path: root/include/zbar/Image.h

//------------------------------------------------------------------------
//  Copyright 2007-2010 (c) Jeff Brown <spadix@users.sourceforge.net>
//
//  This file is part of the ZBar Bar Code Reader.
//
//  The ZBar Bar Code Reader is free software; you can redistribute it
//  and/or modify it under the terms of the GNU Lesser Public License as
//  published by the Free Software Foundation; either version 2.1 of
//  the License, or (at your option) any later version.
//
//  The ZBar Bar Code Reader is distributed in the hope that it will be
//  useful, but WITHOUT ANY WARRANTY; without even the implied warranty
//  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser Public License for more details.
//
//  You should have received a copy of the GNU Lesser Public License
//  along with the ZBar Bar Code Reader; if not, write to the Free
//  Software Foundation, Inc., 51 Franklin St, Fifth Floor,
//  Boston, MA  02110-1301  USA
//
//  http://sourceforge.net/projects/zbar
//------------------------------------------------------------------------
#ifndef _ZBAR_IMAGE_H_
#define _ZBAR_IMAGE_H_

/// @file
/// Image C++ wrapper

#ifndef _ZBAR_H_
#error "include zbar.h in your application, **not** zbar/Image.h"
#endif

#include <assert.h>
#include <iterator>
#include "Exception.h"
#include "Symbol.h"

namespace zbar
{
class Video;

/// stores image data samples along with associated format and size
/// metadata

class Image
{
public:
    /// general Image result handler.
    /// applications should subtype this and pass an instance to
    /// eg. ImageScanner::set_handler() to implement result processing
    class Handler
    {
    public:
	virtual ~Handler()
	{
	}

	/// invoked by library when Image should be processed
	virtual void image_callback(Image &image) = 0;

	/// cast this handler to the C handler
	operator zbar_image_data_handler_t *() const
	{
	    return (_cb);
	}

    private:
	static void _cb(zbar_image_t *zimg, const void *userdata)
	{
	    if (userdata) {
		Image *image = (Image *)zbar_image_get_userdata(zimg);
		if (image)
		    ((Handler *)userdata)->image_callback(*image);
		else {
		    Image tmp(zimg, 1);
		    ((Handler *)userdata)->image_callback(tmp);
		}
	    }
	}
    };

    class SymbolIterator : public zbar::SymbolIterator
    {
    public:
	/// default constructor.
	SymbolIterator() : zbar::SymbolIterator()
	{
	}

	/// constructor.
	SymbolIterator(const SymbolSet &syms) : zbar::SymbolIterator(syms)
	{
	}

	/// copy constructor.
	SymbolIterator(const SymbolIterator &iter) : zbar::SymbolIterator(iter)
	{
	}
    };

    /// constructor.
    /// create a new Image with the specified parameters
    Image(unsigned width = 0, unsigned height = 0,
	  const std::string &format = "", const void *data = NULL,
	  unsigned long length = 0)
	: _img(zbar_image_create())
    {
	zbar_image_set_userdata(_img, this);
	if (width && height)
	    set_size(width, height);
	if (format.length())
	    set_format(format);
	if (data && length)
	    set_data(data, length);
    }

    ~Image()
    {
	if (zbar_image_get_userdata(_img) == this)
	    zbar_image_set_userdata(_img, NULL);
	zbar_image_ref(_img, -1);
    }

    /// cast to C image object
    operator const zbar_image_t *() const
    {
	return (_img);
    }

    /// cast to C image object
    operator zbar_image_t *()
    {
	return (_img);
    }

    /// retrieve the image format.
    /// see zbar_image_get_format()
    unsigned long get_format() const
    {
	return (zbar_image_get_format(_img));
    }

    /// specify the fourcc image format code for image sample data.
    /// see zbar_image_set_format()
    void set_format(unsigned long format)
    {
	zbar_image_set_format(_img, format);
    }

    /// specify the fourcc image format code for image sample data.
    /// see zbar_image_set_format()
    void set_format(const std::string &format)
    {
	unsigned long fourcc = zbar_fourcc_parse(format.c_str());
	zbar_image_set_format(_img, fourcc);
    }

