MATLAB: Remove the unwanted region from an image and rotate it to 45 degree

Image Processing Toolboxremove unwanted portion

I have an image attached with this question. I wanted to remove the unwanted white portion and rotate image to 45 degree angle. The unwanted portion contains values either 255 or 0. Please help me.

Best Answer

Try this:

grayImage = imread('11.bmp');
subplot(2, 2, 1);
imshow(grayImage)
title('Original Image', 'FontSize', 15);
grayImage = imrotate(grayImage, -45);
subplot(2, 2, 2);
imshow(grayImage)
title('Rotated Image', 'FontSize', 15);
% Get mask
mask = bwconvhull(grayImage ~= 255 & grayImage ~= 0);
subplot(2, 2, 3);
imshow(mask)
title('mask', 'FontSize', 15);
% Find cropping index
[rows, columns] = find(mask)
% Crop 
croppedImage = grayImage(min(rows):max(rows), min(columns):max(columns));
subplot(2, 2, 4);
imshow(croppedImage)
title('Cropped Image', 'FontSize', 15);

Related Solutions

MATLAB: Masking some desired portion of an image

It definitely DOES work, but you need to make your mask in the range 0-1. Here's proof:

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clearvars;
workspace;  % Make sure the workspace panel is showing.
fontSize = 20;
format compact;
% Read in a standard MATLAB color demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');
baseFileName = 'peppers.png';
fullFileName = fullfile(folder, baseFileName);
% 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;
  end
end
rgbImage = imread(fullFileName);
% Get the dimensions of the image.  numberOfColorBands should be = 3.
[rows columns numberOfColorBands] = size(rgbImage);
% Display the original color image.
subplot(2, 2, 1);
imshow(rgbImage, []);
title('Original Color Image', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]); % Maximize figure.
mask = zeros(rows, columns, 'uint8');
mask(30:300, 50:150) = 1;
% Normalize to 0 - 1.
mask = mask / 255;
% Display the mask.

subplot(2, 2, 2);
imshow(mask, []);
title('Mask', 'FontSize', fontSize);
maskedRgbImage = bsxfun(@times, rgbImage, cast(mask,class(rgbImage)));
% Display the mask.
subplot(2, 2, 3);
imshow(maskedRgbImage, []);
title('MaskedImage', 'FontSize', fontSize);

MATLAB: How to get gray color

Try using gray levels instead of the 0-1 range. (It's inconsistent, I know)

grayImage = imread('cameraman.tif');
subplot(2, 2, 1);
imshow(grayImage);
title('Original Image', 'fontSize', fontSize);
drawnow;
grayImg = insertShape(grayImage, 'line', [270 20 30 200], ...
  'LineWidth', 10, 'Color', [0.75 0.75 0.75]*255 ); 
subplot(2, 2, 2);
imshow(grayImg);
impixelinfo;

Best Answer

Related Solutions

MATLAB: Masking some desired portion of an image

MATLAB: How to get gray color

Related Question