2d dct matlab

1. What is 2d DCT?
2. How to use dct2 function in Matlab?
3. How does Matlab calculate DCT?
4. What is Dctmtx command in Matlab?

What is 2d DCT?

Description. The 2-D DCT block calculates the two-dimensional discrete cosine transform of an image. Suppose f(x,y) is the input image of dimension M-by-N, the equation for the 2-D DCT is. F ( m , n ) = 2 M N C ( m ) C ( n ) ∑ x = 0 M − 1 ∑ y = 0 N − 1 f ( x , y ) cos ( 2 x + 1 ) m π 2 M cos ( 2 y + 1 ) n π 2 N.

How to use dct2 function in Matlab?

Description. B = dct2( A ) returns the two-dimensional discrete cosine transform of A . The matrix B contains the discrete cosine transform coefficients B(k₁,k₂). B = dct2( A ,[ m n ]) pad the matrix A with 0 s to size m -by- n before applying the transformation.

How does Matlab calculate DCT?

The two-dimensional DCT of A can be computed as B=T*A*T' . Since T is a real orthonormal matrix, its inverse is the same as its transpose. Therefore, the inverse two-dimensional DCT of B is given by T'*B*T .

What is Dctmtx command in Matlab?

example. D = dctmtx( n ) returns the n -by- n discrete cosine transform (DCT) matrix, which you can use to perform a 2-D DCT on an image.