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 calculate DCT?
The DCT Transform Matrix
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 the DCT coefficient?
DCT coefficient (0,0) is the DC coefficient, or average sample value. Since natural images tend to vary only slightly from sample to sample, low frequency coefficients are typically larger values and high frequency coefficients are typically smaller values. The 8×8 DCT is defined in Figure 5.21.
Is 2d DCT separable?
2-D DCT basis functions for . Separable computation of the 2-D DCT (or indeed any separable transform) can be visualized as shown in Figure 5.10. Figure 5.10.