Description of sopt_mltb_gradient_op
Description: sopt_mltb_gradient_op - Compute gradient

Home > matlab > misc > sopt_mltb_gradient_op.m

# sopt_mltb_gradient_op

## PURPOSE

sopt_mltb_gradient_op - Compute gradient

## SYNOPSIS

function [dx, dy] = sopt_mltb_gradient_op(I, weights_dx, weights_dy)

## DESCRIPTION

     sopt_mltb_gradient_op - Compute gradient

     Compute the gradient of a two dimensional signal.

     Inputs:

       - I: Input two dimesional signal.

       - weights_dx: Weights in the x direction.

       - weights_dy: Weights in the y direction.

     Outputs:

       - dx: Gradient in x direction.

       - dy: Gradient in y direction.

## CROSS-REFERENCE INFORMATION

This function calls:

This function is called by:

- sopt_mltb_TV_norm sopt_mltb_TV_norm - Compute TV norm

## SOURCE CODE

    0001 function [dx, dy] = sopt_mltb_gradient_op(I, weights_dx, weights_dy)
    0002 % sopt_mltb_gradient_op - Compute gradient
    0003 %
    0004 % Compute the gradient of a two dimensional signal.
    0005 %
    0006 % Inputs:
    0007 %
    0008 %   - I: Input two dimesional signal.
    0009 %
    0010 %   - weights_dx: Weights in the x direction.
    0011 %
    0012 %   - weights_dy: Weights in the y direction.
    0013 %
    0014 % Outputs:
    0015 %
    0016 %   - dx: Gradient in x direction.
    0017 %
    0018 %   - dy: Gradient in y direction.
    0019
    0020 dx = [I(2:end, :)-I(1:end-1, :) ; zeros(1, size(I, 2))];
    0021 dy = [I(:, 2:end)-I(:, 1:end-1) , zeros(size(I, 1), 1)];
    0022
    0023 if nargin>1
    0024     dx = dx .* weights_dx;
    0025     dy = dy .* weights_dy;
    0026 end
    0027
    0028 end