Low contrast object detection

I am trying to write a matlab code to draw a line over the rope in the attached photo. Probably due to the low contrast between rope (object) an the background, I was unabel to detect the edges / identify the location of the rope. Can someone help me ?

I have tried many methods including methods such as Radon transform and peak detection. But no luck so far.

Thanks in adance.

Answer 1

[JESUS DAVID ARIZA ROYETH]

I leave you an example:

close all
RGB=imread('negativo/drone_image.jpg');
BW = (RGB(:,:,1) >= 142 ) & (RGB(:,:,1) <= 178) & ...
    (RGB(:,:,2) >= 93 ) & (RGB(:,:,2) <= 215) & ...
    (RGB(:,:,3) >= 182 ) & (RGB(:,:,3) <= 226);
BW = imdilate(BW,strel('line',300,90)); 
BW = bwpropfilt(BW, 'MajorAxisLength', [500, 5262]);
imshowpair(RGB,BW,'montage')