how to split image to 3 parts

Question

amr elslene 2021-12-30

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1619960-how-to-split-image-to-3-parts

评论： Meg Noah 2022-1-2

采纳的回答： Image Analyst

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Answer 1

Image Analyst 2021-12-30

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1619960-how-to-split-image-to-3-parts#answer_865410

在 MATLAB Online 中打开

Like top third, left bottom panel, and right bottom panel? Is the image the same size every time so that all dividing rows and column can be determined in advance?

[rows, columns, numberOfColorChannels] = size(rgbImage);
row1 = round(rows/3);
col1 = round(columns/2);
topThird = rgbImage(1 : row1, :, :);
leftPanel = rgbImage(row1 + 1 : end, 1 : col1, :);
rightPanel = rgbImage(row1 + 1 : end, col1 + 1 : end, :);

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Image Analyst 2021-12-31

在 MATLAB Online 中打开

image.jpeg

There are better ways but first you need to answer my questions.

Like what are the three regions?
Are the images all the same size?
Are the regions at the same rows and columns in all your images?

Here is a more sophisticated region extraction:

% Demo by Image Analyst.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clearvars;
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 16;
fprintf('Beginning to run %s.m ...\n', mfilename);
%-----------------------------------------------------------------------------------------------------------------------------------
% Read in image.
folder = [];
baseFileName = 'image.jpeg';
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
    % The file doesn't exist -- didn't find it there in that folder.
    % Check the entire search path (other folders) for the file by stripping off the folder.
    fullFileNameOnSearchPath = baseFileName; % No path this time.
    if ~exist(fullFileNameOnSearchPath, '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;
    end
end
rgbImage = imread(fullFileName);
[rows, columns, numberOfColorChannels] = size(rgbImage)
% Display the image.
subplot(3, 2, 1);
imshow(rgbImage, []);
axis('on', 'image');
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
caption = sprintf('Original RGB Image : "%s"\n%d rows by %d columns', baseFileName, rows, columns);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
% Set up figure properties:
% Enlarge figure to full screen.
hFig1 = gcf;
hFig1.Units = 'Normalized';
hFig1.WindowState = 'maximized';
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
hFig1.Name = 'Demo by Image Analyst';
%-----------------------------------------------------------------------------------------------------------------------------------
% Split into 3 color channels.
[redChannel, greenChannel, blueChannel] = imsplit(rgbImage);
% Get the blue mask.
threshold = 130;
blueMask = blueChannel > threshold & greenChannel < threshold;
% Take largest one.
blueMask = bwareafilt(blueMask, 1);
% Display the image.
subplot(3, 2, 2);
imshow(blueMask, []);
axis('on', 'image');
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
title('Blue Mask Image', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
% Get white mask
whiteMask = blueChannel > 250 & greenChannel > 250;
% Get rid of border.
whiteMask = imclearborder(whiteMask);
% Take 2 largeset blobs.
whiteMask = bwareafilt(whiteMask, 2);
% Display final mask
subplot(3, 2, 3);
imshow(whiteMask, []);
axis('on', 'image');
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
title('White Mask', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
% Find the bounding boxes.
blueProps = regionprops(blueMask, 'BoundingBox');
whiteProps = regionprops(whiteMask, 'BoundingBox');
% Crop out blue region
blueRegion = imcrop(rgbImage, blueProps.BoundingBox);
whiteRegion1 = imcrop(rgbImage, whiteProps(1).BoundingBox);
whiteRegion2 = imcrop(rgbImage, whiteProps(2).BoundingBox);
%-----------------------------------------------------------------------
% Display the cropped regions.
subplot(3, 2, 4);
imshow(blueRegion, []);
axis('on', 'image');
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
title('Blue Region', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
subplot(3, 2, 5);
imshow(whiteRegion1, []);
axis('on', 'image');
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
title('White Region 1', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
subplot(3, 2, 6);
imshow(whiteRegion2, []);
axis('on', 'image');
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
title('White Region 2', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;

amr elslene 2021-12-31

编辑：amr elslene 2021-12-31

all i need is take like that

from plat like that

Thanks in advance @Image Analyst

Image Analyst 2021-12-31

@amr elslene, well it would have been nice to know that before.

See attached demo. It will be easy to adapt it to find characters once you have extracted each panel.

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Answer 2

Meg Noah 2022-1-2

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1619960-how-to-split-image-to-3-parts#answer_866435

在 MATLAB Online 中打开

Here are two ways:

