Re: imread/imwrite

[John W. Eaton]

On 14-Dec-2007, Søren Hauberg wrote:

| I think it would be nice to have imread/imwrite in Octave. These
| functions do however add a dependency on ImageMagick.

Aren't those just run-time dependencies?  If ImageMagick is not
installed, don't the imread/imwrite functions throw errors?

I think more important new dependencies are libpng and jpeglib.  I
also just noticed this statement in jpgread.cc:

 // This is a hack into octave 
 //   based on jpgread.c by jpgread by Drea Thomas, The Mathworks and the
 //        examples in the IJG distribution. 
 //

Where did jpgread.c come from, and what is its license/distribution
status?

| If you add these functions, what should happen with
| loadimage/saveimage? And what about the Octave image format? Should
| it be removed or should imread/imwrite be changed to support this format?

I think we can keep the functions for now.  Eventually I think we
should at least move those functions to the deprecated directory and
maybe eventually remove them since doing that doesn't make it much
harder to read old Octave-format image files (they are simply two
matrices stored in an Octave data format, so it is easy to read them
with load).

| P.S. If the imshow function is called with a file name instead of an
| image it loads the image of disc and displays it. For this, it currently
| uses loadimage, but if imread gets added I think that function should be
| used instead.

Yes, that would be a good change to make.

OK, this is a little more complex than I thought (thanks for pointing
out some of the finer points) and so it can probably wait until after
3.0.  But I would definitely like to make these changes for 3.1.

Thanks,

jwe