16th, 2009

A few months ago a friend from FlashMN asked about finding a coordinate transform from one volume (3D space) to another.  Well, here is one of the simplest method, solving for a 3×3 matrix (assuming linear, non-distorted transform on a plane).  This is written in Mathematica 7 notebook.  Reference: Measuring Color 2nd Edition by R. W. Hunt, pg. 204-5.