Image Processing Toolbox

idct2

Compute two-dimensional inverse discrete cosine transform

Syntax

• B = idct2(A)
  B = idct2(A,m,n)
  B = idct2(A,[m n])
  

Description

B = idct2(A) returns the two-dimensional inverse discrete cosine transform (DCT) of A.

B = idct2(A,m,n) or B = idct2(A,[m n]) pads A with zeros to size m-by-n before transforming. If [m n] < size(A), idct2 crops A before transforming.

For any A, idct2(dct2(A)) equals A to within roundoff error.

Class Support

The input matrix A can be of class double or of any numeric class. The output matrix B is of class double.

Algorithm

idct2 computes the two-dimensional inverse DCT using

See Also

dct2, dctmtx, fft2, ifft2

References

[1]  Jain, Anil K. Fundamentals of Digital Image Processing. Englewood Cliffs, NJ: Prentice Hall, 1989. pp. 150-153.

[2]  Pennebaker, William B., and Joan L. Mitchell. JPEG: Still Image Data Compression Standard. New York: Van Nostrand Reinhold, 1993.

hsv2rgb

ifft2