tesseract/ccmain/scaleimg.cpp
2010-05-26 10:22:27 +00:00

371 lines
10 KiB
C++

/**********************************************************************
* File: scaleimg.cpp (Formerly scaleim.c)
* Description: Smart scaling of images.
* Author: Phil Cheatle
* Created: Wed Nov 18 16:12:03 GMT 1992
*
* (C) Copyright 1992, Hewlett-Packard Ltd.
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
** http://www.apache.org/licenses/LICENSE-2.0
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*
**********************************************************************/
/*************************************************************************
* This is really Sheelagh's code that I've hacked into a more usable form.
* You simply call scale_image() passing in source and target images. The target
* image should be empty, but created - in order to define the destination
* size.
*************************************************************************/
#ifdef _MSC_VER
#pragma warning(disable:4244) // Conversion warnings
#endif
#include "mfcpch.h"
#include <stdlib.h>
#include <string.h>
#include "fileerr.h"
#include "tprintf.h"
//#include "grphics.h"
#include "img.h"
//#include "basefile.h"
#include "imgscale.h"
#include "scaleimg.h"
void scale_image( //scale an image
IMAGE &image, //source image
IMAGE &target_image //target image
) {
inT32 xsize, ysize, new_xsize, new_ysize;
IMAGELINE line, new_line;
int *hires, *lores, *oldhires, *oldlores;
int i, j, n, oldn, row, col;
int offset = 0; //not used here
float factor;
uinT8 curr_colour, new_colour;
int dummy = -1;
IMAGE image2; //horiz scaled image
xsize = image.get_xsize ();
ysize = image.get_ysize ();
new_xsize = target_image.get_xsize ();
new_ysize = target_image.get_ysize ();
if (new_ysize > new_xsize)
new_line.init (new_ysize);
else
new_line.init (new_xsize);
factor = (float) xsize / (float) new_xsize;
hires = (int *) calloc (xsize, sizeof (int));
lores = (int *) calloc (new_xsize, sizeof (int));
oldhires = (int *) calloc (xsize, sizeof (int));
oldlores = (int *) calloc (new_xsize, sizeof (int));
if ((hires == NULL) || (lores == NULL) || (oldhires == NULL)
|| (oldlores == NULL)) {
fprintf (stderr, "Calloc error in scale_image\n");
err_exit();
}
image2.create (new_xsize, ysize, image.get_bpp ());
oldn = 0;
/* do first row separately because hires[col-1] doesn't make sense here */
image.fast_get_line (0, 0, xsize, &line);
/* each line nominally begins with white */
curr_colour = 1;
n = 0;
for (i = 0; i < xsize; i++) {
new_colour = *(line.pixels + i);
if (new_colour != curr_colour) {
hires[n] = i;
n++;
curr_colour = new_colour;
}
}
if (offset != 0)
for (i = 0; i < n; i++)
hires[i] += offset;
if (n > new_xsize) {
tprintf ("Too many transitions (%d) on line 0\n", n);
scale_image_cop_out(image,
target_image,
factor,
hires,
lores,
oldhires,
oldlores);
return;
}
else if (n > 0)
dyn_prog (n, hires, lores, new_xsize, &dummy, &dummy, 0, factor);
else
lores[0] = new_xsize;
curr_colour = 1;
j = 0;
for (i = 0; i < new_xsize; i++) {
if (lores[j] == i) {
curr_colour = 1 - curr_colour;
j++;
}
*(new_line.pixels + i) = curr_colour;
}
image2.put_line (0, 0, new_xsize, &new_line, 0);
for (i = 0; i < n; i++) {
oldhires[i] = hires[i];
oldlores[i] = lores[i];
}
for (i = n; i < oldn; i++) {
oldhires[i] = 0;
oldlores[i] = 0;
}
oldn = n;
for (row = 1; row < ysize; row++) {
image.fast_get_line (0, row, xsize, &line);
/* each line nominally begins with white */
curr_colour = 1;
n = 0;
for (i = 0; i < xsize; i++) {
new_colour = *(line.pixels + i);
if (new_colour != curr_colour) {
hires[n] = i;
n++;
curr_colour = new_colour;
}
}
for (i = n; i < oldn; i++) {
hires[i] = 0;
lores[i] = 0;
}
if (offset != 0)
for (i = 0; i < n; i++)
hires[i] += offset;
if (n > new_xsize) {
tprintf ("Too many transitions (%d) on line %d\n", n, row);
scale_image_cop_out(image,
target_image,
factor,
hires,
lores,
oldhires,
oldlores);
return;
}
else if (n > 0)
dyn_prog(n, hires, lores, new_xsize, oldhires, oldlores, oldn, factor);
else
lores[0] = new_xsize;
curr_colour = 1;
j = 0;
