Problems with extracting a watermark - image

Question

I'm working on watermarking and recently I try to developp the method found here for a blind color watermarking. For embedding the watermark every is Ok I got great results but in extraction part I don't know why I have a black watermark image and it doesn't look like the original one!! Here is the code I use for extraction:
function extracted_mark=extract_dyn_U(rgb_wateramrked,ix,iy);
% rgb_wateramrked=imread('Watermarked_rgbImage.jpg'); %%% read original image
img=rgb2ycbcr(rgb_wateramrked); %%%convert to ycbcr color space
imgy=img(:,:,1);
imgcb=img(:,:,2);
imgcr=img(:,:,3);
[ca1,ch1,cv1,cd1]=dwt2(imgy,'haar'); %%% Apply dwt 2level on ca
[ca2,ch2,cv2,cd2]=dwt2(ca1,'haar');
[m n]=size(ca2);
blocksize=m/32
%********************Extraction**********************
watermark1=zeros(32,32); % define a zero matrix with the original watermak size
for k=1:32
for j=1:32
L=zeros(4,4);
L=ca2(ix:ix+blocksize-1,iy:iy+blocksize-1);
[U,S,V]=svd(L);
if abs(U(2,1))>= abs(U(3,1))
watermark1(k,j)=1;
else
watermark1(k,j)=0;
end
end
end
imshow(watermark1);
extracted_mark=watermark1;
end
end
It just doesn't give me the right extracted watermark :( and in this work I tried with a binary image from the beginning, but I actually need to convert a color watermark from RGB to decimal then to binary so I can use it. and the issue I got too is when I will have an extracted watermark how to reconverted from binary to decimal then RGB!! thank you in advance
This is th original binary watermark (left) and the result after extraction (right). I expect to have an extracted watermark as the original one.