# How to change Y-axis coordinates of meshgrid

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Med Future on 20 Mar 2022
Answered: Image Analyst on 22 Mar 2022
Hello Everyone, i hope you are doing well. I am creating binary Image in which background is black and forground is white
when i create grid of 1000x1000. The X-axis start from 0 to 1000 but Y axis is upper side 0 to 1000 as you can see in the following image , but i want Y axis to be start from Lower 0 to 1000
How can i do that in MATLAB
imSz = 1000; % assuming images are 1000x1000
imbg = false(imSz); % background "color"
imfg = ~imbg(1,1);
[~,Y] = meshgrid(1:imSz); % make a grid
% black and white image
BW = imbg;
imshow(BW)
axis on;

Image Analyst on 22 Mar 2022
That's the convention for matrixes and images - the y=1 value is at the top. If you want to reverse it use "axis xy" like
[rows, columns, numberOfColorChannels] = size(grayImage);
subplot(2, 1, 1);
imshow(grayImage);
axis('on', 'xy');
subplot(2, 1, 2);
imshow(flipud(grayImage));
axis('on', 'xy');

KSSV on 20 Mar 2022
>> hax = gca;
hax.YTickLabel = flipud(hax.YTickLabel);
##### 3 CommentsShow 1 older commentHide 1 older comment
KSSV on 20 Mar 2022
[~,Y] = meshgrid(imSz:-1:1); % make a grid
Med Future on 20 Mar 2022
@KSSV Still not working. same result as above

yanqi liu on 21 Mar 2022
imSz = 1000; % assuming images are 1000x1000
imbg = false(imSz); % background "color"
imfg = ~imbg(1,1);
[~,Y] = meshgrid(1:imSz); % make a grid
% black and white image
BW = imbg;
imshow(BW)
axis on;
axis xy
Med Future on 21 Mar 2022
@yanqi liu What changes you have made?
yanqi liu on 22 Mar 2022
yes，sir，use axis xy to make the coordinate as norma xy axis， not use image axis

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