Re: image formats

[Thomas L. Scofield]

I can think of two reasons, though I'm not going to try to argue that either one is very strong.  The first is you need some sort of internal list to appeal to if there is to be an imformats command.  The second is that some formats have "options" one would want to employ---for instance, setting the quality for a jpeg image.  Matlab's documentation spells out the various options it supports for the formats it offers, and to mimick them all (if that's a goal) will be tedious---I'm not necessarily intending to do so.  Later users who come along and find they can write to some more exotic format X will perhaps wonder why they have to accept default options (i.e., not allowed to specify their own).  But, to be fair, my guess is that the number of requests/complaints arising this way will be few.  And, there is always the "you want it, you write it" response.

On Aug 8, 2008, at 3:04 AM, Bill Denney wrote:

Thomas L. Scofield wrote:

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).

Is there a reason that we should not support all the formats that Graphics Magick does?  It seems like the best way to support all images would be to just let imread/imwrite try to read/write the image and if we get an error from Graphics Magick that the format is unsupported we pass that back to the user.  I don't see any reason to artificially limit ourselves to some arbitrary subset of image formats.

Have a good day,

Bill

Thomas L. Scofield

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

Associate Professor

Department of Mathematics and Statistics

Calvin College

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