I have a image
I have created boundary for the necessary part of my image using bwboundaries();
Now i want to remove rest of the image and make it black like :
how will i do this?
MATLAB: How to cut part of an image
image analysisimage processingimage segmentation
Related Solutions
OK, try this. Let me know if it doesn't meet your needs and why.
% Mask a leaf out of an RGB image.
clc; % Clear the command window.
clear all;close all;workspace; % Make sure the workspace panel is showing.
format long g;format compact;fontSize = 24;%===============================================================================
% Read in leaf color demo image.
folder = pwdbaseFileName = 'leaf.jpg';% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);if ~exist(fullFileName, 'file') % Didn't find it there. Check the search path for it.
fullFileName = baseFileName; % No path this time.
if ~exist(fullFileName, 'file') % Still didn't find it. Alert user.
errorMessage = sprintf('Error: %s does not exist.', fullFileName); uiwait(warndlg(errorMessage)); return; endendrgbImage = imread(fullFileName);% Get the dimensions of the image. numberOfColorBands should be = 3.
[rows, columns, numberOfColorChannels] = size(rgbImage);% Display the original color image.
subplot(2, 2, 1);imshow(rgbImage);title('Original Color Image', 'FontSize', fontSize, 'Interpreter', 'None');% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'Outerposition', [0, 0, 1, 1]);% Extract the individual red, green, and blue color channels.
% redChannel = rgbImage(:, :, 1);
% greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);% Create a mask of the background only.
mask = blueChannel > 200;% Display the mask image.
subplot(2, 2, 2);imshow(mask);title('Mask Image', 'FontSize', fontSize, 'Interpreter', 'None');% Mask out the leaf, leaving only the background.
% Mask the image using bsxfun() function
maskedRgbImage = bsxfun(@times, rgbImage, cast(mask, 'like', rgbImage));% Display the mask image.subplot(2, 2, 3);imshow(maskedRgbImage);title('Background-Only Image', 'FontSize', fontSize, 'Interpreter', 'None');% Mask out the background, leaving only the leaf.
% Mask the image using bsxfun() functionmaskedRgbImage = bsxfun(@times, rgbImage, cast(~mask, 'like', rgbImage));% Display the mask image.subplot(2, 2, 4);imshow(maskedRgbImage);title('Leaf-Only Image', 'FontSize', fontSize, 'Interpreter', 'None');
Try this:
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
imtool close all; % Close all imtool figures if you have the Image Processing Toolbox.
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;format compact;fontSize = 20;% Check that user has the Image Processing Toolbox installed.
hasIPT = license('test', 'image_toolbox');if ~hasIPT % User does not have the toolbox installed.
message = sprintf('Sorry, but you do not seem to have the Image Processing Toolbox.\nDo you want to try to continue anyway?'); reply = questdlg(message, 'Toolbox missing', 'Yes', 'No', 'Yes'); if strcmpi(reply, 'No') % User said No, so exit.
return; endend% Read in gray scale demo image.
folder = 'C:\Users\jhilam\Documents\Temporary';baseFileName = 'CT14.jpg';% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);% Check if file exists.
if ~exist(fullFileName, 'file') % File doesn't exist -- didn't find it there. Check the search path for it.
fullFileName = baseFileName; % No path this time.
if ~exist(fullFileName, 'file') % Still didn't find it. Alert user.
errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName); uiwait(warndlg(errorMessage)); return; endendgrayImage = imread(fullFileName);% Get the dimensions of the image.
% numberOfColorBands should be = 1.
[rows, columns, numberOfColorBands] = size(grayImage);if numberOfColorBands > 1 % It's not really gray scale like we expected - it's color.
% Convert it to gray scale by taking only the green channel.
grayImage = grayImage(:, :, 2); % Take green channel.
end% Display the original gray scale image.
subplot(2, 3, 1);imshow(grayImage, []);title('Original Grayscale Image', 'FontSize', fontSize);% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off') % Blacken the white bar artifact in the left 5 columns.
grayImage(:, 1:5) = 0;% Let's compute and display the histogram.
[pixelCount, grayLevels] = imhist(grayImage);subplot(2, 3, 2); bar(grayLevels, pixelCount);grid on;title('Histogram of original image', 'FontSize', fontSize);xlim([0 grayLevels(end)]); % Scale x axis manually.
% Binarize the image to get the body.
binaryImage = grayImage > 150;% Display the binary image.
subplot(2, 3, 3);imshow(binaryImage, []);title('Binary Image', 'FontSize', fontSize);% Fill and get rid of small objects
binaryImage2 = imfill(binaryImage, 'holes');minAcceptableSize = round(rows*columns*0.05);binaryImage2 = bwareaopen(binaryImage2, minAcceptableSize);% Display the binary image.subplot(2, 3, 4);imshow(binaryImage2, []);title('Binary Image 2', 'FontSize', fontSize);% Invert and OR
binaryImage2 = ~(~binaryImage2 | binaryImage);% Display the binary image.subplot(2, 3, 5);imshow(binaryImage2, []);axis on;title('Binary Image 2', 'FontSize', fontSize);% Fill again
binaryImage3 = imfill(binaryImage2, 'holes');% Get rid of small things again.
binaryImage3 = bwareaopen(binaryImage3, minAcceptableSize);% And it with binary image 2
binaryImage3 = binaryImage3 & binaryImage2;% Display the binary image.subplot(2, 3, 6);imshow(binaryImage3, []);title('Binary Image 3', 'FontSize', fontSize);uiwait(helpdlg('Done with Demo by Image Analyst!'));
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