leei@lightning.McRCIM.McGill.EDU (Lee Iverson) (05/07/91)
The vimage utility has been uploaded to export.lcs.mit.edu in the
files:
/contrib/vimage.README
/contrib/vimage.patch1.Z
/contrib/vimage-0.7.tar.Z
This distribution is mostly for bug fixes and a substantial increase
in the functionality of the FileDialog widget. It has also added the
beginnings of a menu interface.
-- vimage.README
vimage 0.7 May 6, 1991 -- Lee Iverson
This package is the first pass at a general image visualization tool.
It is a collection of Xt widgets which create a cohesive image viewing tool.
Why another one? The answers are of two types.
1) I wanted a widget that could be easily used either standalone or
embedded in a larger application. An earlier poll of
comp.windows.x searching for such a beast turned up nil.
2) I needed something that would alow arbitrary user-defined
extensibility to new image types and display variations. This
meant the adoption of an objected-oriented image type heirarchy (a
la Xt). Eventually such things as EdgeMap and ImageFlow can be
implemented and seamlessly integrated into the overall application.
Required tools:
- An ANSI C compiler. To this point (for my own convenience more than
anything else) I've written this thing in ANSI C (it's easier to
debug). If you don't have an ANSI compiler (GCC is available in
aeneas.mit.edu:/pub/gnu/gcc-1.39.tar.Z), then you are (for the
moment) out of luck.
Recommended tools:
- libXukc: This is a widget set which extends the functionality of the
Athena widgets considerably. They are available as part of the Dirt
interface builder system (export.lcs.mit.edu:dirt.A1.10.tar.Z).
Currently, the three components of this system I depend on are
included with this package.
- ad2c. This is an extremely useful way of providing a consistent
set of fallback application defaults. It essentially compiles the .ad
file for an application into a set of strings which should be loaded
into the application context at startup. Actually, ad2c is only required
if you change VImage.ad and want the new defaults compiled in as
fallback resources.
- ezMenu. This is a nice, simple Menu interface which gives a clean
and simple interface to the Athena SimpleMenu structure. I've
modified it slightly, but only to make it a little more robust.
Features:
- ImageViewport widget. A general viewport widget that deals well
with arbitrary resizing of the child widget. It is clearly derived
from the Xaw Viewport widget, and includes both it's copyright and
my own. There are actions and accelerators for moving the image
around inside the viewport.
- Image widget. A general purpose image viewing, zooming, and
examining base. This is the part of the system which is the most
volatile at the moment, since I have plans to extend this to an
ImageStack widget (i.e. a number of images overlayed on on
another!). A set of interaction primitives enable arbitrary image
zooming.
- FileDialog widget. A Mac-like modal File dialog widget. Needs some
work, but is quite functional and has a nice interface for only
selectively seeing certain files. Depends on the regexp(3) library
functions (included).
- CMManage. A set of routines for managing a consistent colormap
within an application in which there are a potentially broad variety
of different areas of the program which are trying to allocate
colors. This overrides the standard Xt StringToColor translations,
so that resource manager color definitions will work properly even
when this color manager is being used.
- An Xt-like class heirarchy of Image types. The analog for Core is
the GenericImage type. Two standard Image types are currently
provided: BitImage and ByteImage, both rectangular bitmaps.
ByteImage has a colormap associated with it. The image reading
functions (currently supporting only PBM, PGM and GIF) create one of
these types. The Image widget interfaces to a set of generic
object-oriented calls which are redefined (as necessary for the image
types).
Caveats:
- There is currently NO DOCUMENTATION (except this file). A little
bit of application default browsing and source code reading should
elucidiate things for now, but real docs will come along soon.
- I've only really tested this on a Sun4 OS 4.1 with mono and 8bit
color displays and on VAX/Ultrix, but my ability to get close
to other hardware is limited, so no guarantees that this will run on
other visual types than StaticGrey and 8 bit PseudoColor. Sigh!
- I still see occasional extremely large pixmaps being created.
Haven't manage to track it down yet, so be careful and watch server
memory. You'll know when it goes through the roof!
- If you are running the MIT sample server (patchlevel 15+), there is
a bug in XtDestroyWidget that bites pretty big. The R5 work has
forced an end to official patches for R4, so you will need to apply
the following patch in lib/Xt.
*** Destroy.c.~1~ Mon May 6 12:25:26 1991
--- Destroy.c Mon May 6 12:26:45 1991
***************
*** 225,233 ****
while (i < app->destroy_count) {
if (dr->dispatch_level >= dispatch_level) {
Widget w = dr->widget;
! if (--app->destroy_count)
bcopy( (char*)(dr+1), (char*)dr,
! app->destroy_count*sizeof(DestroyRec)
);
XtPhase2Destroy(w);
}
--- 225,234 ----
while (i < app->destroy_count) {
if (dr->dispatch_level >= dispatch_level) {
Widget w = dr->widget;
! /* This was writing well past the end of the list! -- leei */
! if (--app->destroy_count > i)
bcopy( (char*)(dr+1), (char*)dr,
! (app->destroy_count - i)*sizeof(DestroyRec)
);
XtPhase2Destroy(w);
}
Planned Extensions:
- Documentation. Some. Any...
- As mentioned above, conversion of the Image widget to an ImageStack.
- Better color management including gamma correction, color dithering,
better image dezooming (mag < 1).
- More image formats including full color images.
- A dynamic loading interface for image formats and associated support
functions. One of the really essential things for supporting an
experimental image-processing environment is the ability to define
special image types (e.g. EdgeMap or OpticalFlow) and allow the user
to use them in as transparent a manner as possible.
- Adoption of a generic image format that supports cross-platform
portable images with arbitrary data formats (also using dynamic
loading). I'm not sure whether something out there already will work
(maybe CGM), but if nothing really fits what I need, then (sigh!)
another image format.
- A shared memory image manager (probably a separate program) for fast
and efficient communication between image processing programs and
the viewer.
------------------------------------------------------------------------------
Lee Iverson McGill Research Centre for Intelligent Machines
leei@mcrcim.mcgill.edu Computer Vision and Robotics Lab
McGill University, Montreal
--
Lee Iverson McGill Research Centre for Intelligent Machines
leei@mcrcim.mcgill.edu Computer Vision and Robotics Lab
McGill University, Montreal