Why is the compressed Image White?

I working on watermarking scheme using the DWT domain. That's not even the problem, my problem is after decomposing the image into cA, CH, cV, cD, after achieving this i re-decomposed the cA into cA1, cH1, cV1, cD1. I took the cA1 compressed it to jpg using the imwrite function White image is showing. Below is my code:

clear ALL,

clc,

close ALL;

%% Facial image (cover image)

FacialIMGpath = 'C:\Users\foday\Documents\Thesis\originalImage\1-041.png';

host = imread(FacialIMGpath);

host=host(:,:,1);

% [rows, cols]=size(host);

figure (1);

subplot(1,3,1)

imshow(host,[]);

title('Original Image');

%% Adding the Haar wavelet to the host image

[host_LL,host_LH,host_HL,host_HH]=dwt2(host,'haar');

[host_LL1,host_LH1,host_HL1,host_HH1]=dwt2(host_LL,'haar');

% [rows, cols]= size(host_LL);

subplot(1,3,2)

imshow((host_LL1),[]);

title('MULTILEVEL DECOM IMG');

%% JPEG COMPRESSION

imwrite(host_LL1, 'compressedimage.jpg', 'jpg', 'Quality', 90);

JPeg_attack =imread('C:\Users\foday\Documents\Thesis\double watermark\LL\LL multi_level\compressedimage.jpg');

[rows, cols]= size(JPeg_attack);

subplot(1,3,3)

imshow(uint8(JPeg_attack),[]);

Kindly need your assistance

Answer 1

[Image Analyst]

I see you're using [] in imshow, so that's good - it should be able to handle floating point images.

I think the problem may be in

imwrite(host_LL1, 'compressedimage.jpg', 'jpg', 'Quality', 90);

What is the class of host_LL1? Is it uint8 or uint16 (should be no problem)?

Or is it double -- if so, that is probably the problem.