function IDCT(const Vec: TMtxVec; VecIndex: Integer; Index: Integer; Len: Integer): TMtxVec;
The inverse discrete cosine transform (DCT).
| # | Name | Type | Description |
|---|---|---|---|
| 1 | Vec | TMtxVec | |
| 2 | VecIndex | Integer | |
| 3 | Index | Integer | start index |
| 4 | Len | Integer | element count |
Result: stored in self (calling object), returns self for chaining
Remarks:
Calculate the inverse discrete cosine transform (DCT) from Vec elements [VecIndex]..[VecIndex+Len-1] and store the results in the calling object elements [Index]..[Index+Len-1]. The Len parameter must be the power of two. Size and Matrix.Complex properties of the calling Matrix must be set explicitly. An exception is raised if Matrix.ConditionCheck is True and array borders are overrun.