How to combine: image - optical flow - coordinate system (axis2pixels)

Question

Paul Matteschk 2022-1-22

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1633740-how-to-combine-image-optical-flow-coordinate-system-axis2pixels

编辑： Aishwarya 2023-10-6

在 MATLAB Online 中打开

hi everyone,

my goal is to calculate windspeed from cloudimages (frames).

I use Lucas Kanade for Flow Estimation.

Unfortunalty iam stucked by plotting my results:

-i want the output diagramm/image/flowfield full frame without white border

-moreover i would like to add axis with the pixel units (tried imref2d)

-and a grid

I am sure there is a way. but who knows him?

% display optical flow
step = 30;
imshow(im_2);
[w,h] = size(optical_flow_u);
u_down = optical_flow_u(1:step:end, 1:step:end);
v_down = optical_flow_v(1:step:end, 1:step:end);
[m,n] = size(im2_level);
[X,Y] = meshgrid(1:n, 1:m);
X_down = X(1:step:end, 1:step:end);
Y_down = Y(1:step:end, 1:step:end);
hold on;
quiver(X_down, Y_down, u_down, v_down, 0.5, 'color',[1 0 0]);

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Aishwarya 2023-10-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1633740-how-to-combine-image-optical-flow-coordinate-system-axis2pixels#answer_1327619

编辑：Aishwarya 2023-10-6

在 MATLAB Online 中打开

Hi Paul,

As per my understanding you are facing difficulties in changing the plot properties of the flow estimation output.

To address your questions.

Change the property of the figure:

Change “Position” property of the figure window according to image size and position of figure required.

        f = figure;  
        f.Position = [10 10 500 500]; 

To add axis and grid to the plot:

“axis on” will add the axis in pixel units. Consider making the following changes in the code:

        hold on;
        quiver(X_down, Y_down, u_down, v_down, 0.5, 'color',[1 0 0]); 
        
        % Add axis and label them 
        axis on; 
        xlabel('X (pixels)'); 
        ylabel('Y (pixels)'); 
        
        % Turn on grid 
        grid on; 
        hold off; 
        