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/* ======================================================================== */
/* TEXAS INSTRUMENTS, INC. */
/* */
/* IMGLIB DSP Image/Video Processing Library */
/* */
/* Release: Revision 1.04b */
/* CVS Revision: 1.7 Sun Sep 29 07:07:22 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. */
/* ======================================================================== */
/*==========================================================================S*/
/* */
/* TEXAS INSTRUMENTS, INC. */
/* */
/* NAME */
/* Perimeter: Detection of the boundary of a binary image */
/* */
/* REVISION DATE */
/* 21-Aug-2001 */
/* */
/* USAGE */
/* This routine is C callable, and has the following C prototype: */
/* */
/* int IMG_perimeter */
/* ( */
/* const unsigned char *restrict in, // Input image // */
/* int cols, // Width of input // */
/* unsigned char *restrict out // Output image // */
/* ); */
/* */
/* DESCRIPTION */
/* This routine produces the boundary of a binary image. It echoes */
/* the boundary pixels with a value of 0xFF and sets the other pixels */
/* as 0. Detection of the boundary of a binary image is a segmentation */
/* problem and is done by examining spatial locality of the neighboring */
/* pixels. This is done by using the four connectivity algorithm */
/* */
/* pix_up */
/* pix_lft pix_cent pix_rgt */
/* pix_dn */
/* */
/* The output pixel at location pix_cent is echoed as a boundary pixel */
/* if pix_cent is non-zero and any one of its four neighbors is zero */
/* The four neighbors are shown and stand for the foll: */
/* */
/* pix_up: top pixel */
/* pix_lft: left pixel */
/* pix_rgt: right pixel */
/* pix_dn: bottom pixel */
/* */
/* ASSUMPTIONS */
/* input image must be double-word aligned */
/* cols must be a multiple of 16 */
/* */
/* MEMORY NOTE */
/* No bank conflicts are expected for this kernel. */
/* */
/* TECHNIQUES */
/* */
/* Use double word wide loads and bring in pixels along three lines which */
/* we shall call top, mid and bot. Use split compares to compare if pix- */
/* els are greater than or equal to zero. Use the 4 lsb's to find out */
/* the result. Prepare an 8 bit mask using the result of 2 such split */
/* compares. Perform this operation for the top, middle and botton. */
/* Logically invert the result of mid, left shift and right shift and */
/* add the context information by setting the 8 th bit or the 1st bit. */
/* Use xpnd4 and bitc4 to perform expansion and bit count. Store output */
/* pixels as double word. The actual handassembly code is unrolled once */
/* and computes 16 output pixels in 10 cycles */
/* */
/* CYCLES */
/* 10 * cols/16 + 55 */
/* cols = 720, 505 cycles */
/* */
/* CodeSize: 600 bytes */
/* */
/*==========================================================================S*/
/* Copyright (c) 2003 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/*==========================================================================S*/
#ifndef IMG_PERIMETER_H_
#define IMG_PERIMETER_H_ 1
int IMG_perimeter
(
const unsigned char *restrict in, /* Input image */
int cols, /* Width of input */
unsigned char *restrict out /* Output image */
);
#endif
/* ======================================================================== */
/* End of file: img_perimeter.h */
/* ------------------------------------------------------------------------ */
/* Copyright (c) 2003 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/* ======================================================================== */