You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
321 lines
13 KiB
321 lines
13 KiB
//C- -------------------------------------------------------------------
|
|
//C- DjVuLibre-3.5
|
|
//C- Copyright (c) 2002 Leon Bottou and Yann Le Cun.
|
|
//C- Copyright (c) 2001 AT&T
|
|
//C-
|
|
//C- This software is subject to, and may be distributed under, the
|
|
//C- GNU General Public License, Version 2. The license should have
|
|
//C- accompanied the software or you may obtain a copy of the license
|
|
//C- from the Free Software Foundation at http://www.fsf.org .
|
|
//C-
|
|
//C- This program is distributed in the hope that it will be useful,
|
|
//C- but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
//C- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
//C- GNU General Public License for more details.
|
|
//C-
|
|
//C- DjVuLibre-3.5 is derived from the DjVu(r) Reference Library
|
|
//C- distributed by Lizardtech Software. On July 19th 2002, Lizardtech
|
|
//C- Software authorized us to replace the original DjVu(r) Reference
|
|
//C- Library notice by the following text (see doc/lizard2002.djvu):
|
|
//C-
|
|
//C- ------------------------------------------------------------------
|
|
//C- | DjVu (r) Reference Library (v. 3.5)
|
|
//C- | Copyright (c) 1999-2001 LizardTech, Inc. All Rights Reserved.
|
|
//C- | The DjVu Reference Library is protected by U.S. Pat. No.
|
|
//C- | 6,058,214 and patents pending.
|
|
//C- |
|
|
//C- | This software is subject to, and may be distributed under, the
|
|
//C- | GNU General Public License, Version 2. The license should have
|
|
//C- | accompanied the software or you may obtain a copy of the license
|
|
//C- | from the Free Software Foundation at http://www.fsf.org .
|
|
//C- |
|
|
//C- | The computer code originally released by LizardTech under this
|
|
//C- | license and unmodified by other parties is deemed "the LIZARDTECH
|
|
//C- | ORIGINAL CODE." Subject to any third party intellectual property
|
|
//C- | claims, LizardTech grants recipient a worldwide, royalty-free,
|
|
//C- | non-exclusive license to make, use, sell, or otherwise dispose of
|
|
//C- | the LIZARDTECH ORIGINAL CODE or of programs derived from the
|
|
//C- | LIZARDTECH ORIGINAL CODE in compliance with the terms of the GNU
|
|
//C- | General Public License. This grant only confers the right to
|
|
//C- | infringe patent claims underlying the LIZARDTECH ORIGINAL CODE to
|
|
//C- | the extent such infringement is reasonably necessary to enable
|
|
//C- | recipient to make, have made, practice, sell, or otherwise dispose
|
|
//C- | of the LIZARDTECH ORIGINAL CODE (or portions thereof) and not to
|
|
//C- | any greater extent that may be necessary to utilize further
|
|
//C- | modifications or combinations.
|
|
//C- |
|
|
//C- | The LIZARDTECH ORIGINAL CODE is provided "AS IS" WITHOUT WARRANTY
|
|
//C- | OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
|
|
//C- | TO ANY WARRANTY OF NON-INFRINGEMENT, OR ANY IMPLIED WARRANTY OF
|
|
//C- | MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
|
|
//C- +------------------------------------------------------------------
|
|
//
|
|
// $Id: GScaler.h,v 1.9 2003/11/07 22:08:21 leonb Exp $
|
|
// $Name: release_3_5_15 $
|
|
|
|
#ifndef _GSCALER_H_
|
|
#define _GSCALER_H_
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
#if NEED_GNUG_PRAGMAS
|
|
# pragma interface
|
|
#endif
|
|
|
|
// From: Leon Bottou, 1/31/2002
|
|
// Almost equal to my initial code.
