Can anyone combined these operations for a gray scale image?

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  1. Step1-A grayscale image--->DWT
  2. Step2-Grayscale Image--->Apply Canny Edge Detector
  3. Step3-Combined step2 & step1 to make a Defocus Image
  6 Comments
Haseeb Hassan
Haseeb Hassan on 25 Apr 2018
Edited: Image Analyst on 26 Apr 2018
%%Apply DWT
dwt_image=dwt2(x,'haar');
dwt_im2=imresize(dwt_image,[rows colm]);
gray_im=im2bw(dwt_im2);
figure ;imshow(gray_im);
%%Applying Canny Edge Detector
BW1=edge(x,'Canny');
result=and(gray_im,BW1);
As from your code after getting wavelet transform you assigned this matrix to gray_im matrix and then you concatenated these two matrices by AND operator and on other side we just apply simple canny edge detector to our input image but in both cases the result image is same. The first question is why you convert the wavelet transform matrix to binary image and if you applied after comparison with our output image (by applying simple canny edge detector) are same.
KALYAN ACHARJYA
KALYAN ACHARJYA on 26 Apr 2018
Just for comparison purpose only. I followed the steps as per your questions.

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Accepted Answer

KALYAN ACHARJYA
KALYAN ACHARJYA on 24 Apr 2018
%I tried as per your statement flow-here it is, but did not find any sense of defocus.
%Result is binary image.
lx=imread('1.jpg');
x=rgb2gray(lx);
[rows colm]=size(x);
%%Apply DWT
dwt_image=dwt2(x,'haar');
dwt_im2=imresize(dwt_image,[rows colm]);
gray_im=im2bw(dwt_im2);
%%Applying Canny Edge Detector
BW1=edge(x,'Canny');
result=and(gray_im,BW1);
%%Display
binaryImage=uint8(255 * result);
result1=[lx,cat(3, binaryImage, binaryImage, binaryImage)];
imshow(result1);
  1 Comment
Haseeb Hassan
Haseeb Hassan on 30 Apr 2018
Okay Sir can you explain me this by code . "2D wavelet transformation of the input image with a specific threshold to produce a binary image". I am confused about the specific threshold where we can use or how we can use the specific threshold in DWT.

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