I still think it was a good idea, and it worked, but.... why not make it simple. KISS, Keep It Simple (Stupid!). I guess this pseudo-class design was a consequence of the previous codebase, and I used code tricks instead of imagination.

So, after a midnight revelation (yes, around 03:00, in bed...) and a few days rewriting (again...), the design is now simple, very simple:

new image design

The image definition is:

/**
 * generic image structure
 */
typedef struct s_image
{
/* TODO : add bit depth and channels */
     mw_dtype dtype;   /**< datatype of the stored values */
     uint16 ncol;      /**< number of columns */
     uint16 nrow;      /**< number of rows    */
     void * data;      /**< data array        */
} mw_image;

Yes, that's it. An image is:

• a data type (an integer, in fact, but users should only use MW_DT_XX macros)
• a number of rows
• a number or columns
• a data array

Later, we may introduce some other structure fields, if they are needed my many algorithms; but the best way could be to add a simple generic pointer, and let everyone use it as they like (or even register some alloc/dealloc/copy routines).

For color images, the idea is to add a uint8 nchn field for the number of channels; then, we have the following correspondances:

• 1 channel : grayscale image
• 2 channels : grayscale+alpha image
• 3 channels : RGB image
• 4 channels : RGB+alpha image

But it still is possible to define a 255 channels images, if it makes sense (for the algo and for the memory space).

user interface

This generic data array can be used in different ways:

• high-level, generic
  With the macro XY(img, x, y), you access the same point, but through less function calls, so it's faster. As it's in fact three nested ( ? : ) operations (to adapt the behaviour to the type), you can't use it as a lvalue, ie to update a value.
• high-level, specific
  For lvalues, or when you know for sure what's the dtype of your image, U8_XY(img, x, y), U16_XY(img, x, y), F32_XY(img, x, y) will work, but still at the cost of two indirections, one sum and one product.
• high-level
  With mw_image_getdot(img, x, y) and mw_image_setdot(img, x, y, value), you can access and update the point (x, y) in the img image. The functions take care of type casting and array position. This is easy, simple, but won't be very fast.
• lower-level In loops, when speed matters, you can still use a classic array syntax. But you will need to know the type used in the data array, and use type casting because it's not possible to use void pointers directly. It will have to look like ((uint8 *) image->data)[y * ncol + x], but you can also define first data = (uint8 *) image->data, then write data[y * ncol + x]. This also means that you wil need a switch () statement, to select between the possible types.
• lowest-level As usual, in C, lowers-level means pointers. Here also, if you cast image->data to the correct pointer type, everything is fine.

Some profiling is planned, to provide comparative measures of the performance of these levels.

code architecture

This change improves the code architecture, function calls, and dependencies. Now it's possible to implement generic image-processing algorithms without the hassle of dealing with subtypes, unions, and so on. The image file (TXT, PNG, tIFF...) read/write routines are also simplified:

fast loops

By the way, the images are stored by rows, X-style ((0, 0) is the upper-left corner). So, the efficient way to pass through all the pixels is:

uint8 * data;
uint16 nrow, ncol;

data = (uint8 *) image->data;
nrow = data->nrow;
ncol = data->ncol;
for (y = 0; y < nrow; y++)
    for (x = 0; x < ncol; x++)
        do_stuff_with(data[y * ncol + x]);

This ensures a better memory localisation, less CPU cache miss, ... a faster code.

If performance is a matter, pointer arithmetics will save one sum, one product, some tests and some registers at each loop, but the code will be a bit obfuscated:

uint8 * ptr, * stop;

ptr = (uint8 *) image->data;
stop = ptr + image->ncol * image->nrow;
while (ptr < stop)
    do_stuff_with((* ptr++));

• megawave@math-info.univ-paris5.fr
  This list is an open discussion list, for the megawage community: users and developpers are wecome to share their questions, knowledge, ideas.
• megawave-info@math-info.univ-paris5.fr
  This list is an read-only low-traffic list; new releases, meetings and events will be announced here.

To subscribe to these lists, visit their web pages or send a mail to sympa@math-info.univ-paris5.fr with sub megawave or sub megawave-info as the title. The subscription is open; the archives are publicly available.

