img_wave_vert.h

编译环境： TI CCS2.20.18 芯片：TI64X系列都可 功能：实现采集图像的边沿检测

/*      exactly two banks (one word) so that loads to any succesive         */
/*      lines may be parallelized together.                                 */
/*                                                                          */
/*      This code is a LITTLE ENDIAN implementation.                        */
/*                                                                          */
/*  NOTES                                                                   */
/*      This code masks interrupts for nearly its entire duration.  As a    */
/*      result the code is interrupt tolerant but not interruptible.        */
/*                                                                          */
/*  C CODE                                                                  */
/*      void IMG_wave_vert                                                  */
/*      (                                                                   */
/*          const short *restrict                                           */
/*                      *restrict in_data,   // Array of row pointers //    */
/*          const short *restrict qmf,       // Low pass QMF filter   //    */
/*          const short *restrict mqmf,      // High pass QMF filter  //    */
/*          short       *restrict out_ldata, // Low pass output data  //    */
/*          short       *restrict out_hdata, // High pass output data //    */
/*          int cols                     // Length of rows to process //    */
/*      )                                                                   */
/*      {                                                                   */
/*          const int M = 8;                                                */
/*          int            i, iters, j;                                     */
/*          int            sum_h, sum_l;                                    */
/*          int            prod_h, prod_l;                                  */
/*                                                                          */
/*          short          res_h, res_l;                                    */
/*          short          xdata, hdata, ldata;                             */
/*          short          *filt_ptr;                                       */
/*                                                                          */
/*          // ------------------------------------------------------ //    */
/*          //  iters: variable for the # of loop iterations.         //    */
/*          //                                                        //    */
/*          //  Both the low pass and the high pass filters produce   //    */
/*          //  'iters' points, which is also the width of the input  //    */
/*          //  line.  The low-pass filter reads filter coefficients  //    */
/*          //  from qmf and the high pass filter reads filter        //    */
/*          //  coefficients from the conjugate mirror filter. In     //    */
/*          //  addition note that the low-pass filter coefficients   //    */
/*          //  are read in increasing order while the high pass the  //    */
/*          //  filter coefficients are read in the opposite order.   //    */
/*          // ------------------------------------------------------ //    */
/*          iters = cols;                                                   */
/*                                                                          */
/*          // ------------------------------------------------------ //    */
/*          //  Since the filters have fractional point coefficients, //    */
/*          //  all math is done using Q15 fixed-point arithmetic.    //    */
/*          //  Qr is the associated round value and is set as        //    */
/*          //  follows:                                              //    */
/*          //                                                        //    */
/*          //      #define Qpt 15                                    //    */
/*          //      #define Qr 16384                                  //    */
/*          //                                                        //    */
/*          //  Low-Pass filter: ihptr contains 8 pointers which      //    */
/*          //  point to input lines. The filters are placed          //    */
/*          //  vertically and input data is read from 8 seperate     //    */
/*          //  lines. Hence data-reuse is not possible when          //    */
/*          //  traversing horizontally. sum_l is initialized to Qr   //    */
/*          //  and contains the low-pass FIR sum at the end of the   //    */
/*          //  j loop. sum_h contains the accumulator result for     //    */
/*          //  the high pass filter in a similar fashion.  M is      //    */
/*          //  assumed to be 8 by all kernels and is # filter taps   //    */
/*          //  for D4.                                               //    */
/*          // ------------------------------------------------------ //    */
/*                                                                          */
/*          for ( i = 0; i < iters; i++)                                    */
/*          {                                                               */
/*              sum_l    = Qr;                                              */
/*              filt_ptr = qmf;                                             */
/*                                                                          */
/*              for ( j = 0; j < M; j++)                                    */
/*              {                                                           */
/*                  xdata   =  in_data[j][i];                               */
/*                  ldata   =  *filt_ptr++;                                 */
/*                  prod_l  =  xdata * ldata;                               */
/*                  sum_l  +=  prod_l;                                      */
/*              }                                                           */
/*                                                                          */
/*              res_l    = (sum_l >> Qpt);                                  */
/*              *out_ldata++ = res_l;                                       */
/*          }                                                               */
/*                                                                          */
/*          // ------------------------------------------------------ //    */
/*          //  High-Pass filter:  ihptr contains 8 pointers which    //    */
/*          //  point to input lines.  The filters are placed         //    */
/*          //  vertically and input data is read from 8 seperate     //    */
/*          //  lines.  Hence data-reuse is not possible when         //    */
/*          //  traversing horizontally.  sum_h is initialized to     //    */
/*          //  Qr and contains the low-pass FIR sum at the end of    //    */
/*          //  the j loop.  sum_h contains the accumulator result    //    */
/*          //  for the high pass filter in a similar fashion.  M     //    */
/*          //  is # filter taps and is assumed to be 8 by all        //    */
/*          //  kernels.                                              //    */
/*          // ------------------------------------------------------ //    */
/*          for ( i = 0; i < iters; i++)                                    */
/*          {                                                               */
/*              sum_h    = Qr;                                              */
/*              filt_ptr = mqmf + M - 1;                                    */
/*                                                                          */
/*              for ( j = 0; j < M; j++)                                    */
/*              {                                                           */
/*                  xdata   =  in_data[j][i];                               */
/*                  hdata   =  *filt_ptr--;                                 */
/*                  prod_h  =  xdata * hdata;                               */
/*                  sum_h  +=  prod_h;                                      */
/*              }                                                           */
/*                                                                          */
/*              res_h    = (sum_h >> Qpt);                                  */
/*              *out_hdata++ = res_h;                                       */
/*          }                                                               */
/*      }                                                                   */
/*                                                                          */
/*  CYCLES                                                                  */
/*      cycles = 4*cols + 96  (both lowpass and highpass together)          */
/*                                                                          */
/*      For cols = 256, cycles = 1120.                                      */
/*      For cols = 512, cycles = 2144.                                      */
/*                                                                          */
/*  CODESIZE                                                                */
/*      888 bytes                                                           */
/*                                                                          */
/*  BIBLIOGRAPHY                                                            */
/*      Mallat, Stephane. "A Wavelet Tour of Signal Processing", pg. 309.   */
/* ------------------------------------------------------------------------ */
/*            Copyright (c) 2002 Texas Instruments, Incorporated.           */
/*                           All Rights Reserved.                           */
/* ======================================================================== */
#ifndef IMG_WAVE_VERT_H_
#define IMG_WAVE_VERT_H_ 1

void IMG_wave_vert
(
    const short *restrict
                *restrict in_data,   /* Array of row pointers */
    const short *restrict qmf,       /* Low pass QMF filter   */
    const short *restrict mqmf,      /* High pass QMF filter  */
    short       *restrict out_ldata, /* Low pass output data  */
    short       *restrict out_hdata, /* High pass output data */
    int cols                     /* Length of rows to process */
);

#endif
/* ======================================================================== */
/*  End of file:  img_wave_vert.h                                           */
/* ------------------------------------------------------------------------ */
/*            Copyright (c) 2002 Texas Instruments, Incorporated.           */
/*                           All Rights Reserved.                           */
/* ======================================================================== */