The World of Computer Software/World_Of_Computer_Software-02-385-Vol-1of3.iso/d/dmorf010.zip/DMORF.DOC

Text File | 1992-12-21 | 8KB | 186 lines

DMORF Rel Alpha 0.09 (12/09/92)
Copyright (c) 1992, by David K. Mason

This is just a brief intro to get you going with DMorf.  It's not
a real document or anything.  Note: this is still a fairly early
alpha version of this program... it's prone to crashing at
inconvenient times, so save your warping meshes in files on
a regular basis.  I haven't worked on this program in quite a
while except to fix one last bug that had been sitting there since
March, and I probably won't get back to it for another long while.
Feel free to report bugs, but don't expect 'em to get fixed too
soon.

To run DMorf, you MUST have:
 1) A VGA monitor (regular VGA is sufficient... DMorf works only
    in 640x480x16 mode)
 2) At least a '286
 3) A mouse with a microsoft-compatible driver

To accomplish any serious work with this program, you SHOULD have:

 1) A numeric coprocessor... it DRAGS without one

 2) Plenty of XMS or EMS unless you're working with teeny pictures.
    During the warping process, DMorf creates a buffer
    big enough to hold one entire picture, in RGBa (32-bit)
    form.  That means 256000 bytes if you're working with
    320x200 pictures, or 1,228,800 for 640x480, or 1,920,000
    for 800x600, or 3,145,728 for 1024x768.

To get started with DMorf, type "DMORF <file1> <file2>".
The files can be TGA (16, 24, or 32, compressed or uncompressed),
Vivid IMG, or GIF.  The two files don't have to be in the same
format, but they do have to have the same dimensions.
DMorf doesn't currently check to make sure they have the same
dimensions, so if you mix 'em up, you might get REAL odd results,
run-time error, or both.

The only type of output DMorf creates is compressed Targa-32
files.  VPIC and PICLAB have some trouble reading the output files,
because the run-length packets span lines.
DTA can read 'em okay, though.

DMorf will then read and display the two pictures in side-by-side
windows.  If you only gave one filename, then it'll display
that picture twice.
It scales 'em so they'll fit in the windows.

Then, a mesh is laid over the two pictures.
In this program, a mesh is represented by a bunch of horizontal
and vertical lines.  The points where they intersect can be
adjusted.
Initially, there are lines on the four edges of the picture,

There are always the same number of mesh points defined in the
two pictures, though they aren't always in the same places
unless the meshes are locked.

To add a new line to the mesh, move the mouse cursor to the
border around one of the pictures (which one doesn't particularly
matter).  Click the button at the point where you want the line
added.  (If the cursor is on the top or bottom border, a vertical
line will be added, and if it's on one of the sides, a horizontal
line will be added.)

To move a vertex, put the mouse cursor over the intersection
of two lines, press the button, and move the mouse.
Let go of the button when you've got the point where you want
it.  DMorf will try to prevent you from overlapping lines.
It's possible to defeat it with weird angles.  It's best if
you don't, however.

Here's what the other controls on the screen do:

 Just Warp:  In Morph mode, the program will map points from
   picture #1 toward picture #2, and from 2 toward 1, and
   cross-fade.  In Warp mode, it'll just map points from
   #1 toward #2, with no fade.
   Not too surprisingly, Warp mode takes half the time
   that Morph mode does.

 Spline meshes:
   When your points are all located where you want them to be,
   and you tell DMorf to go ahead and morph, DMorf figures out
   which points to map where by drawing spine curves between
   the vertices.
   If you turn this control off, it'll draw straight lines instead.
   Reasons to use slines instead of lines: the warp often looks
   a whole lot better.
   Reasons to use lines instead of splines:
   (1) Splines sometimes go haywire, with curves going every which
       way, overlapping, and (gasp) sometimes even passing beyond
       of the picture borders
   (2) You don't want something curved when it warps
   (3) lines are faster than splines.

 Smooth resampling:  In smooth mode, DMorf interpolates
   new pixel values from all source pixels that should
   contribute... if you turn this control off, it just
   grabs a the closest pixel value.
   Nearest neighbor, in other words.  The results
   in smooth mode look massively better than dumb mode.
   But dumb mode is massively faster.  Dumb mode would be
   useful in test runs, but don't use it for real stuff, 'cause
   it looks like crap.

 The Mesh colors "R" control: sets the red component of the color
   used to display the control mesh.

 The Mesh colors "G" control: sets the green component of the color
   used to display the control mesh.

 The Mesh colors "B" control: sets the blue component of the color
   used to display the control mesh.

 The Frames control: tells DMorf how many pictures to create.
   If you're in Morph mode, then this represents how many tween
   frames to create.  In warp mode, this number includes a
   fully-warped final frame.

 The Swap button: swaps the meshes between the two windows.

 The Copy 1->2 button: copies the mesh from window 1 into
   window 2.

 The Copy 2->1 button: copies the mesh from window 2 into
   window 1.

 The Splines button: gives you a preview of what splines for the
   current mesh points would look like.  If you're using
   "Spline meshes" mode, make sure you use this button once in a
   while to make sure the splines aren't going nuts.

 The Zoom buttons: display just one of the images, much larger.
   This gives much finer control over the mesh control points.

 The Save button: saves your meshes and settings to a control file.

 The Load button: loads a control file.  Type the filename right the
   first time or you'll get a run-time error and get dumped out to
   DOS.

 The Go button: causes DMorf to start morphing.

 The Abort button: Changed my mind.  Get me out of this program NOW.
   The escape key does the same thing.

If all this makes no sense, just start messing around with the
program.  Once you figure out how to add new points to the mesh,
the rest of the interface is pretty intuitive.

Credits:

The warping and morphing algorithms come from George
Wolberg's book Digital Image Warping.
The image scaling and spline code come virtually unchanged from the
same book (except for translating it from C to Pascal).
I ripped the line drawing routines off from PC Magazine's
book Turbo Pascal 6.0 Techniques and Utilities, by Neil Rubenking.
I don't remember what other places I stole stuff from.
Much is actually my original work, though.
Thanks to the Compuserve GRAPHDEV forum gang, and the Graphics
Alternative BBS gang for their suggestions, and various bugs
they've helped me identify.

Stuff I'm going to add or change (sooner or later):

1) Deletion of mesh lines.
2) A better way of adding mesh lines.
3) Proper handling of the alpha channel.  Right now DMorf takes
   the alpha byte from TGA-32s into account, but I haven't
   bothered to make it work with them right.
   Since I don't actually have any test files with real alpha
   info in them.
   I'm also going to have to write a little program to add alpha
   info to pictures (a seed fill to alpha out the background
   is a method suggested in Foley & Van Dam).
   And write a program to do compositing (or add that capability
   to DTA).
4) Or, forget that alpha stuff and add some kind of mechanism for
   cropping out the background.

-- David K. Mason
   P.O. Box 181015
   Boston, MA 02118