• mwplight : the light preprocessor
• lib : the megawave kernel and library
• modules : all the modules

This documentation, with tons of exhaustive cross-references, includes

• all the source code, syntax-highlighted
• all the structures, with the structures members
• all the global variables and macros
• all the file inclusion graphs
• all the function call graphs

It is available as

• html, browsable online
• html, archived for download and offline use
• pdf, for printing

Note that the pdf documentation is huge with lots of details and hundredth of pages. I don't think it's worth printing; but il includes pdf hyperlinks for easy navigation. The best way to use this doc is the html format.

type definition, in [[mw3f kernel/lib/include/cimage.h]] :

typedef struct cimage {
  int nrow;
  int ncol;
  int allocsize;
  unsigned char *gray;    
  float scale;
  char cmt[mw_cmtsize];
  char name[mw_namesize];

  int firstcol;
  int lastcol;
  int firstrow;
  int lastrow;

  struct cimage *previous;
  struct cimage *next;
} *Cimage;

• nrow : number of rows (dy)
• ncol : number of columns (dx)
• allocsize : size allocated (in bytes) for the gray plane
• gray : the gray level plane (may be NULL)
• scale : scale of the picture (should be 1 for original pict.)
• cmt : comments
• name : name of the image
• firstcol : index of the first col not affected by left side effect
• lastcol : index of the last col not affected by right side effect
• firstrow : index of the first col not aff. by upper side effect
• lastrow : index of the first col not aff. by lower side effect
• previous : pointer to the previous image (may be NULL)
• next : pointer to the next image (may be NULL)

ccimage

type definition, in [[mw3f kernel/lib/include/ccimage.h]] :

typedef struct ccimage {
  int nrow;
  int ncol;
  int allocsize;
  unsigned char *red;    
  unsigned char *green;    
  unsigned char *blue;    
  float scale;
  char cmt[mw_cmtsize];
  char name[mw_namesize];

  int firstcol;
  int lastcol;
  int firstrow;
  int lastrow;

  struct ccimage *previous;
  struct ccimage *next;
} *Ccimage;

• nrow : number of rows (dy)
• ncol : number of columns (dx)
• allocsize : size allocated (in bytes) for the gray plane
• red : the red level plane (may be NULL)
• green : the green level plane (may be NULL)
• blue : the blue level plane (may be NULL)
• scale : scale of the picture (should be 1 for original pict.)
• cmt : comments
• name : name of the image
• firstcol : index of the first col not affected by left side effect
• lastcol : index of the last col not affected by right side effect
• firstrow : index of the first col not aff. by upper side effect
• lastrow : index of the first col not aff. by lower side effect
• previous : pointer to the previous image (may be NULL)
• next : pointer to the next image (may be NULL)

images and movies

• [[mw3f kernel/lib/src/cimage.c]] : 8bit gray image
• [[mw3f kernel/lib/src/ccimage.c]] : 8bit color image
• [[mw3f kernel/lib/src/fimage.c]] : float gray image
• [[mw3f kernel/lib/src/cfimage.c]] : float color image
• [[mw3f kernel/lib/src/cmovie.c]] : 8bit gray movie
• [[mw3f kernel/lib/src/ccmovie.c]] : 8bit color movie
• [[mw3f kernel/lib/src/fmovie.c]] : float color movie
• [[mw3f kernel/lib/src/cfmovie.c]] : float color movie
• [[mw3f kernel/lib/src/mimage.c]] : morpho gray image
• [[mw3f kernel/lib/src/cmimage.c]] : morpho color image

curves, polygons

• [[mw3f kernel/lib/src/curve.c]] : polygonal lines with integer coordinates
• [[mw3f kernel/lib/src/fcurve.c]] : polygonal lines with float coordinates
• [[mw3f kernel/lib/src/dcurve.c]] : polygonal lines with double float coordinates
• [[mw3f kernel/lib/src/polygon.c]] : polygons with integer coordinates
• [[mw3f kernel/lib/src/fpolygon.c]] : polygons with float coordinates
• [[mw3f kernel/lib/src/shape.c]] : shape structures for the flst

signal and wavelets

• [[mw3f kernel/lib/src/wmax2d.c]] : wavelet maxima structure
• [[mw3f kernel/lib/src/wpack2d.c]] : wavelet pack structure
• [[mw3f kernel/lib/src/wtrans1d.c]] : wavelet trans 1D structure
• [[mw3f kernel/lib/src/wtrans2d.c]] : wavelet trans 2D structure
• [[mw3f kernel/lib/src/fsignal.c]] : fload based signal structure