|
|
|
|
#include "GException.h"
|
|
#include "GRect.h"
|
|
#include "GBitmap.h"
|
|
#include "GPixmap.h"
|
|
|
|
#ifdef HAVE_NAMESPACES
|
|
namespace DJVU {
|
|
# ifdef NOT_DEFINED // Just to fool emacs c++ mode
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
|
|
/** @name GScaler.h
|
|
|
|
Files #"GScaler.h"# and #"GScaler.cpp"# implement a fast bilinear
|
|
interpolation scheme to rescale a \Ref{GBitmap} or a \Ref{GPixmap}.
|
|
Common setup functions are implemented by the base class \Ref{GScaler}.
|
|
The actual function for rescaling a gray level image is implemented by
|
|
class \Ref{GBitmapScaler}. The actual function for rescaling a color
|
|
image is implemented by class \Ref{GPixmapScaler}.
|
|
|
|
{\bf Remark} --- The bilinear interpolation code relies on fixed precision
|
|
tables. It becomes suboptimal when upsampling (i.e. zooming into) an
|
|
image by a factor greater than eight. High contrast images displayed at
|
|
high magnification may contain visible jaggies.
|
|
|
|
@memo
|
|
Rescaling images with bilinear interpolation.
|
|
@author
|
|
L\'eon Bottou <leonb@research.att.com>
|
|
@version
|
|
#$Id: GScaler.h,v 1.9 2003/11/07 22:08:21 leonb Exp $# */
|
|
//@{
|
|
|
|
|
|
/** Base class for GBitmapScaler and GPixmapScaler. This base class
|
|
implements the common elements of class \Ref{GBitmapScaler} and
|
|
\Ref{GPixmapScaler}. Functions \Ref{set_input_size} and
|
|
\Ref{set_output_size} are used to specify the size of the input image and
|
|
the size of the output image. Functions \Ref{set_horz_ratio} and
|
|
\Ref{set_vert_ratio} may be used to override the scaling ratios computed
|
|
from the image sizes. You can then call function \Ref{get_input_rect} to
|
|
know which pixels of the input image are necessary to compute a specified
|
|
rectangular zone of the output image. The actual computation is then
|
|
performed by calling function #scale# in class \Ref{GBitmapScaler} and
|
|
\Ref{GPixmapScaler}.
|
|
*/
|
|
class GScaler : public GPEnabled
|
|
{
|
|
protected:
|
|
GScaler();
|
|
public:
|
|
virtual ~GScaler();
|
|
/** Sets the size of the input image. Argument #w# (resp. #h#) contains the
|
|
horizontal (resp. vertical) size of the input image. This size is used
|
|
to initialize the internal data structures of the scaler object. */
|
|
void set_input_size(int w, int h);
|
|
/** Sets the size of the output image. Argument #w# (resp. #h#) contains the
|
|
horizontal (resp. vertical) size of the output image. This size is used
|
|
to initialize the internal data structures of the scaler object. */
|
|
void set_output_size(int w, int h);
|
|
/** Sets the horizontal scaling ratio #numer/denom#. This function may be
|
|
used to force an exact scaling ratio. The scaling ratios are otherwise
|
|
derived from the sizes of the input and output images. */
|
|
void set_horz_ratio(int numer, int denom);
|
|
/** Sets the vertical scaling ratio to #numer/denom#. This function may be
|
|
used to force an exact scaling ratio. The scaling ratios are otherwise
|
|
derived from the sizes of the input and output images. */
|
|
void set_vert_ratio(int numer, int denom);
|
|
/** Computes which input pixels are required to compute specified output
|
|
pixels. Let us assume that we only need a part of the output
|
|
image. This part is defined by rectangle #desired_output#. Only a part
|
|
of the input image is necessary to compute the output pixels. Function
|
|
#get_input_rect# computes the coordinates of that part of the input
|
|
image, and stores them into rectangle #required_input#. */
|
|
void get_input_rect( const GRect &desired_output, GRect &required_input );
|
|
protected:
|
|
// The sizes
|
|
int inw, inh;
|
|
int xshift, yshift;
|
|
int redw, redh;
|
|
int outw, outh;
|
|
// Fixed point coordinates
|
|
int *vcoord;
|
|
GPBuffer<int> gvcoord;
|
|
int *hcoord;
|
|
GPBuffer<int> ghcoord;
|
|
// Helper
|
|
void make_rectangles(const GRect &desired, GRect &red, GRect &inp);
|
|
};
|
|
|
|
|
|
|
|
/** Fast rescaling code for gray level images. This class augments the base
|
|
class \Ref{GScaler} with a function for rescaling gray level
|
|
images. Function \Ref{GBitmapScaler::scale} computes an arbitrary segment
|
|
of the output image given the corresponding pixels in the input image.
