📄 img_corr_3x3.h
字号:
/* ======================================================================== */
/* TEXAS INSTRUMENTS, INC. */
/* */
/* IMGLIB DSP Image/Video Processing Library */
/* */
/* Release: Revision 1.04b */
/* CVS Revision: 1.4 Sun Sep 29 03:32:19 2002 (UTC) */
/* Snapshot date: 23-Oct-2003 */
/* */
/* This library contains proprietary intellectual property of Texas */
/* Instruments, Inc. The library and its source code are protected by */
/* various copyrights, and portions may also be protected by patents or */
/* other legal protections. */
/* */
/* This software is licensed for use with Texas Instruments TMS320 */
/* family DSPs. This license was provided to you prior to installing */
/* the software. You may review this license by consulting the file */
/* TI_license.PDF which accompanies the files in this library. */
/* ------------------------------------------------------------------------ */
/* Copyright (C) 2003 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/* ======================================================================== */
/* ======================================================================== */
/* Assembler compatibility shim for assembling 4.30 and later code on */
/* tools prior to 4.30. */
/* ======================================================================== */
/* ======================================================================== */
/* End of assembler compatibility shim. */
/* ======================================================================== */
/* ======================================================================== */
/* TEXAS INSTRUMENTS, INC. */
/* */
/* NAME */
/* corr_3x3: 3x3 correlation with rounding for 8 bit data */
/* */
/* REVISION DATE */
/* 14-Mar-2002 */
/* */
/* USAGE */
/* This routine is C-callable and can be called as: */
/* */
/* void IMG_corr_3x3 */
/* ( */
/* const unsigned char *i_data, // input image // */
/* int *restrict o_data, // output image // */
/* const unsigned char mask[3][3], // convolution mask // */
/* int x_dim, // width of image // */
/* int n_out // number of outputs // */
/* ); */
/* */
/* DESCRIPTION */
/* The correlation performs a point by point multiplication of the */
/* 3 by 3 mask with the input image. The result of the nine */
/* multiplications are then summed up together to produce a */
/* convolution sum. This sum is then stored to the output array. */
/* */
/* The image mask to be correlated is typically part of the input */
/* image and indicates the area of the best match between the */
/* input image and mask. The mask is moved one column at a time, */
/* advancing the mask over the portion of the row specified by */
/* 'n_out'. When 'n_out' is larger than 'x_dim', multiple rows */
/* will be processed. */
/* */
/* An application may call this kernel once per row to calculate */
/* the correlation for an entire image: */
/* */
/* for (i = 0; i < rows; i++) */
/* { */
/* IMG_corr_3x3(&i_data[i * x_dim], &o_data[i * n_out], */
/* mask, x_dim, n_out); */
/* } */
/* */
/* Alternately, the kernel may be invoked for multiple rows at */
/* a time, although the two outputs at the end of each row will */
/* have meaningless values. For example: */
/* */
/* IMG_corr_3x3(i_data, o_data, mask, x_dim, 2 * x_dim); */
/* */
/* This will produce two rows of outputs into 'o_data'. The */
/* outputs at locations o_data[x_dim - 2], o_data[x_dim - 1], */
/* o_data[2*x_dim - 2] and o_data[2*x_dim - 1] will have */
/* meaningless values. This is harmless, although the application */
/* will have to account for this when interpreting the results. */
/* */
/* ASSUMPTIONS */
/* The array pointed to by o_data does not alias with the array */
/* pointed to by i_data or mask. */
/* */
/* The number of outputs 'n_out' must be a multiple of 8. In cases */
/* where 'n_out' is not a multiple of 8, most applications can safely */
/* round 'n_out' up to the next multiple of 8 and ignore the extra */
/* outputs. This kernel does not round 'n_out' up for the user. */
/* */
/* NOTE */
/* This kernel is fully interruptible. */
/* */
/* MEMORY NOTE */
/* This kernel places no restrictions on the alignment of its input. */
/* */
/* No bank conflicts occur. */
/* */
/* This code assumes a LITTLE ENDIAN configuration. */
/* */
/* TECHNIQUES */
/* The inner loops are unrolled completely, and the outer loop is */
/* unrolled 8 times. */
/* */
/* We use 3 DOTPU4s to calculate the 3 rows of each output pixel. */
/* We then accumulate the 3 DOTPU4s to a 32-bit result and store */
/* them out. (Note that only 3 of every 4 8-bit MPYs in the DOTPU4 */
/* is actually used. The fourth MPY is unused.) */
/* */
/* We use non-aligned loads and stores to avoid alignment issues. */
/* */
/* CYCLES */
/* cycles = 1.5 * n_out + 22 */
/* For n_out = 248, cycles = 394. */
/* */
/* This number includes 6 cycles of function call overhead. The */
/* exact overhead will vary depending on compiler options used. */
/* */
/* CODESIZE */
/* 296 bytes. */
/* ------------------------------------------------------------------------ */
/* Copyright (c) 2003 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/* ======================================================================== */
#ifndef IMG_CORR_3X3_H_
#define IMG_CORR_3X3_H_ 1
void IMG_corr_3x3
(
const unsigned char *i_data, // input image //
int *restrict o_data, // output image //
const unsigned char mask[3][3], // convolution mask //
int x_dim, // width of image //
int n_out // number of outputs //
);
#endif
/* ======================================================================== */
/* End of file: img_corr_3x3.h */
/* ------------------------------------------------------------------------ */
/* Copyright (c) 2003 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/* ======================================================================== */
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -