NSCT Toolbox (MATLAB) - Nonsubsampled Contourlet Transform Implementation

This content describes the nonsubsampled contourlet transform (NSCT) method implemented in MATLAB. The original implementation was developed and tested for 32-bit MATLAB environments, and users may encounter runtime errors when attempting to execute it on 64-bit MATLAB versions. To ensure proper functionality, the installation requires compiling three C source files using MATLAB's mex compiler. The compilation process and specific instructions are documented within the compressed package. The NSCT algorithm provides superior image representation through a flexible multi-scale and directional decomposition framework. Key implementation components include directional filter banks for capturing directional information and pyramid structures for multi-scale analysis. The transform maintains translation invariance by eliminating downsampling operations, making it particularly suitable for image processing applications requiring shift-invariant properties. To address the 64-bit compatibility issue, users may need to modify the mex compilation commands to target their specific MATLAB architecture. The toolbox's core functionality involves implementing the NSCT decomposition and reconstruction processes through carefully designed filter banks and multi-resolution analysis techniques.