Adding line change the size of the image

Hi!

I am currently working on adding lines above a image in App Designer, but when I add these lines, the image changes size and I don't want it to. Can someone help me please?

M is a 4D matrix(160,130,26,14)

profondeur, hauteur, largeur, temps are sliders, and angle 1,5 are knob

I=M(:,:,floor(profondeur),floor(temps));

affichagelignex(app);

J=imresize(I,[160 130]);

imshow(J,[],'Parent',app.UIAxes);

function affichagelignex(app)

profondeur = app.zaxegauchedroiteSlider.Value;

hauteur = app.yaxeavantarrireSlider.Value;

largeur = app.xaxepiedstteSlider.Value;

angle1 = app.AngleXYKnob.Value;

angle5 = app.AngleXZKnob.Value;

persistent h1

persistent h5

if (isempty(h1)&& isempty(h5))

h1=line(app.UIAxes,[0 130],[largeur largeur],'Color','green');

h5=line(app.UIAxes3,[0 26],[largeur largeur],'Color','green');

else

h1=line(app.UIAxes,[0 130],[largeur-hauteur*tand(angle1) largeur+(130-hauteur)*tand(angle1)],'Color','green');

h5=line(app.UIAxes3,[0 26],[largeur-profondeur*tand(angle5) largeur+(26-profondeur)*tand(angle5)],'Color','green');

end

Answer 1

[Chad Greene]

Can you get the axis limits before plotting the lines, and then set the axis back to those limits afterwards? Something like this:

ax = axis; % GET THE AXIS LIMITS
if (isempty(h1)&& isempty(h5))
    h1=line(app.UIAxes,[0 130],[largeur largeur],'Color','green');
    h5=line(app.UIAxes3,[0 26],[largeur largeur],'Color','green');
else
    h1=line(app.UIAxes,[0 130],[largeur-hauteur*tand(angle1) largeur+(130-hauteur)*tand(angle1)],'Color','green');
    h5=line(app.UIAxes3,[0 26],[largeur-profondeur*tand(angle5) largeur+(26-profondeur)*tand(angle5)],'Color','green');
end
axis(ax) % SET THE AXIS LIMITS

[Aurélie B]

Thank you for repling

I tried what you sent, but the matrix is still becoming smaller once i changed the sliders or knob of the app and i don't know why

[Chad Greene]

Can you provide before- and after- images to show what you mean when you say the image or the matrix gets smaller?

[Aurélie B]

This is before adding the lines and after.

When I add the lines before changing the sliders, it is okay, but when I do a rotation of the lines, the image becomes really small

[Aurélie B]

Moreover, if you know how to clear the 'old lines' that you can see behind the image, i'd take it too. I tried clear affichagelignex but it didn't work

[Chad Greene]

For the size of the image, I wonder if the position of the axes is being changed when the new lines are plotted. Try this:

axh = gca; % get current axis handle
axpos = get(axh,'position'); % get the current position of the axes 
if (isempty(h1)&& isempty(h5))
    h1=line(app.UIAxes,[0 130],[largeur largeur],'Color','green');
    h5=line(app.UIAxes3,[0 26],[largeur largeur],'Color','green');
else
    h1=line(app.UIAxes,[0 130],[largeur-hauteur*tand(angle1) largeur+(130-hauteur)*tand(angle1)],'Color','green');
    h5=line(app.UIAxes3,[0 26],[largeur-profondeur*tand(angle5) largeur+(26-profondeur)*tand(angle5)],'Color','green');
end
set(axh,'position',axpos) % sets the position of the axis back 

Regarding deleting the old lines, you might need to return the handles of the line objects from the function like this:

[h1,h5] = function affichagelignex(app)

and then try deleting those line objects before calling affichagelignex, like this:

try
    delete(h1)
    delete(h5) 
end

[Aurélie B]

Regarding deleting the old lines, it works, thank you very much!

Unfortunately, regarding the size of the image, it still doesn't work.. I think that the lines still have the good dimensions but the image reduces

[Chad Greene]

Is the viewing angle changing when new lines are plotted? Maybe try the same idea, but get the viewing angle before plotting the lines and set it afterward:

[az,el]= view; 

and then

view(az,el)

[Aurélie B]

Still not working :'( I tried to 'analyse' the problem : when the ends of the line are not on the left and right of the image but on top and bottom, the image is reduced and seems to be moving. Else, there is no problem

[Chad Greene]

Good heavens. I'm sorry, we've reached the end of my ideas for troubleshooting. Hopefully someone with app designing experience can chime in with better ideas. Good luck!

[Aurélie B]

Thank you so much for helping me :)