How can I find maximums in the intensity profile and display it in the original image ?

I have ('liftingbody.png') image and I want to display the intensity profile along a white curve ('sss.png').

I searched the coordinates of the white curve and I displayed the intensity profile of the ('liftingbody.png') along those coordinates.

After that, I searched the maximums in the c profile and I displayed it in the fused image.

My problem is why I got points outside the red curve ? here is my code.

Could anyone help me solving this problem ?

clear all, close all; clc

I2 = imread('liftingbody.png');
figure
imshow(I2);

I=imread('sss.png');
figure
imshow(I);

[x2,y2]=find (I>0);  % find the coordinates of white line
[cx,cy,c]=improfile(I2, x2,y2);  % display the intensity profile.(cx,xy):coordinates of intensity profile
% [pks,locs] = findpeaks(c);

[pks,locs] = findpeaks(c,'MinPeakDistance',50); % search maximums
figure
plot(c)

% display the curve in red
I = uint8(I);
[x,y,z]=size(I);
 for i=1:x
     for j=1:y
         if (I(i,j)==1)
             I(i,j,1)=255;
             I(i,j,2)=0;
             I(i,j,3)=0;
         end
     end
 end
figure
imshow(I);
title('red curve');

I  = imfuse(I, I2,'blend','Scaling','joint');
figure
imshow(I);
hold on
plot(cy(locs(:)),cx(locs(:)),'b*')

[darova]

Where is liftingbody.png

[KALYAN ACHARJYA]

How can I find maximums in the intensity profile and display it in the original image ?

You have to find the max intensity on the image ('liftingbody.png'), yes?

What is the role of ssss image?

[MMSAAH]

I want to find the max in the intensity profile and display it in the original image.

sss.png image provide as the x2,y2 coordinates on which the intensity profile could be dispayed.

Here attached you could fing the liftingbody.png image

[darova]

Works ok for me

[MMSAAH]

thank you for your answer but if you zoom in the picture even more, you will see many points outside the red curve.

Answer 1

[darova]

I think the problem is in order of points. MAthworks help:

improfile

Pixel-value cross-sections along line segments

Try this

I=imread('sss.png');
[x2,y2] = find (I>0);  % find the coordinates of white line
figure
imshow(I);
hold on
for i = 1:10:length(x2)
    plot(y2(i),x2(i),'.r')
    pause(0.1)
end
hold off

And now add this before plot()

[x2 ,ix] = sort(x2);   % sort vertically
y2 = y2(ix);

So i divided white line into two parts. Sorted top part vertically and bottom part horizontally

See attached script

[MMSAAH]

Thank you very much. This did solve my problem. I'm really grateful.

The problem was in fact related to the order of points

Could you explain me more please ? How did the sort () command solve the problem ?

Thanks a lot.

[darova]

Imagine you have six pixels. You want to find (rows,columns) (position) of them

So order of pixels would be as i marked on the picture

Arrows indicate direction of search

So when you have some curve (marked black) and points (red) you have to find improfile

Blue lines will be the actual path of profile

Answer 2

[KALYAN ACHARJYA]

My problem is why I got points outside the red curve ? here is my code?

scatter(cy(locs(:)),cx(locs(:)),'b')

I dot think there are any points positioning the outside the Marker line (white line turned red line), use other plot way and see the results.

[MMSAAH]

thank you for your answer but if you zoom in the picture even more, you will see many points outside the red curve even when changing plot by scatter

[KALYAN ACHARJYA]

May be there are few white pixels, just near the boundary. When I executed the code, all points are lie on the white line (as showed result)...again trying to visulize the plot.

[MMSAAH]

Here is the image zoomed. Many points are outside the red curve.

Answer 3

[MMSAAH]

The problem still exists.

Could anyone help me solving this issue please.