image formats

[Thomas L. Scofield]

Currently there is this list

    bmp, gif, jpg, jpeg, pbm, pgm, png, ppm, svg, tiff

of file extensions hard-coded into a cell array in imwrite.  These comprise a "starter list" of supported image formats and, to some extent, acceptable file extensions for the file you write to.  Any list we come up with will be somewhat artificial, as the GraphicsMagick library allows writing to many more formats than we are ever likely to support.  (For a full list see http://www.graphicsmagick.org/www/formats.html).

First, I think this list should be augmented.  I would immediately add tif (not new, but an oft-used extension), ras, perhaps psd, eps, and jp2.  What do others think about this list?  How about additional formats others think important to support?  Ones not yet mentioned but that Matlab supports include hdf (it does not appear GraphicsMagick includes that one on its list of supported formats), ico, pcx, pnm and xwd.

Matlab, as part of its core, I believe, has the function imformats whose output looks like

>> imformats

 

EXT       ISA     INFO        READ      WRITE     ALPHA  DESCRIPTION                            

------------------------------------------------------------------------------------------------

bmp       isbmp   imbmpinfo   readbmp   writebmp  0      Windows Bitmap (BMP)

cur       iscur   imcurinfo   readcur             1      Windows Cursor resources (CUR)

fts fits  isfits  imfitsinfo  readfits            0      Flexible Image Transport System (FITS)

gif       isgif   imgifinfo   readgif   writegif  0      Graphics Interchange Format (GIF)

hdf       ishdf   imhdfinfo   readhdf   writehdf  0      Hierarchical Data Format (HDF)

ico       isico   imicoinfo   readico             1      Windows Icon resources (ICO)

jpg jpeg  isjpg   imjpginfo   readjpg   writejpg  0      Joint Photographic Experts Group (JPEG)

pbm       ispbm   impnminfo   readpnm   writepnm  0      Portable Bitmap (PBM)

pcx       ispcx   impcxinfo   readpcx   writepcx  0      Windows Paintbrush (PCX)

pgm       ispgm   impnminfo   readpnm   writepnm  0      Portable Graymap (PGM)

png       ispng   impnginfo   readpng   writepng  1      Portable Network Graphics (PNG)

pnm       ispnm   impnminfo   readpnm   writepnm  0      Portable Any Map (PNM)

ppm       isppm   impnminfo   readpnm   writepnm  0      Portable Pixmap (PPM)

ras       isras   imrasinfo   readras   writeras  1      Sun Raster (RAS)

tif tiff  istif   imtifinfo   readtif   writetif  0      Tagged Image File Format (TIFF)

xwd       isxwd   imxwdinfo   readxwd   writexwd  0      X Window Dump (XWD)

It seems like it would be easy to expand the above-mentioned cell array to include all of this kind of information, and move it out of imwrite to some more publically-viewable area so we can have an imformats command.  I don't know where that should be.  Suggestions?

Thomas L. Scofield

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Associate Professor

Department of Mathematics and Statistics

Calvin College

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