for (i = 0; i < new_xsize; i++) {
if (lores[j] == i) {
curr_colour = 1 - curr_colour;
j++;
}
*(new_line.pixels + i) = curr_colour;
}
image2.put_line (0, row, new_xsize, &new_line, 0);
for (i = 0; i < n; i++) {
oldhires[i] = hires[i];
oldlores[i] = lores[i];
}
for (i = n; i < oldn; i++) {
oldhires[i] = 0;
oldlores[i] = 0;
}
oldn = n;
}
free(hires);
free(lores);
free(oldhires);
free(oldlores);
/* NOW DO THE VERTICAL SCALING from image2 to target_image*/
xsize = new_xsize;
factor = (float) ysize / (float) new_ysize;
offset = 0;
hires = (int *) calloc (ysize, sizeof (int));
lores = (int *) calloc (new_ysize, sizeof (int));
oldhires = (int *) calloc (ysize, sizeof (int));
oldlores = (int *) calloc (new_ysize, sizeof (int));
if ((hires == NULL) || (lores == NULL) || (oldhires == NULL)
|| (oldlores == NULL)) {
fprintf (stderr, "Calloc error in scale_image (vert)\n");
err_exit();
}
oldn = 0;
/* do first col separately because hires[col-1] doesn't make sense here */
image2.get_column (0, 0, ysize, &line, 0);
/* each line nominally begins with white */
curr_colour = 1;
n = 0;
for (i = 0; i < ysize; i++) {
new_colour = *(line.pixels + i);
if (new_colour != curr_colour) {
hires[n] = i;
n++;
curr_colour = new_colour;
}
}
if (offset != 0)
for (i = 0; i < n; i++)
hires[i] += offset;
if (n > new_ysize) {
tprintf ("Too many transitions (%d) on column 0\n", n);
scale_image_cop_out(image,
target_image,
factor,
hires,
lores,
oldhires,
oldlores);
return;
}
else if (n > 0)
dyn_prog (n, hires, lores, new_ysize, &dummy, &dummy, 0, factor);
else
lores[0] = new_ysize;
curr_colour = 1;
j = 0;
for (i = 0; i < new_ysize; i++) {
if (lores[j] == i) {
curr_colour = 1 - curr_colour;
j++;
}
*(new_line.pixels + i) = curr_colour;
}
target_image.put_column (0, 0, new_ysize, &new_line, 0);
for (i = 0; i < n; i++) {
oldhires[i] = hires[i];
oldlores[i] = lores[i];
}
for (i = n; i < oldn; i++) {
oldhires[i] = 0;
oldlores[i] = 0;
}
oldn = n;
for (col = 1; col < xsize; col++) {
image2.get_column (col, 0, ysize, &line, 0);
/* each line nominally begins with white */
curr_colour = 1;
n = 0;
for (i = 0; i < ysize; i++) {
new_colour = *(line.pixels + i);
if (new_colour != curr_colour) {
hires[n] = i;
n++;
curr_colour = new_colour;
}
}
for (i = n; i < oldn; i++) {
hires[i] = 0;
lores[i] = 0;
}
if (offset != 0)
for (i = 0; i < n; i++)
hires[i] += offset;
if (n > new_ysize) {
tprintf ("Too many transitions (%d) on column %d\n", n, col);
scale_image_cop_out(image,
target_image,
factor,
hires,
lores,
oldhires,
oldlores);
return;
}
else if (n > 0)
dyn_prog(n, hires, lores, new_ysize, oldhires, oldlores, oldn, factor);
else
lores[0] = new_ysize;
curr_colour = 1;
j = 0;
for (i = 0; i < new_ysize; i++) {
if (lores[j] == i) {
curr_colour = 1 - curr_colour;
j++;
}
*(new_line.pixels + i) = curr_colour;
}
target_image.put_column (col, 0, new_ysize, &new_line, 0);
for (i = 0; i < n; i++) {
oldhires[i] = hires[i];
oldlores[i] = lores[i];
}
for (i = n; i < oldn; i++) {
oldhires[i] = 0;
oldlores[i] = 0;
}
oldn = n;
}
free(hires);
free(lores);
free(oldhires);
free(oldlores);
}
/**********************************************************************
* scale_image_cop_out
*
* Cop-out of scale_image by doing it the easy way and free the data.
**********************************************************************/
void scale_image_cop_out( //scale an image
IMAGE &image, //source image
IMAGE &target_image, //target image
float factor, //scale factor
int *hires,
int *lores,
int *oldhires,
int *oldlores) {
inT32 xsize, ysize, new_xsize, new_ysize;
xsize = image.get_xsize ();
ysize = image.get_ysize ();
new_xsize = target_image.get_xsize ();
new_ysize = target_image.get_ysize ();
if (factor <= 0.5)
reduce_sub_image (&image, 0, 0, xsize, ysize,
&target_image, 0, 0, (inT32) (1.0 / factor), FALSE);
else if (factor >= 2)
enlarge_sub_image (&image, 0, 0, &target_image,
0, 0, new_xsize, new_ysize, (inT32) factor, FALSE);
else
copy_sub_image (&image, 0, 0, xsize, ysize, &target_image, 0, 0, FALSE);
free(hires);
free(lores);
free(oldhires);
free(oldlores);
}