how can i find the distance from the peak of one wave to another wave in a image?

i need to find the distance of the wave. i refer to some questions & answers from that i get to know can solve canny's edge detection method.

but i don't know how to process it. can anyone help me...?

[darova]

YOu want to detect the peaks automatically?

[basha Shaik]

yes because i need to solve for 20000 images.

[darova]

Can you attach 3 more?

[basha Shaik]

yaa i attached more images

Answer 1

[darova]

I suggest next algorithm

• imcrop region of interest (since it's always at the same position
• imbinarize image
• maybe clear a bit with bwareaopen
• find pixels you are interested in
• use findpeaks

[basha Shaik]

thank you, can u suggest in brief with code...?

[darova]

I tried to define distance in 00001.jpg image

Can you tell the difference between D1 and D2? Don't how to identify them

00003.jpg image

[basha Shaik]

it is just the wave before the breakup of the liquid sheet. i need to find the wave peak. in that d1 is occurs before the breakup. but d2 is already breakup into liquid droplets.

[darova]

Please upload 10 more pictures for experiments

[basha Shaik]

yaa. i had uploaded more images.

[darova]

I wrote a script

Some explanations:

• Experiment with number of removing pixels

I2 = bwareaopen(I1,2e2);                % remove small objects

• Experiment with reducing of number of points

ii = 1:5:length(x);                     % reduce number of points

• Experiment with peakheight

[~,locs] = findpeaks(abs(kk),'MINPEAKDISTANCE',3,...
                            'MINPEAKHEIGHT', 0.05);

• Experiment with angle of liquid breakup

If angle is small - consider/measure 2d peak

If angle is big - consider/measure 1th peak

if atan2d(dy(end),dx(end)) > 110        % angle of breakup

Feel free to ask question. Let me know if something doesn't work

[darova]

I attach some of my attempts (automatically defined points)

[basha Shaik]

thank you very much. but what the pixel length of that wave distance...? i didn't understand that. and this code can generate for all the images at once....?

[darova]

Sure. See script. I made it like a function

[basha Shaik]

thank you. but i got some error while run the script.

Error using chckxy (line 30)

The first two inputs must have at least two elements.

Error in spline (line 72)

[x,y,sizey,endslopes] = chckxy(x,y);

Error in main>write_length (line 39)

x2 = spline(t1,x1,t2);

Error in main (line 4)

write_length(STR);

[darova]

Show your image. Remove it or replace from folder and change your main code as

function main
for i = 1:3
    STR = sprintf('%05d.jpg',i);
    if exist(STR,'file')
        write_length(STR);
    end
    pause(1)
end 
end

[basha Shaik]

getting the same error, again and again

[darova]

Can you show some of images you get an error?

[basha Shaik]

i run all the 13000 images at once; when i run i got the above error. i shared some of the images here

[darova]

Here is what got

I only commented these lines because of

% set(gca,'clim',[-1 1]/3)
% colormap default

See .zip file

[darova]

In case of other error try this:

function main
for i = 0:1
    try
        STR = sprintf('%05d.jpg',i);
        write_length(STR);
        pause(1)
    catch ME
        if ~exist(STR,'file')
            disp(['File ' STR ' Does not exist'])
        else
            disp(ME.identifier)
            disp(['File ' STR ' was not processed'])
        end
    end
end
end

[darova]

Remember about accepting answer if it helped

Answer 2

[basha Shaik]

sorry for making you trouble and thank you for helping me.

here, i attached the output i got but i didn't understand exactly, here i explain in brief

i need to solve 13000 images at once and need to save the value of wave length in .dat file or any numerical value format.

can u help me with the code for solving this problem.

do u solve the all the images at once....?

[darova]

Try this script. Please attach/show 'data.dat' after processing

[basha Shaik]

thank u very much.

2.jpg

3.jpg 15.9798035376983

4.jpg MATLAB:badsubscript

5.jpg 17.3668315184042

6.jpg

7.jpg 19.6975375353927

8.jpg

9.jpg 34.2065668340247

11.jpg

12.jpg 49.2911737269352

13.jpg 34.8050889623858

this the dat data. but it not showing for some images.

[darova]

Experiment with this line

>> STR = sprintf('%05d.jpg',15)
STR =
00015.jpg
>> STR = sprintf('%05d.jpg',8)
STR =
00008.jpg
>> STR = sprintf('%01d.jpg',8)
STR =
8.jpg

[basha Shaik]

i tried but the output it not detecting 2, 8 ,13. i attached the below output image

[darova]

Please attach original images

[basha Shaik]

here are the original images

[darova]

I changed angle of breakup for 2.jpg

if atan2d(dy(end),dx(end)) > 130        % angle of breakup

Result

I think 11.jpg is defective. I don't see here a wave. Can you see?

8.jpg is problem. I don't how to measure a wave length. Sorry