Euclidian Norm and Brightness between 2 images

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^) ;

[shikha mangal]

hi i want to ask something related to the above question.

i want to calculate difference matrix between two rgb images by applying the euclidean distance formula on them,and the difference matrix should also be an image.is it possible?

Actually i have to use that matrix for further operation to generate reference background image of my frame sequence.please help me with this.i am truely in need.thanks

Answer 1

[Junaid]

then I guess for L you can do following.

R1 = R1(:); R2 = R2(:);
G1 = G1(:); G2 = G2(:);
B1 = B1(:); B2 = B2(:);

L1 = sqrt(sum(double((R1.^2 + G1.^2 + B1.^2)))) ;
L2 = sqrt(sum(double((R2.^2 + G2.^2 + B2.^2)))) ;

[Hamsah]

Perfect, Thank you so much...

[Junaid]

if it is exactly what you wanted then please accept the answer so that other might know about it :-)

[Hamsah]

sure accepted

[Junaid]

:-) Thanks.. usually the answer which fulfill the question is accepted ;).

[Hamsah]

Sorry i didn't know this is my first time...

[Junaid]

that is all right :-)

[Takeoff Groups]

superb

Answer 2

[Junaid]

You question is not quite clear, if you take the Euclidean norm between two images, then the formula you have written would return a matrix. I guess you want to get euclidean norm between two images as one scalar number right ? If so then based on your formula I have written code in steps.

Let A, and B be the two RGB images with same dimensions.

R1 = A(:,:,1); R2 = B(:,:,1);
G1 = A(:,:,2); G2 = B(:,:,2);
B1 = A(:,:,3); B2 = B(:,:,3);

s = (R1-R2).^2+(G1-G2).^2+(B1-B2).^2;
s = s(:);

d= sqrt(sum(s)); % this is euclidean norm

As your formula for Brightness can be computed as follow

L = sqrt(double((R1.^2 + G1.^2 + B1.^2))) ;

Here L is the Brightness of image 1 by your formula, it is Matrix. I m not very clear about your formula.

[EDITED, typo fixed: G1/2 and B1/2 inserted]

[Hamsah]

Thankx alot for the first equation. but for the brightness equation i also want a scalar number, sorry for not being clear because im new on these equations.

Answer 3

[Walter Roberson]

Hint: X.^2 instead of X^2

[Hamsah]

So, How? sorry you didn't answer the question!!!