misc

• [[mw3f kernel/lib/src/list.c]] : float/double list and list of lists structures
• [[mw3f kernel/lib/src/rawdata.c]] : polyvalent rawdata format

custom types i/o

images and movies

• [[mw3f kernel/lib/src/cimage_io.c]] : wrappers for various formats i/o
• [[mw3f kernel/lib/src/ccimage_io.c]] : wrappers for various formats i/o
• [[mw3f kernel/lib/src/fimage_io.c]] : wrappers for various formats i/o
• [[mw3f kernel/lib/src/cfimage_io.c]] : wrappers for various formats i/o
• [[mw3f kernel/lib/src/cmovie_io.c]] : native cmovie format i/o
• [[mw3f kernel/lib/src/ccmovie_io.c]] : native ccmovie format i/o
• [[mw3f kernel/lib/src/fmovie_io.c]] : native fmovie format i/o
• [[mw3f kernel/lib/src/cfmovie_io.c]] : native cfmovie format i/o
• [[mw3f kernel/lib/src/mimage_io.c]] : native mimage format i/o
• [[mw3f kernel/lib/src/cmimage_io.c]] : native cmimage format i/o

curves, polygons

• [[mw3f kernel/lib/src/curve_io.c]] : native curve format i/o
• [[mw3f kernel/lib/src/fcurve_io.c]] : native fcurve format i/o
• [[mw3f kernel/lib/src/dcurve_io.c]] : native dcurve format i/o
• [[mw3f kernel/lib/src/polygon_io.c]] : native polygon format i/o
• [[mw3f kernel/lib/src/fpolygon_io.c]] : native fpolyvgon format i/o
• [[mw3f kernel/lib/src/shape_io.c]] : native shape format i/o

signals and wavelets

• [[mw3f kernel/lib/src/wmax2d_io.c]] : wavelet maxima i/o routines
• [[mw3f kernel/lib/src/wpack2d_io.c]] : wavelet pack i/o routines
• [[mw3f kernel/lib/src/wtrans1d_io.c]] : wavelet trans 1D i/o routines
• [[mw3f kernel/lib/src/wtrans2d_io.c]] : wavelet trans 2D i/o routines
• [[mw3f kernel/lib/src/fsignal_io.c]] : float signal i/o routines

misc

• [[mw3f kernel/lib/src/list_io.c]] : native list formats i/o
• [[mw3f kernel/lib/src/rawdata_io.c]] : native rawdata i/o

external standard formats i/o

• [[mw3f kernel/lib/src/bmp_io.c]] : Microsoft BitMap format
• [[mw3f kernel/lib/src/gif_io.c]] : Graphics Interchange fromat
• [[mw3f kernel/lib/src/img_io.c]] : IMG format
• [[mw3f kernel/lib/src/jpeg_io.c]] : Joint Picture Experts Group format
• [[mw3f kernel/lib/src/pgm_io.c]] : Portable GrayMap format
• [[mw3f kernel/lib/src/pm_io.c]] : Portable BitMap format
• [[mw3f kernel/lib/src/ppm_io.c]] : Portable PixMap format
• [[mw3f kernel/lib/src/tiff_io.c]] : Tagged Image File Format
• [[mw3f kernel/lib/src/notiff.c]] : placeholder if libtiff is not available
• [[mw3f kernel/lib/src/epsf_io.c]] : Encapsulated PostScript file format
• [[mw3f kernel/lib/src/ps_io.c]] : PostScript format
• [[mw3f kernel/lib/src/rim_io.c]] : RIM format
• [[mw3f kernel/lib/src/wave_io.c]] : Waveform Audio format

core

• [[mw3f kernel/lib/src/mw.c]] : various general-purpose functions
• [[mw3f kernel/lib/src/mw_main.c]] : main executable
• [[mw3f kernel/lib/src/mwio.c]] : external file formats i/o wrappers
• [[mw3f kernel/lib/src/module.c]] : module structure
• [[mw3f kernel/lib/src/module_io.c]] : module text descriptions i/o

utilities

• [[mw3f kernel/lib/src/ascii_file.c]] : utilities for manipulating text files
• [[mw3f kernel/lib/src/basic_conv.c]] : conversion routines between native formats
• [[mw3f kernel/lib/src/file_type.c]] : file format recognition
• [[mw3f kernel/lib/src/maketypeconv.c]] : build many-to-many format conversion routines using the existing ones
• [[mw3f kernel/lib/src/type_conv.c]] : automatically generated generic format conversion routines
• [[mw3f kernel/lib/src/unix_bsd.c]] : compatibility layer for BSD/UNIX

