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/*====================================================================*
- Copyright (C) 2001 Leptonica. All rights reserved.
- This software is distributed in the hope that it will be
- useful, but with NO WARRANTY OF ANY KIND.
- No author or distributor accepts responsibility to anyone for the
- consequences of using this software, or for whether it serves any
- particular purpose or works at all, unless he or she says so in
- writing. Everyone is granted permission to copy, modify and
- redistribute this source code, for commercial or non-commercial
- purposes, with the following restrictions: (1) the origin of this
- source code must not be misrepresented; (2) modified versions must
- be plainly marked as such; and (3) this notice may not be removed
- or altered from any source or modified source distribution.
*====================================================================*/
/*
* rotatefastalt.c
*
* Alternative (slightly slower) method for rotating color images,
* with antialiasing. This is here just for comparison with
* the better methods in the library.
*
* Includes these functions:
* pixRotateAMColorFast2()
* pixShiftRGB258()
* rotateAMColorFastLow2()
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h> /* required for sin and tan */
#include "allheaders.h"
static const l_float32 VERY_SMALL_ANGLE = 0.001; /* radians; ~0.06 degrees */
static PIX *pixRotateAMColorFast2(PIX *pixs, l_float32 angle, l_uint8 grayval);
static PIX *pixShiftRGB258(PIX *pixs);
static void rotateAMColorFastLow2(l_uint32 *datad, l_int32 w, l_int32 h,
l_int32 wpld, l_uint32 *datas,
l_int32 wpls, l_float32 angle,
l_uint8 grayval);
main(int argc,
char **argv)
{
char *filein, *fileout;
l_float32 angle, deg2rad;
PIX *pixs, *pixd;
static char mainName[] = "rotatefastalt";
if (argc != 4)
exit(ERROR_INT("Syntax: rotatefastalt filein angle fileout",
mainName, 1));
filein = argv[1];
angle = atof(argv[2]);
fileout = argv[3];
deg2rad = 3.1415926535 / 180.;
if ((pixs = pixRead(filein)) == NULL)
exit(ERROR_INT("pixs not read", mainName, 1));
startTimer();
pixd = pixRotateAMColorFast2(pixs, deg2rad * angle, 255);
fprintf(stderr, "Time for rotation: %7.3f sec\n", stopTimer());
pixWrite(fileout, pixd, IFF_JFIF_JPEG);
pixDestroy(&pixs);
pixDestroy(&pixd);
}
/*!
* pixRotateAMColorFast2()
*
* Input: pixs
* angle (radians; clockwise is positive)
* grayval (0 to bring in BLACK, 255 for WHITE)
* Return: pixd, or null on error
*
* Notes:
* - This rotates a color image about the image center.
* A positive angle gives a clockwise rotation.
* - It uses area mapping, dividing each pixel into
* 16 subpixels.
* - It creates a temporary 32-bit color image.
* - It is slightly slower than pixRotateAMColorFast(),
* which uses less memory because it does not create
* a temporary image.
*
* *** Warning: implicit assumption about RGB component ordering ***
*/
PIX *
pixRotateAMColorFast2(PIX *pixs,
l_float32 angle,
l_uint8 grayval)
{
l_int32 w, h, wpls, wpld;
l_uint32 *datas, *datad;
PIX *pixshft, *pixd;
PROCNAME("pixRotateAMColorFast2");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (pixGetDepth(pixs) != 32)
return (PIX *)ERROR_PTR("pixs must be 32 bpp", procName, NULL);
if (L_ABS(angle) < VERY_SMALL_ANGLE)
return pixClone(pixs);
if ((pixshft = pixShiftRGB258(pixs)) == NULL)
return (PIX *)ERROR_PTR("pixshft not defined", procName, NULL);
w = pixGetWidth(pixshft);
h = pixGetHeight(pixshft);
datas = pixGetData(pixshft);
wpls = pixGetWpl(pixshft);
pixd = pixCreateTemplate(pixshft);
datad = pixGetData(pixd);
wpld = pixGetWpl(pixd);
rotateAMColorFastLow2(datad, w, h, wpld, datas, wpls, angle, grayval);
pixDestroy(&pixshft);
return pixd;
}
/*!
* pixShiftRGB256()
*
* Makes a new 32 bpp image with the R, G and B components
* right-shifted by 2, 5 and 8 bits, respectively.
*/
PIX *
pixShiftRGB258(PIX *pixs)
{
l_int32 w, h, wpls, wpld, i, j;
l_uint32 word;
l_uint32 *datas, *datad, *lines, *lined;
PIX *pixd;
PROCNAME("pixShift258");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (pixGetDepth(pixs) != 32)
return (PIX *)ERROR_PTR("depth not 32 bpp", procName, NULL);
w = pixGetWidth(pixs);
h = pixGetHeight(pixs);
wpls = pixGetWpl(pixs);
datas = pixGetData(pixs);
if ((pixd = pixCreate(w, h, 32)) == NULL)
return (PIX *)ERROR_PTR("pixd not made", procName, NULL);
wpld = pixGetWpl(pixd);
datad = pixGetData(pixd);
for (i = 0; i < h; i++) {
lines = datas + i * wpls;
lined = datad + i * wpld;
for (j = 0; j < w; j++) {
word = *(lines + j);
*(lined + j) = ((word & 0xff000000) >> 2) |
((word & 0x00ff0000) >> 5) |
((word & 0x0000ff00) >> 8);
}
}
return pixd;
}
/*!
