how to split image to 3 parts
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Image Analyst
2021-12-30
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, :);
8 个评论
Image Analyst
2021-12-31
See attached demo. It will be easy to adapt it to find characters once you have extracted each panel.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/849190/image.png)
更多回答(1 个)
Meg Noah
2022-1-2
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
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/850405/image.jpeg)
by spatial
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/850410/image.jpeg)
2 个评论
Image Analyst
2022-1-2
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
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;
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/850695/image.jpeg)
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/850700/image.jpeg)
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