TableInterp2d

Overview

Table driven 2d interpolation module. Currently supports only bilinear interpolation

Discussion

This module performs an interpolated 2-dimensional table lookup using a grid of values evenly spaced from -1 to 1. The module currently supports only bilinear interpolation. The input pins specify the X and Y values at which to perform the interpolation. 4 points in the table are used and bilinear interpolation is applied. The X values interpolate along a row and Y values interpolate along a column.

The range of X and Y are always [-1 +1]. Values outside of this range are clipped to +/- 1.

At instantiation, specify the total number of points (NPOINTS) in each dimension of the table. The amount of memory allocated to the table equals (NPOINTS * NPOINTS).

Module Pack

Advanced

ClassID

classID = 1341

Type Definition

typedef struct _ModuleTableInterp2d
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
INT32 nPoints;                                // Number of points in each dimension of the active interpolation table.
FLOAT32* table;                               // 2d Interpolation Lookup table
} ModuleTableInterp2dClass;

Variables

Properties

Name	Type	Usage	isHidden	Default Value	Range	Units
nPoints	int	const	0	5	Unrestricted
table	float*	parameter	0	[5 x 5]	Unrestricted

Pins

Input Pins


Name	inx
Description	index x
Data type	float
Channel range	Unrestricted
Block size range	Unrestricted
Sample rate range	Unrestricted
Complex support	Real


Name	iny
Description	index y
Data type	float
Channel range	Unrestricted
Block size range	Unrestricted
Sample rate range	Unrestricted
Complex support	Real

Output Pins


Name	out
Description	audio output
Data Type	float

Matlab Usage

File Name: table_interp2d_module.m 
 M=table_interp2d_module(NAME, NPOINTS) 
 This Audio Weaver process performs bilinear interpolation between values 
 defined on a lattice with NPTS evenly spaced points from [-1,1] in x and 
 y.  For input coordinates between the lattice points, interpolate 
 linearly for x and then for y. 

 Arguments: 
    NAME - name of the module. 
    NPOINTS - number of points in each dimension. This is set at design 
       time and has a minimum value of 2. 

 The internal variable .table holds the underlying table of values. 
 .table has a size of NPOINTS x NPOINTS.