what does the L-shaped bracket mean?

N1 = N2 = 4
xi = ith pixel of 4 x 4 block

What does the 'L - shaped bracket' mean? How to write code for alpha and beta?

[KALYAN ACHARJYA]

Is this Matlab ralated question?

Check here for different Maths Sysmbols

Answer 1

[Image Analyst]

Just consider them as regular, normal brackets, or ignore them entirely.

xBar = mean(x(:));
alpha = mean(x(x >= xBar)); % Mean of x where x >= xBar
beta = mean(x(x < xBar)); % Mean of x where x < xBar

[Image Analyst]

Since N is 4 this appears to be a sliding window operation, like a convolution. So the whole thing can be done with conv2() like I showed you in your other question. Then just threshold to values above or below zero to get the thresholded images -- the alpha and beta images. There is no need to round down with floor to create the images.

[Elysi Cochin]

sir what about the variable t

[Image Analyst]

t is the number of elements in the block, which is 16 for a 4x4 block, or the number of pixels in the image if you're doing it over the whole image. Like I said, since it's only 4x4 I think it's a sliding window and you'd just use the code I gave you in the other answer and not even use t.

Answer 2

[Stephen23]

Those brackets are actually the common way in mathematics to represent the floor function:

https://www.mathsisfun.com/sets/function-floor-ceiling.html

https://en.wikipedia.org/wiki/Floor_and_ceiling_functions

https://en.wikipedia.org/wiki/Bracket_(mathematics)#Floor/ceiling_functions_and_fractional_part

They are unlikely to be a formatting error.