    /// retrieve a "sequence" (page/frame) number associated with this
    /// image.
    /// see zbar_image_get_sequence()
    /// @since 0.6
    unsigned get_sequence() const
    {
	return (zbar_image_get_sequence(_img));
    }

    /// associate a "sequence" (page/frame) number with this image.
    /// see zbar_image_set_sequence()
    /// @since 0.6
    void set_sequence(unsigned sequence_num)
    {
	zbar_image_set_sequence(_img, sequence_num);
    }

    /// retrieve the width of the image.
    /// see zbar_image_get_width()
    unsigned get_width() const
    {
	return (zbar_image_get_width(_img));
    }

    /// retrieve the height of the image.
    /// see zbar_image_get_height()
    unsigned get_height() const
    {
	return (zbar_image_get_height(_img));
    }

    /// retrieve both dimensions of the image.
    /// see zbar_image_get_size()
    /// @since 0.11
    void get_size(unsigned &width, unsigned &height) const
    {
	zbar_image_get_size(_img, &width, &height);
    }

    /// specify the pixel size of the image.
    /// see zbar_image_set_size()
    void set_size(unsigned width, unsigned height)
    {
	zbar_image_set_size(_img, width, height);
    }

    /// retrieve the scan crop rectangle.
    /// see zbar_image_get_crop()
    void get_crop(unsigned &x, unsigned &y, unsigned &width,
		  unsigned &height) const
    {
	zbar_image_get_crop(_img, &x, &y, &width, &height);
    }

    /// set the scan crop rectangle.
    /// see zbar_image_set_crop()
    void set_crop(unsigned x, unsigned y, unsigned width, unsigned height)
    {
	zbar_image_set_crop(_img, x, y, width, height);
    }

    /// return the image sample data.
    /// see zbar_image_get_data()
    const void *get_data() const
    {
	return (zbar_image_get_data(_img));
    }

    /// return the size of the image sample data.
    /// see zbar_image_get_data_length()
    /// @since 0.6
    unsigned long get_data_length() const
    {
	return (zbar_image_get_data_length(_img));
    }

    /// specify image sample data.
    /// see zbar_image_set_data()
    void set_data(const void *data, unsigned long length)
    {
	zbar_image_set_data(_img, data, length, _cleanup);
    }

    /// image format conversion.
    /// see zbar_image_convert()
    Image convert(unsigned long format) const
    {
	zbar_image_t *img = zbar_image_convert(_img, format);
	if (img)
	    return (Image(img));
	throw FormatError();
    }

    /// image format conversion.
    /// see zbar_image_convert()
    /// @since 0.11
    Image convert(std::string format) const
    {
	unsigned long fourcc = zbar_fourcc_parse(format.c_str());
	return (convert(fourcc));
    }

    /// image format conversion with crop/pad.
    /// see zbar_image_convert_resize()
    /// @since 0.4
    Image convert(unsigned long format, unsigned width, unsigned height) const
    {
	zbar_image_t *img;

	img = zbar_image_convert_resize(_img, format, width, height);
	if (img)
	    return (Image(img));
	throw FormatError();
    }

    const SymbolSet get_symbols() const
    {
	return (SymbolSet(zbar_image_get_symbols(_img)));
    }

    void set_symbols(const SymbolSet &syms)
    {
	zbar_image_set_symbols(_img, syms);
    }

    /// create a new SymbolIterator over decoded results.
    SymbolIterator symbol_begin() const
    {
	return (SymbolIterator(get_symbols()));
    }

    /// return a SymbolIterator suitable for ending iteration.
    SymbolIterator symbol_end() const
    {
	return (SymbolIterator());
    }

protected:
    friend class Video;

    /// constructor.
    /// @internal
    /// create a new Image from a zbar_image_t C object
    Image(zbar_image_t *src, int refs = 0) : _img(src)
    {
	if (refs)
	    zbar_image_ref(_img, refs);
	zbar_image_set_userdata(_img, this);
    }

    /// default data cleanup (noop)
    /// @internal
    static void _cleanup(zbar_image_t *img)
    {
	// by default nothing is cleaned
	assert(img);
    }

private:
    zbar_image_t *_img;
};

} // namespace zbar

#endif