MATLAB: Euclidian Norm and Brightness between 2 images

image analysisimage processing

I really appreciate your help and I would be soo grateful if you help me with this?, I have two questions…

How to calculate these two equations if I have two images(RGB)as an input,

1- Euclidian Norm between 2 images, the equation is shown below: 
[this measure is used to find the set of the closest palette color in Euclidian norm] 
d= sqrt ( (R1-R2)^2 + (G1-G2)^2 + (B1-B2)^2 ); 
2-  Brightness between 2 images, the equation is shown below:
[Brightness information, which measures the brightness of the cover image and the Stego image and compute the difference between the brightness of the cover image and the brightness of the Stego image, this is done by measuring the length of the RGB vector for both cover and Stego images. The calculation is done according to the following
formula:]
L= sqrt (R^2 + G^2 + B^) ;

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Perfect, Thank you so much...

Related Solutions

MATLAB: Solving two trigonometric equations, two unknowns

There is no need for the answer to be that complicated. Here is a method entirely independent of 'solve' and 'fsolve'.

 R*cos(x)-L1*cos(y)=L2*cos(p)
 R*sin(x)-L1*sin(y)=L2*sin(p)
 L1*cos(y) = R*cos(x)-L2*cos(p)
 L1*sin(y) = R*sin(x)-L2*sin(p)

Now square both sides of both equations and add them to get:

 (L1*cos(y))^2+(L1*sin(y))^2 = (R*cos(x)-L2*cos(p))^2+(R*sin(x)-L2*sin(p))^2
 L1^2 = R^2+L2^2-2*R*L2*(cos(x)*cos(p)+sin(x)*sin(p)) = R^2+L2^2-2*R*L2*cos(x-p)
 cos(x-p) = (R^2+L2^2-L1^2)/(2*R*L2)

There are two solutions for x in the interval between -pi and +pi which can be obtained using matlab's 'acos' function (assuming the above argument is between -1 and +1). For each of these x values, a corresponding y can be found using matlab's 'atan2' function:

 sin(y) = (R*sin(x)-L2*sin(p))/L1
 cos(y) = (R*cos(x)-L2*cos(p))/L1
 y = atan2((R*sin(x)-L2*sin(p))/L1,(R*cos(x)-L2*cos(p))/L1)

Thus there are two solutions for x and y lying within -pi to +pi. Any multiple of 2*pi can obviously be added or subtracted from either x or y for an infinitude of other possible solution pairs.

MATLAB: Circle-Circle Intersection ,dimension between circles

I don't know what is your D3. So go to the bottom of the code and set D3 to the one that you have.

% Area of a circular segment
A_CS=@(theta,r) ( (r^2/2)*(theta-sin(theta)) );
% Center of mass of a circular segment
X_CS=@(theta,r) ( (4*r*sin(theta/2)^3)/(3*(theta-sin(theta))) );
% x/y of circle-circle intersect
% It is assumed the coordinate system is at the center of the circle on the right
% r1 is the radius of the circle on the right,
% r2 is the radius of the circle on the left.
% d is the distance between the two centers.
xInt=@(r1,r2,d) ( (d^2-r2^2+r1^2)/(2*d) );
yInt=@(r1,r2,d) ( sqrt( (4*d^2*r1^2-(d^2-r2^2+r1^2)^2)/(4*d^2) ) );
theta1=@(x,y) atan(y/x);
theta2=@(x,y,d) atan( y / (d-x) );
Nom=@(r1,r2,d) (   d*pi*r2^2  ...
                 - A_CS(theta1(xInt(r1,r2,d),yInt(r1,r2,d)),r1)*X_CS(theta1(xInt(r1,r2,d),yInt(r1,r2,d)),r1) ...
                 - A_CS(theta2(xInt(r1,r2,d),yInt(r1,r2,d),d),r2)*(d-X_CS(theta2(xInt(r1,r2,d),yInt(r1,r2,d),d),r2)) );
Denom= @(r1,r2,d) (  pi*r2^2 ...
                   - A_CS(theta1(xInt(r1,r2,d),yInt(r1,r2,d)),r1) ...
                   - A_CS(theta2(xInt(r1,r2,d),yInt(r1,r2,d),d),r2) );
xHatch=@(r1,r2,d) (Nom(r1,r2,d)/Denom(r1,r2,d));
%%SET THESE NUMBERS ACCORDINGLY
r1=50/2; %[50mm]
r2=52/2; %[52mm]
D3=40; %[80mm]
%solving for D1
[D1,fval] = fsolve(@(d1) (D3-xHatch(r1,r2,d1)), D3-1 );
D2=D3-D1;
ezplot(@(x,y) (x.^2+y.^2-r1.^2),[-r1, D1+r2,-max(r1,r2),max(r1,r2)])
hold on
ezplot(@(x,y) ((x-D1).^2+y.^2-r2.^2),[-r1, D1+r2,-max(r1,r2),max(r1,r2)])
title('')
axis equal
line([xInt(r1,r2,D1) xInt(r1,r2,D1)],ylim,'Color','r')

Just note that I don't check if the r1 and r2 and D3 are valid numbers. I am assuming that they are valid. For example if D3 > (r1+r2) there is no solution at all and this program generates an error or gives a wrong answer. So make sure that the numbers are set properly. Also if the left circle is too much inside the the right circle this code gives you wrong answer. Make sure that D1<D3 at the end. and xInt(r1,r2,D1)>0;

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Related Solutions

MATLAB: Solving two trigonometric equations, two unknowns

MATLAB: Circle-Circle Intersection ,dimension between circles

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