Specifications

Linear Image Transforms
7-9
7
DCT2D
Computes the forward
or inverse 2D DCT of an
image.
void iplDCT2D(IplImage* srcImage , IplImage* dstImage ,
int
flags );
srcImage Thesourceimage.
dstImage The resultant image containing the DCT
coefficients. This image must be a multi-channel
image containing the same number of channels as
srcImage . The data type for the image must be
8, 16 or 32 bits.
This image cannot be the same as the input image
srcImage (that is, an in-place operation is not
allowed).
flags Specifies how to perform the DCT. This is an
integer whose bits can be assigned the following
values using bitwise logical
OR:
IPL_DCT_Forward Do forward transform.
IPL_DCT_Inverse Do inverse transform.
IPL_DCT_Free Only free all working arrays and exit.
IPL_DCT_UseInpBuf
Use the input image array for the intermediate
calculations. The performance of DCT increases, but
the input image is destroyed. You may use this value
only if both the source and destination image data types
are 16-bit signed.