flot8.h

lapped transforms for images. lapped transform is a very fast algorithm to replace dct.

/*
 * Prototypes for transform routines
 *
 * H. S. Malvar, 6/11/97
 */

typedef  unsigned char    pixel;
typedef  short            int16;
typedef  long             int32;
typedef  unsigned char    uint8;
typedef  unsigned short   uint16;
typedef  unsigned int     uint;

#define  BLOCKSIZE  64      /* the only supported block size */
#define  NBLOCK     8       /* number of pixels in a block row or column */
#define  DCBIAS     8192    /* value of DC coefficient for blocks */
#define  DCT        1
#define  LOT        2
#define  LBT        3
#define  HLBT       4

void forward_dct(pixel **p, int16 **img, int nrows, int ncols);
void inverse_dct(int16 **img, pixel **p, int nrows, int ncols);
void forward_lot(pixel **p, int16 **img, int nrows, int ncols, int type);
void inverse_lot(int16 **img, pixel **p, int nrows, int ncols, int type);
void forward_hlbt(pixel **p, int16 **img, int nrows, int ncols);
void inverse_hlbt(int16 **img, pixel **p, int nrows, int ncols);