Grayscale Slicing

Where you define function f of x and choose levels "a" and "b"

Description

Define a function f of x and choose levels "a" and "b" such that f(x)={xmax when "a" is less than or equal to "x" less than or equal to "b" and 0 otherwise, will perform grayscale slicing.

• Required Products: Image Processing Toolbox
• MATLAB release: MATLAB 7.2 (R2006a)

[Matthew Whitaker]

1) No error checking
2) Assumes an RGB input
3) Loop is totally unnecessary
The function would be more useful written something like:
function slicing(filename,a,b) % function definition
%SLICING produces a BW map of an slice of a grayscale image
% Grey scale slicing
% slicing(filename,a,b)
% f(x)= true for a<=x<=b
% = false otherwise
if b <= a
    error('Invalid Input: b <= a')
end %if

[sir,map] = imread(filename); % reading the image
              
if ndims(sir) < 3;
    if isempty(map)
        ir = sir;
    else
        ir = ind2gray(sir,map);
    end %if
else
    ir = rgb2gray(sir);
end %if

nir = false(size(ir));
nir(ir >= a & ir <= b) = true;

subplot(1,2,1),imshow(ir);
hold on;
subplot(1,2,2),imshow(nir);

[Stephen Silvis]

I thought it was good