|
|
|
|
{\bf Example} --- The following functions returns an gray level image
|
|
(sixteen gray levels, size #nw# by #nh#) containing a rescaled version of
|
|
the input image #in#.
|
|
\begin{verbatim}
|
|
GBitmap *rescale_bitmap(const GBitmap &in, int nw, int nh)
|
|
{
|
|
int w = in.columns(); // Get input width
|
|
int h = in.raws(); // Get output width
|
|
GBitmapScaler scaler(w,h,nw,nh); // Creates bitmap scaler
|
|
GRect desired(0,0,nw,nh); // Desired output = complete bitmap
|
|
GRect provided(0,0,w,h); // Provided input = complete bitmap
|
|
GBitmap *out = new GBitmap;
|
|
scaler.scale(provided, in, desired, *out); // Rescale
|
|
out->change_grays(16); // Reduce to 16 gray levels
|
|
return out;
|
|
}
|
|
\end{verbatim} */
|
|
class GBitmapScaler : public GScaler
|
|
{
|
|
protected:
|
|
GBitmapScaler(void);
|
|
GBitmapScaler(int inw, int inh, int outw, int outh);
|
|
public:
|
|
/// Virtual destructor.
|
|
virtual ~GBitmapScaler();
|
|
|
|
/** Creates an empty GBitmapScaler. You must call functions
|
|
\Ref{GScaler::set_input_size} and \Ref{GScaler::set_output_size} before
|
|
calling any of the scaling functions. */
|
|
static GP<GBitmapScaler> create(void) {return new GBitmapScaler(); }
|
|
|
|
/** Creates a GBitmapScaler. The size of the input image is given by
|
|
#inw# and #inh#. This function internally calls
|
|
\Ref{GScaler::set_input_size} and \Ref{GScaler::set_output_size}. The
|
|
size of the output image is given by #outw# and #outh#. . */
|
|
static GP<GBitmapScaler> create(
|
|
const int inw, const int inh, const int outw, const int outh)
|
|
{ return new GBitmapScaler(inw,inh,outw,outh); }
|
|
|
|
/** Computes a segment of the rescaled output image. The GBitmap object
|
|
#output# is overwritten with the segment of the output image specified
|
|
by the rectangle #desired_output#. The rectangle #provided_input#
|
|
specifies which segment of the input image is provided by the GBitmap
|
|
object #input#. An exception \Ref{GException} is thrown if the
|
|
rectangle #provided_input# is smaller then the rectangle
|
|
#required_input# returned by function \Ref{GScaler::get_input_rect}.
|
|
Note that the output image always contain 256 gray levels. You may want
|
|
to use function \Ref{GBitmap::change_grays} to reduce the number of gray
|
|
levels. */
|
|
void scale( const GRect &provided_input, const GBitmap &input,
|
|
const GRect &desired_output, GBitmap &output );
|
|
protected:
|
|
// Helpers
|
|
unsigned char *get_line(int, const GRect &, const GRect &, const GBitmap &);
|
|
// Temporaries
|
|
unsigned char *lbuffer;
|
|
GPBuffer<unsigned char> glbuffer;
|
|
unsigned char *conv;
|
|
GPBuffer<unsigned char> gconv;
|
|
unsigned char *p1;
|
|
GPBuffer<unsigned char> gp1;
|
|
unsigned char *p2;
|
|
GPBuffer<unsigned char> gp2;
|
|
int l1;
|
|
int l2;
|
|
};
|
|
|
|
|
|
/** Fast rescaling code for color images. This class augments the base class
|
|
\Ref{GScaler} with a function for rescaling color images. Function
|
|
\Ref{GPixmapScaler::scale} computes an arbitrary segment of the output
|
|
image given the corresponding pixels in the input image.
