Community Profile # Abdul Gaffar

### University of Lucknow

Last seen: 12 maanden ago Active since 2017

Researcher in Cryptography and Steganography

Programming Languages:
MATLAB
Spoken Languages:
English, Hindi

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Question

How to find the 2-D correlation coefficient between the two images, each having same pixels?
I have to calculate the 2-D correlation coefficient between the images img1 and img2, each having same pixels. I am doing the fo...

meer dan een jaar ago | 1 answer | 0

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Question

How to read a very large number, say of 700 digits?
If I have a number, say N of 700 digits, then how can I read it? I have tried using ELLIPSIS (...) as: N = 1234567890123 ... ...

meer dan een jaar ago | 3 answers | 0

### 3

Question

Error in running built-in command "audioread"
The problem originates by running a code, which was found on MathWorks help forum, and is: [filename, pathname] = uigetfile('*....

bijna 2 jaar ago | 1 answer | 0

### 1

Question

How to calculate entropy of a DICOM image (16-bit depth)?
According to MatLab, By default, entropy uses two bins for logical arrays and 256 bins for uint8, uint16, or double arrays. e...

bijna 2 jaar ago | 1 answer | 0

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Question

3D Histogram of a true color (RGB) image
I have to plot 3D histogram of a true color image, as shown in the attached screenshot.

meer dan 2 jaar ago | 0 answers | 0

### 0

Question

How to convert 8 Binary images of size 256 x 256 into a Grayscale image of same size, i.e., 256 x 256?
Suppose, I have 8 Binary images of same size. Then, I want to combine binary bits of all 8 images pixel-wise to form 'a' 8-bit d...

meer dan 2 jaar ago | 2 answers | 0

### 2

Question

How to process a 'function' that take inputs as blocks from two matrices
Suppose there are two matrices A and B of size 6 x 6 (small size for convenience). If there is a function say, mat which takes i...

bijna 3 jaar ago | 1 answer | 0

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Question

How to convert numbers into characters other than in the range 32-127?
I have the following code: A = [10, 23, 90, 125, 145, 250]; B = char(A) % Converts double into character C = ' Z}ú'; ...

ongeveer 3 jaar ago | 1 answer | 0

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Question

How to decrypt the cipher-text generated by RC4 stream cipher?
I am encrypting 'text' message using keystream generated by RC4 stream cipher. But while decrypting the ciphertext generated by ...

ongeveer 3 jaar ago | 0 answers | 0

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Question

How to use VPA (variable precision arithmetic) in calculating HH band via dwt on an image?
I have the following code: img = imread('cameraman.tif'); [LL,LH,HL,HH] = dwt2(img, 'db1'); I have to calculate HH band usin...

meer dan 3 jaar ago | 1 answer | 0

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Question

How to replace last 3 digits in a floating point number by another 3 digits
Let x = -3.141592653589793; a = 287; then how can I replace last 3 digits of x i.e. 793 by a ?

meer dan 3 jaar ago | 2 answers | 0

### 2

Question

How to retrieve first 4 digits after decimal point?
I have to retrieve first 4 digits after decimal point in HH band of the following code: img = imread('cameraman.tif'); a = im...

meer dan 3 jaar ago | 1 answer | 0

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Question

How to retrieve last 3 digits from each entry of a matrix of order 3 x 4 ?
Let A = [35679, 35678, 35677, 35676; 35675, 35674, 35673, 35672; 35671, 35670, 35669, 35668]; how can I extract last 3 digits f...

meer dan 3 jaar ago | 2 answers | 0

### 2

Question

How to convert binary bits of a vector, say m, after rotating it left by 1 bit, into decimal ?
m = [16, 10]; % 1x2 array a = fi(m, 0, 8, 0); b = bin(bitrol(a, 1)); % Left rotate a by 1 bit b = 00100000 00010100 ...

ongeveer 4 jaar ago | 1 answer | 0

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Question

Embedding Factor used in Steganography
What is embedding factor like e^(-4), used to balance the Embedding effect of a secret image into a Cover image in Steganography...

ongeveer 4 jaar ago | 0 answers | 0

### 0

Question

How to convert a matrix having integer entries (+ or -) into binary ?
i have code, a = -123; % your float point number n = 16; % number bits for integer part of your number ...

ongeveer 5 jaar ago | 1 answer | 0

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Question

How to find second level 2D inverse wavelet transform to obtain the original image?
Good afternoon sir, i am working on stegonography.How to find second level 2D inverse wavelet transform to obtain the original i...

ongeveer 5 jaar ago | 0 answers | 0

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Question

Negative decimal fraction to binary
Good afternoon sir, how to convert negative decimal fraction into binary (8 bits) and vice-versa? For eg. Convert - 0.0728 to...

ongeveer 5 jaar ago | 2 answers | 0

### 2

Question

Workspace variables in R2015a
Good morning sir, before R2015a MATLAB version, i was using MATLAB 2013. In R2013a matlab, varibles were shown with their minimu...

ongeveer 5 jaar ago | 1 answer | 0

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Question

RGB image encryption using RSA algorithm
Sir, i have an RGB image. I want to encrypt it using RSA algorithm. Please provide the code

ongeveer 5 jaar ago | 0 answers | 0

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Question

How to shuffle rows of a matrix, say order 4, with the help of set having 4 elements, several times?
Let R=[1,2,3,4;5,6,7,8;9,10, 11,12;13,14,15,16]; k=[3,4,1,2]; for i=1:4 R1(i,:)=R(k(i),:); end for i=1:4...

meer dan 5 jaar ago | 1 answer | 0

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Question

Writing m*n matrix into single array
I want to write m*n matrix into single array

meer dan 5 jaar ago | 1 answer | 0