How to logical AND gray scale image with a constant?

ANDing an 8-bit gray level image with a constant value of 240 (11110000 in binary)?

Answer 1

[Image Analyst]

Use bitand():

n1 = uint8(170); % Some number
n2 = uint8(240);
% Show what they are
dec2bin(n1)
dec2bin(n2)
% And them
out = bitand(n1, n2)
% Show result
dec2bin(out)

ans =
10101010
ans =
11110000
out =
  160
ans =
10100000

It works for images as well as individual numbers.

[Jes]

Thank you very much. Could you please tell me What could be the effect of anding 240 with grayscale image? clc; clear all; close all; I=imread('cameraman.tif'); n1 = uint8(I); % Some number n2 = uint8(240); figure;imshow(I); out = bitand(n1, n2); figure; imshow(out);