draw line in a picture

조회 수: 6(최근 30일)
lena kappa
lena kappa 2021년 3월 26일
편집: Walter Roberson 2021년 4월 4일
Hello guys does anyone know how can i draw a line in a picture.
For example i want to draw a 45 degree red line in the next picture starting from the top left corner of the picture and ending n the other end of the picture.

채택된 답변

Walter Roberson
Walter Roberson 2021년 3월 26일
편집: Walter Roberson 2021년 4월 4일
img = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/562881/image.jpeg');
sz = size(img);
endx = min(sz(1), sz(2));
h(1) = image(img);
hold on
h(2) = plot([1 endx], [1 endx], 'r');
hold off
Or if you need the line "burned in" to the image:
img = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/562881/image.jpeg');
sz = size(img);
endx = min(sz(1), sz(2));
nimg = insertShape(img, 'Line', [1 1 endx endx], 'Color', 'r');
h(1) = image(nimg);
The difference between these two is that in the first version, the red line is only visible in what is drawn, with it not being made part of the image array; h will end up as a vector containing the handle to the image display object that only knows about the gray scale image, and a handle to the line display object. In the second version, the red line is part of the array stored in nimg, suitable for further processing (or writing to a file), and h will be the handle of the image display object that only knows about displaying the array that inherently has the red line as part of the data.
  댓글 수: 11
Walter Roberson
Walter Roberson 2021년 4월 4일
I corrected the insertShape call,
nimg = insertShape(nimg, 'Line', [0 0 endx endy], 'Color', line_cols{k});

댓글을 달려면 로그인하십시오.

추가 답변(1개)

MG
MG 2021년 3월 26일
Would this work for you:
hold on
ax=axis;
x = ax(1:2);
y = ax([3 4]); %might want to change cordinates (check with 'axis on')
line(x,y,'Color','red','LineStyle','-')
  댓글 수: 4
lena kappa
lena kappa 2021년 3월 26일
thanks for the answer michael

댓글을 달려면 로그인하십시오.

태그

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by