X system

• [[mw3f kernel/lib/src/window.c]] : connexion between megawave and the Wdevice X library
• [[mw3f kernel/lib/src/wpanel.c]] : X display custom toolkit
• [[mw3f kernel/lib/src/xmw_com.c]] : connexion between megawave and Xmegawave

Usage: mwplight [options] filename
Options:
  -a, --afile file    name of the A-file (main function of the run-time)
  -m, --mfile file    name of the M-file (source of the modified module)
  -t, --tfile file    name of the T-file (source of the module documentation)
  -i, --ifile file    name of the I-file (interface file for an interpretor)
  -n, --nfile file    name of the N-file (group and name of the module)
  -g, --group group   group the module belongs to (defaults to "unknown")
  -v, --version       print version information
  -d, --debug         debug flag
  -h, -?, --help      print usage help

  -a and -m options and the filename are required.

And no more environment variable is needed.

• [[mw3f Install]]
  build and install script
• [[mw3d data]]
  various data samples
• [[mw3d doc]]
  PDF/DVI versions of the guidebook volume 1 and 2; BibTeX bibliography
  • [[mw3d doc/src]]
    LaTeX documentation for each modules
• [[mw3d kernel]]
  megawave kernel (parser and libs)
  • [[mw3d kernel/mwp]]
    the megawave preprocessor
  • [[mw3d kernel/mwplight]]
    the megawave preprocessor, light version
  • [[mw3d kernel/lib]]
    kernel libraries
    • [[mw3d kernel/lib/src]] kernel libraries source
    • [[mw3d kernel/lib/include]] kernel libraries headers
      • [[mw3d kernel/lib/include/Linux]] custom (ANSI C) Linux headers
      • [[mw3d kernel/lib/include/Solaris]] custom (ANSI C) Solaris headers
  • [[mw3d kernel/shell]]
    various shell helper scripts
    • [[mw3d kernel/shell data]] file fragments for the preprocessor and interformat converters
  • [[mw3d kernel/Wdevice]]
    GUI lib
• [[mw3d src]]
  modules, and a partial module testsuite
  • [[mw3d src/compression]]
  • [[mw3d src/curve]]
  • [[mw3d src/examples]]
  • [[mw3d src/image]]
  • [[mw3d src/signal]]
  • [[mw3d src/wave]]
    mixed topical C modules codes and shell helper scripts

build sequence, megawave v3

• [[mw3f Install]]
  • [[mw3f kernel/shell/mwinstall]]
    • [[mw3f kernel/shell/mwsetenv]]
    • [[mw3f kernel/Install]]
      • [[mw3f kernel/Wdevice/Install]]
        • [[mw3f kernel/shell/mwconfig]]
        • make install
      • [[mw3f kernel/lib/Install]]
        • [[mw3f kernel/shell/mwconfig]]
        • make install
      • [[mw3f kernel/mwp/Install]]
        • [[mw3f kernel/shell/mwconfig]]
        • make install
      • [[mw3f kernel/mwplight/Install]]
        • [[mw3f kernel/shell/mwconfig]]
        • make install
      • make install
    • [[mw3f kernel/shell/cmw2_all]]
      • [[mw3f kernel/shell/cmw2]]
      • mwplight
      • cc/ar/ld
    • [[mw3f kernel/shell/mwmakedoc]]
    • cat
    • latex
    • latex2html
    • [[mw3f kernel/shell/mwmodlist]]
    • [[mw3f kernel/shell/mwmodinstall]]
    • [[mw3f src/Checkmodules]]

compilation and installation

• [[mw3f kernel/shell/mwinstall]] : install megawave
• [[mw3f kernel/shell/mwconfig]] : build a makefile from Makefile.in
• [[mw3f kernel/shell/cmw2]] : compilation of a module or macro
• [[mw3f kernel/shell/cmw2macro]] : compilation of a macro
• [[mw3f kernel/shell/cmw2_all]] : recursive compilation of the modules
• [[mw3f kernel/shell/cxmw2]] : compilation of an X binary
• [[mw3f kernel/shell/cxmw2debug]] : debug version of cmw2
• [[mw3f kernel/shell/mwcleandistrib]] : remove the temporary build files

