width to height ratio of various images

I want to find width to height ratio of a rectangle which is made around this person as shown in figure, Rectangle just like start from person's forward fingure and end at backward ankle. I have around 80 images so basically want a looping program that gives me all 80 image's width to height ratio of the corrosponding rectangles.

Answer 1

[KALYAN ACHARJYA]

It seems to be a project related task (not homework), so I have answered it

Supposedly, you have that red markers in the image, if not then also, you can apply the simmiler apprach to get maximum and minimum pixels positions in the segmented image. The challenge is not associated with achieving length and width, the main challenge is to properly divide ROI (Getting ROI's boundary pixels properly), if all other images have the same poor illumination and vice versa, there may be a possibility to fit a certain threshold as I shown below. So I suggest you to focus on ROI segmentation properly, if this is done, the rest is quite easy.

rgbImage=imread('image_preeti.jpeg');
grayImage=rgb2gray(rgbImage);
th=0.05; %Adjust the threshold accordingly
% Or See other robust image segmentation approaches
bwImage=imbinarize(histeq(grayImage),0.05);

You may need to modify the next line as needed.

frame_data=bwareafilt(bwImage & ~bwareafilt(bwImage,1),2);
[r,c]=find(frame_data==1);
diff_c=max(c)-min(c);
diff_r=max(r)-min(r);
figure,imshow(rgbImage);
rectangle('position', [min(c)-diff_c,min(r),2*diff_c,min(r)+diff_r], 'edgecolor', [1 0 0]);

Futher get the length and windth data, use the following (Simple Maths)

w_data=[min(r),max(r)];
l_data=[min(c),max(c)];

You may have to modify the code as per movement of the legs, whether the left or right leg is forward. Please be sure that, if you try it more or other options, you may get more accurate results. Rearding loop, there are many answers available to perform image call and operation one after the other.

Good Wishes!

Kalyan :)

[preeti verma]

Basically i want the distance between toe and ankle which is regularly change, and want a program it should be a loop that can use any problem like this. want values of that distance.

[KALYAN ACHARJYA]

"Basically i want the distance between toe and ankle which is regularly change"

You can do the same also, just clustered the rows values from minimum, mid and maximum of all red markers, consider the mean of mid and maximum case only (For cloumns, min and max columns) and rest part is same.

"want a program it should be a loop that can use any problem like this"

If the task is tested for multiple images (test one by one), then it is quite easy to call images using loop and perform the task one by one. Please search on MATLAB answer (Call Images from Folder)

Srore the distance in an array for 80 images

"want values of that distance"

You can calculate the Euclidian Distance between two pixels (12th Class Maths sqrt(x2-x2)^2-(y2-y1)^2))

If you wish to get the distnace in cm or mm, in that case you may have to calibtarte the factor as per distnace between image sensor and objects. See here

[preeti verma]

frame_data=bwareafilt(bwImage & ~bwareafilt(bwImage,1),2);

What is the mean by this line can you explain ?

[KALYAN ACHARJYA]

@preeti verma I have used that logic to get the desired results

Here

bwareafilt(bwImage,1)
% Return the 1 highest blob (white part) only
%Rest part is self explanatory ~invert image, & or Operation

You can break the line into multiple lines to understand clearly.