|
|
|
|
{\bf Example} --- The following functions returns a color image
|
|
of size #nw# by #nh# containing a rescaled version of
|
|
the input image #in#.
|
|
\begin{verbatim}
|
|
GPixmap *rescale_pixmap(const GPixmap &in, int nw, int nh)
|
|
{
|
|
int w = in.columns(); // Get input width
|
|
int h = in.raws(); // Get output width
|
|
GPixmapScaler scaler(w,h,nw,nh); // Creates bitmap scaler
|
|
GRect desired(0,0,nw,nh); // Desired output = complete image
|
|
GRect provided(0,0,w,h); // Provided input = complete image
|
|
GPixmap *out = new GPixmap;
|
|
scaler.scale(provided, in, desired, *out); // Rescale
|
|
return out;
|
|
}
|
|
\end{verbatim}
|
|
|
|
*/
|
|
class GPixmapScaler : public GScaler
|
|
{
|
|
protected:
|
|
GPixmapScaler(void);
|
|
GPixmapScaler(int inw, int inh, int outw, int outh);
|
|
public:
|
|
/// Virtual destructor.
|
|
virtual ~GPixmapScaler();
|
|
|
|
/** Creates an empty GPixmapScaler. You must call functions
|
|
\Ref{GScaler::set_input_size} and \Ref{GScaler::set_output_size} before
|
|
calling any of the scaling functions. */
|
|
static GP<GPixmapScaler> create(void) {return new GPixmapScaler(); }
|
|
|
|
/** Creates a GPixmapScaler. The size of the input image is given by
|
|
#inw# and #inh#. This function internally calls
|
|
\Ref{GScaler::set_input_size} and \Ref{GScaler::set_output_size}. The
|
|
size of the output image is given by #outw# and #outh#. . */
|
|
static GP<GPixmapScaler> create(
|
|
const int inw, const int inh, const int outw, const int outh)
|
|
{ return new GPixmapScaler(inw,inh,outw,outh); }
|
|
|
|
/** Computes a segment of the rescaled output image. The pixmap #output# is
|
|
overwritten with the segment of the output image specified by the
|
|
rectangle #desired_output#. The rectangle #provided_input# specifies
|
|
which segment of the input image is provided in the pixmap #input#. An
|
|
exception \Ref{GException} is thrown if the rectangle #provided_input#
|
|
is smaller then the rectangle #required_input# returned by function
|
|
\Ref{GScaler::get_input_rect}. */
|
|
void scale( const GRect &provided_input, const GPixmap &input,
|
|
const GRect &desired_output, GPixmap &output );
|
|
protected:
|
|
// Helpers
|
|
GPixel *get_line(int, const GRect &, const GRect &, const GPixmap &);
|
|
// Temporaries
|
|
GPixel *lbuffer;
|
|
GPBufferBase glbuffer;
|
|
GPixel *p1;
|
|
GPBufferBase gp1;
|
|
GPixel *p2;
|
|
GPBufferBase gp2;
|
|
int l1;
|
|
int l2;
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
//@}
|
|
|
|
|
|
|
|
|
|
// -------- END
|
|
|
|
#ifdef HAVE_NAMESPACES
|
|
}
|
|
# ifndef NOT_USING_DJVU_NAMESPACE
|
|
using namespace DJVU;
|
|
# endif
|
|
#endif
|
|
#endif
|