documentation

• [[mw3f kernel/shell/mwcontrib]] : list the contributors of a modules or macro
• [[mw3f kernel/shell/mwcontrib_all]] : list the contributors of the modules or macro
• [[mw3f kernel/shell/mwdep]] : build a dependencies list for the documentation
• [[mw3f kernel/shell/mwdoc]] : enter the internal documentation system
• [[mw3f kernel/shell/mwdoclatex]] : build the documentation for a module
• [[mw3f kernel/shell/mwdocxdvi]] : display the documentation of a module
• [[mw3f kernel/shell/mwmakedoc]] : make a new updated version of the documentation
• [[mw3f kernel/shell/mwmodbibtex]] : run bibtex on the documentation

modules administration

• [[mw3f kernel/shell/mwmodcheck]] : check the consistency of a preprocessed module source
• [[mw3f kernel/shell/mwmodinstall]] : install a new modules set
• [[mw3f kernel/shell/mwmodlist]] : list the modulkes and macros
• [[mw3f kernel/shell/mwmodsearch]] : search for a module matching words
• [[mw3f kernel/shell/mwnewuser]] : create a directory hierarchy for a new user
• [[mw3f kernel/shell/mwrm]] : remove a module or macro
• [[mw3f src/Checkmodules]] : run some validity tests on some modules

utilities

• [[mw3f kernel/shell/mwarch]] : determine the host archiitecture
• [[mw3f kernel/shell/.mw2helplg_com]] : error handler for the other system scripts
• [[mw3f kernel/shell/mwsetenv]] : set up the environment for megawave (shell environment variables)
• [[mw3f kernel/shell/mwsysmaclist]] : list the system macros
• [[mw3f kernel/shell/mwecho]] : portable [[mw3f echo]]
• [[mw3f kernel/shell/mwisupper]] : is the first letter upper or lower case?
• [[mw3f kernel/shell/mwincvers]] : increment the version number
• [[mw3f kernel/shell/mwvers]] : megawave version number
• [[mw3f kernel/shell/mwwhere]] : tell where the module is
• [[mw3f kernel/shell/mwrnauthor]] : rename an author of a module

user scripts

wavelet compression

• [[mw3f src/compression/ezwave/Cfezw]] : options handler for color EZW compression
• [[mw3f src/compression/ezwave/Fezw]] : options handler for EZW compression
• [[mw3f src/compression/vqwave/Cfwivq]] : options handler for color wavelet decompression
• [[mw3f src/compression/vqwave/Cfwvq]] : options handler for color wavelet compression
• [[mw3f src/compression/vqwave/Fwivq]] : options handler for color wavelet decompression
• [[mw3f src/compression/vqwave/Fwlbg_adap]] : build a codebook for wavelet transformation
• [[mw3f src/compression/vqwave/Fwvq]] : options handler for color wavelet compression

shape recognition

• [[mw3f src/image/shaperecognition/CLEARBASE]] : clear the shape recognition directory
• [[mw3f src/image/shaperecognition/PUTTO_BASE]] : put an image in the shape recognition directory
• [[mw3f src/image/shaperecognition/READBASE]] : show infos about the shape recognition directory
• [[mw3f src/image/shape_recognition/RECOGNIZE]] : recognise a shape from the shape recognition directory
• [[mw3f src/image/shaperecognition/SRDEMO]] : demonstration of the shape recognition module

miscellaneous

• [[mw3f src/curve/matching/KM_DEMO]] : demonstration of the curve matching algorithms
• [[mw3f src/image/detection/VP_DEMO]] : demonstration of the curve alignment module
• [[mw3f src/image/io/Mkmovie]] : build a movie from an image sequence
• [[mw3f src/signal/Swtvdenoise]] : suite of modules invocations for denoising
• [[mw3f src/wave/packets/Wp2dcheck]] : check and demo of the 2D wavelet packets module

1. Maria is an image processing researcher. She wants to use, try or compare recent algorithms and methods.
2. Hakim is an image processing researcher. He wants to show and distribute his new algorithms and methods.
3. Hiroko is developing some image processing software or hardware; she wants to include recent and efficient algorithms.
4. Marc is a math teacher. He needs to show how various image processing tools work, and he needs a framework to help his students try things with this kind of tools.

For all af them, megawave intends to provide a solution.