How to change the pixel values without using for-loop ?

let i have a image matrix like : A =

   120   200   250   254   225
   204   235   226   227     1
   243   249   225    29     1
    27    82    92   222   224
    12   252   229   255   255

I want to change the values within range 240 to 255 into 0 without using for-loop The output array or matrix will be : A =

   120   200   0     0     225
   204   235   226   227     1
     0    0     225   29     1
    27    82    92   222   224
    12     0   229   0      0

how will I calculate it ?

[Stephen23]

Such basic MATLAB usage is taught in these tutorials:

http://www.mathworks.com/help/matlab/getting-started-with-matlab.html

And certainly it is covered by "Logical Indexing – Example 1" here:

http://www.mathworks.com/help/matlab/math/matrix-indexing.html

Answer 1

[Guillaume]

This is a basic matrix operation that I'm sure is covered in Getting started:

A(A >= 240) = 0

[Priyanka Roy]

Thanks :)

[Richard Hall]

That "basic matric operation" is not in "Getting Started".