* rotateAMColorFastLow2()
*
* Alternative version for fast color rotation
*
* *** Warning: explicit assumption about RGB component ordering ***
*/
void
rotateAMColorFastLow2(l_uint32 *datad,
l_int32 w,
l_int32 h,
l_int32 wpld,
l_uint32 *datas,
l_int32 wpls,
l_float32 angle,
l_uint8 grayval)
{
l_int32 i, j, xcen, ycen, wm2, hm2;
l_int32 xdif, ydif, xpm, ypm, xp, yp, xf, yf;
l_uint32 edgeval, word;
l_uint32 *pword, *lines, *lined;
l_float32 sina, cosa;
xcen = w / 2;
wm2 = w - 2;
ycen = h / 2;
hm2 = h - 2;
sina = 4. * sin(angle);
cosa = 4. * cos(angle);
edgeval = (grayval << 24) | (grayval << 16) | (grayval << 8);
for (i = 0; i < h; i++) {
ydif = ycen - i;
lined = datad + i * wpld;
for (j = 0; j < w; j++) {
xdif = xcen - j;
xpm = (l_int32)(-xdif * cosa - ydif * sina + 0.5);
ypm = (l_int32)(-ydif * cosa + xdif * sina + 0.5);
xp = xcen + (xpm >> 2);
yp = ycen + (ypm >> 2);
xf = xpm & 0x03;
yf = ypm & 0x03;
/* if off the edge, write the input grayval */
if (xp < 0 || yp < 0 || xp > wm2 || yp > hm2) {
*(lined + j) = edgeval;
continue;
}
lines = datas + yp * wpls;
pword = lines + xp;
switch (xf + 4 * yf)
{
case 0:
word = *pword;
*(lined + j) = ((word & 0x3fc00000) << 2) |
((word & 0x0007f800) << 5) |
((word & 0x000000ff) << 8);
break;
case 1:
word = 3 * (*pword) + *(pword + 1);
*(lined + j) = (word & 0xff000000) |
((word & 0x001fe000) << 3) |
((word & 0x000003fc) << 6);
break;
case 2:
word = *pword + *(pword + 1);
*(lined + j) = ((word & 0x7f800000) << 1) |
((word & 0x000ff000) << 4) |
((word & 0x000001fe) << 7);
break;
case 3:
word = *pword + 3 * (*(pword + 1));
*(lined + j) = (word & 0xff000000) |
((word & 0x001fe000) << 3) |
((word & 0x000003fc) << 6);
break;
case 4:
word = 3 * (*pword) + *(pword + wpls);
*(lined + j) = (word & 0xff000000) |
((word & 0x001fe000) << 3) |
((word & 0x000003fc) << 6);
break;
case 5:
word = 2 * (*pword) + *(pword + 1) + *(pword + wpls);
*(lined + j) = (word & 0xff000000) |
((word & 0x001fe000) << 3) |
((word & 0x000003fc) << 6);
break;
case 6:
word = *pword + *(pword + 1);
*(lined + j) = ((word & 0x7f800000) << 1) |
((word & 0x000ff000) << 4) |
((word & 0x000001fe) << 7);
break;
case 7:
word = *pword + 2 * (*(pword + 1)) + *(pword + wpls + 1);
*(lined + j) = (word & 0xff000000) |
((word & 0x001fe000) << 3) |
((word & 0x000003fc) << 6);
break;
case 8:
word = *pword + *(pword + wpls);
*(lined + j) = ((word & 0x7f800000) << 1) |
((word & 0x000ff000) << 4) |
((word & 0x000001fe) << 7);
break;
case 9:
word = *pword + *(pword + wpls);
*(lined + j) = ((word & 0x7f800000) << 1) |
((word & 0x000ff000) << 4) |
((word & 0x000001fe) << 7);
break;
case 10:
word = *pword + *(pword + 1) + *(pword + wpls) +
*(pword + wpls + 1);
*(lined + j) = (word & 0xff000000) |
((word & 0x001fe000) << 3) |
((word & 0x000003fc) << 6);
break;
case 11:
word = *(pword + 1) + *(pword + wpls + 1);
*(lined + j) = ((word & 0x7f800000) << 1) |
((word & 0x000ff000) << 4) |
((word & 0x000001fe) << 7);
break;
case 12:
word = *pword + 3 * (*(pword + wpls));
*(lined + j) = (word & 0xff000000) |
((word & 0x001fe000) << 3) |
((word & 0x000003fc) << 6);
break;
case 13:
word = *pword + 2 * (*(pword + wpls)) + *(pword + wpls + 1);
*(lined + j) = (word & 0xff000000) |
((word & 0x001fe000) << 3) |
((word & 0x000003fc) << 6);
break;
case 14:
word = *(pword + wpls) + *(pword + wpls + 1);
*(lined + j) = ((word & 0x7f800000) << 1) |
((word & 0x000ff000) << 4) |
((word & 0x000001fe) << 7);
break;
case 15:
word = *(pword + 1) + *(pword + wpls) +
2 * (*(pword + wpls + 1));
*(lined + j) = (word & 0xff000000) |
((word & 0x001fe000) << 3) |
((word & 0x000003fc) << 6);
break;
default: /* for testing only; no interpolation, no shift */
fprintf(stderr, "shouldn't get here\n");
*(lined + j) = *pword;
break;
}
}
}
return;
}
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