close all
clear
clc
[imdata,~] = imread('image.jpeg');
% split into three color channels of equal size
imRed = squeeze(imdata(:,:,1));
imGreen = squeeze(imdata(:,:,2));
imBlue = squeeze(imdata(:,:,3));
figure()
subplot(2,2,1)
imagesc(imRed)
axis off; axis equal;
colormap(gca,'gray')
title('Red')
subplot(2,2,2)
imagesc(imGreen)
axis off; axis equal;
colormap(gca,'gray')
title('Green')
subplot(2,2,3)
imagesc(imBlue)
axis off; axis equal;
colormap(gca,'gray')
title('Blue')
subplot(2,2,4)
imagesc(imdata)
axis off; axis equal;
title('Color Composite')
% spatial 
[nrow,ncol] = size(imGreen);
[Cols,Rows] = meshgrid(1:ncol,1:nrow);
lowerRegion = imGreen;
lowerRegion(lowerRegion < 200) = 0;
lowerRegion(lowerRegion > 0) = 1;
L = bwlabel(lowerRegion);
% can logically evaluate a histcounts of L to determine thresholds
lowerLCol1 = min(Cols(L == 2));
lowerLCol2 = max(Cols(L == 2));
lowerLRow1 = min(Rows(L == 2));
lowerLRow2 = max(Rows(L == 2));
imLowerL = imdata(lowerLRow1:lowerLRow2,lowerLCol1:lowerLCol2,:);
lowerRCol1 = min(Cols(L == 4));
lowerRCol2 = max(Cols(L == 4));
lowerRRow1 = min(Rows(L == 4));
lowerRRow2 = max(Rows(L == 4));
imLowerR = imdata(lowerRRow1:lowerRRow2,lowerRCol1:lowerRCol2,:);
topRegion = 1 - lowerRegion;
topRegion = imopen(topRegion,ones(7,1));
topRegion = imopen(topRegion,ones(1,7));
topCol1 = min(Cols(topRegion > 0));
topCol2 = max(Cols(topRegion > 0));
topRow1 = min(Rows(topRegion == 1));
topRow2 = max(Rows(topRegion == 1));
imTop = imdata(topRow1:topRow2,topCol1:topCol2,:);
figure()
subplot(2,2,1);
imagesc(imTop);
axis off; axis equal;
title('Top Image');
subplot(2,2,2);
imagesc(imLowerL);
axis off; axis equal;
title('Lower Left Image');
subplot(2,2,3);
imagesc(imLowerR);
axis off; axis equal;
title('Lower Right Image');
subplot(2,2,4);
imagesc(L);
axis off; axis equal;
title('Color Coded Regions');

by color component

by spatial

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Image Analyst 2022-1-2

在 MATLAB Online 中打开

His later comments were that what he really wanted was to split the lower panels into individual characters. You can do this by taking the horizontal profile:

horizontalProfile = sum(mask, 1);

and then thresholding that to find columns that have some black in them or are all white.

Meg Noah 2022-1-2

在 MATLAB Online 中打开

Continuing with the previous script:

% getting the text
tmp = imGreen(lowerLRow1:lowerLRow2,lowerLCol1:lowerLCol2,:);
tmp(tmp < 190) = 0;
tmp(tmp > 0) = 1;
% invert
tmp = 1 - tmp;
% remove border artifacts
tmp(1,:) = 0;
tmp(:,1) = 0;
tmp(end,:) = 0;
tmp(:,end) = 0;
% close to get full font
tmp = imclose(tmp,ones(5,5));
% blob color
LL = bwlabel(tmp);
[nr,nc] = size(LL);
[Cols,Rows] = meshgrid(1:nc,1:nr);
LLCol1 = min(Cols(LL == 1));
LLCol2 = max(Cols(LL == 1));
LLRow1 = min(Rows(LL == 1));
LLRow2 = max(Rows(LL == 1));
imFont1 = imLowerL(LLRow1:LLRow2,LLCol1:LLCol2,:);
LLCol1 = min(Cols(LL == 2));
LLCol2 = max(Cols(LL == 2));
LLRow1 = min(Rows(LL == 2));
LLRow2 = max(Rows(LL == 2));
imFont2 = imLowerL(LLRow1:LLRow2,LLCol1:LLCol2,:);
LLCol1 = min(Cols(LL == 3));
LLCol2 = max(Cols(LL == 3));
LLRow1 = min(Rows(LL == 3));
LLRow2 = max(Rows(LL == 3));
imFont3 = imLowerL(LLRow1:LLRow2,LLCol1:LLCol2,:);
figure()
subplot(2,2,1)
imagesc(LL);
axis off; axis equal;
subplot(2,2,2)
imagesc(imFont1);
axis off; axis equal;
subplot(2,2,3)
imagesc(imFont2);
axis off; axis equal;
subplot(2,2,4)
imagesc(imFont3);
axis off; axis equal;
tmp = imGreen(lowerRRow1:lowerRRow2,lowerRCol1:lowerRCol2,:);
tmp(tmp < 190) = 0;
tmp(tmp > 0) = 1;
% invert
tmp = 1 - tmp;
% remove border artifacts
tmp(1,:) = 0;
tmp(:,1) = 0;
tmp(end,:) = 0;
tmp(:,end) = 0;
% close to get full font
tmp = imclose(tmp,ones(5,5));
% blob color
LR = bwlabel(tmp);
[nr,nc] = size(LR);
[Cols,Rows] = meshgrid(1:nc,1:nr);
LRCol1 = min(Cols(LR == 1));
LRCol2 = max(Cols(LR == 1));
LRRow1 = min(Rows(LR == 1));
LRRow2 = max(Rows(LR == 1));
imFont1 = imLowerR(LRRow1:LRRow2,LRCol1:LRCol2,:);
LRCol1 = min(Cols(LR == 2));
LRCol2 = max(Cols(LR == 2));
LRRow1 = min(Rows(LR == 2));
LRRow2 = max(Rows(LR == 2));
imFont2 = imLowerR(LRRow1:LRRow2,LRCol1:LRCol2,:);
LRCol1 = min(Cols(LR == 3));
LRCol2 = max(Cols(LR == 3));
LRRow1 = min(Rows(LR == 3));
LRRow2 = max(Rows(LR == 3));
imFont3 = imLowerR(LRRow1:LRRow2,LRCol1:LRCol2,:);
figure()
subplot(2,2,1)
imagesc(LR);
axis off; axis equal;
subplot(2,2,2)
imagesc(imFont1);
axis off; axis equal;
subplot(2,2,3)
imagesc(imFont2);
axis off; axis equal;
subplot(2,2,4)
imagesc(imFont3);
axis off; axis equal;