Collection of Tools & Utilities/Collection of Tools and Utilities.iso/graphic/trueview.zip/README

Text File | 1992-05-20 | 8KB | 135 lines

   Originally, I intended to supply no README file at all along with
TrueView.Exe.  Still, as the program messages proved not to be as
self-informative as intended, this brief readme emerged.  If you do not
have VGA with color monitor installed on your machine, I think it's wise
to stop now.  If you do have 'em - let's continue.

   This program was designed with the sole purpose in mind - to develop
tool, though clumsy and uncommon, which will permit to view two
different 256-colors VGA images on single screen _simultaneosly_ without
adjusting palette for any of them and (hopefully) to display true color
24-bit images.  Obviously, it's not a great task to everyone who have
Targa+ or SuperVGA with Tseng ET 4000 chip set, but to all us boys with
plain VGA it is a bit difficult.

   Obvious solution to this problem is to have three different images
displayed in three subsequent VGA frames, one for red component, next
for green and last for blue one.  Such technique could have resulted in
18-bits-per-pixel resolution (because of VGA palette been 6 bits wide
instead of 8 - such a pity!).  Unfortunately, such picture will flicker
too much, frying eyes in a matter of seconds.  Solution to this problem
came from Alex Young (Moscow, FIDO 2:5020/26), who suggested to include
a touch of each color to each frame, thus reducing overall flicker.
After that there were a lot of technical work with switching frames in
time and choosing the exact form of palette used on each of them, but
the initial impact was here already...

   Now, then you are sufficiently bored with these details, let's start
to work.  First, make sure to shut down each and every multitasker and
task switcher you'd started.  Because of delicate timing required to run
TrueView and non-standard ways of programming your hardware (i.e.,  VGA
and timer chips) it implements, the most probable outcome of running it
in multitasking environment will be the overwhelming need for Big Red
Switch.  TrueView will try to detect Windows 3.0, DesqView and DosShell,
so as to refuse to run from inside of them. Other multitaskers most
probably will go unnoticed, so beware.

   Prior to viewing any nice pictures you prepared for occasion, you
will have to tune TrueView for the display you are using.  You will have
to adjust vertical frequency used and three color response curves - one
for each of red, green and blue.  To do so, type:  'trueview -s' and
press <enter>.  Selecting vertical frequency is simple:  pressing '+'
and '-' keys, choose maximum frequency at which display is yet stable
and grid at upper and lower part of grid on screen do not look odd.  You
will be able to select any value from 65 (this should satisfy any VGA
monitor) to 100 Hz (this will work on some of the MultiSyncs only).
Note that the larger vertical frequency will mean less flicker later.
Then satisfied, press <enter>.

   You will see twelve calibration bars for red color response curve.
For each bar adjust intensity of strips in it by pressing Home (brighter
by 3), PgUp (brighter by 1), End (dimmer by 3), PgDn (dimmer by 1).  For
first bar (black one) select level which will become visible
_at_the_next_ press of PgUp.  Do not permit the textures of bars to
distract you - it is the intensity only that cares.  For myself, I
prefer to screw my eyes while adjusting these bars.  Then all bars seem
to be uniform to you, press <enter> and repeat process for green and
blue colors.  You will see tree color response curves for your monitor.
Just press <enter> to save configuration file.  By default, it will be
names gamma.m64 and should be placed at the same directory as
trueview.exe.

   I am sorry to make you to select 37 adjustable parameters before
you'd seen anything really pretty, but it seems to be the absolute
minimum necessary to make this technique work.  In my original version,
there were 190 parameters, so you are in a privileged position.  The cause
for such complexity is the complete neglect of color response curve by
most manufacturers - they prefer not to adjust zero beam current, so as
to save some money...on our's expense.  No one of monitors I'd ever seen
was even near at NTSC's standard gamma of 2,2.  And gamma = 1,6 assumed
by some Windows applications is no better.

   Well, now you are ready to view your favorite pictures in a new
light.  All you have to do is to type:  'trueview my_best.pcx
honey.tif'.  Both pictures will be displayed simultaneously.  You can
choose active one pressing <Tab> and <Shift-Tab>, scroll active picture
with cursor keys and display it full-screen with <Enter>.  Number of
pictures you can view simultaneously is limited only by number of files
program can open simultaneously.  On my system, I can view at least 15
files simultaneously.  You have to supply extension with file name, but
the extension is _not_ used to determine file type, so it needs not match
file contents.

   Now, few words on the graphic file formats supported. Formats capable
of supporting truecolor 24-bits images are marked by asterisk.

   BMP(*) files are supported according to full Windows 3.0 SDK
specification. Possible variations include 1, 4, 8 and 24 bits per
pixel. Run-length encoding mentioned (but not exactly clarified) in SDK
reference is _not_ supported. So is the Presentation Manager variation
of BMP, which has different file header format.

   PCX files understood by TrueView are restricted to single plane
(1,2,4 or 8 bits per pixel) and single bit (up to 8 planes) images. For
256-color images, both PCXkit and ZSoft-style palettes are supported.
PCXkit was reported to span compressed sequenced over row boundary
sometimes, which contradicts to original PCX specification. Such images
will not be accepted.

   GIF files support is limited to version 87A specification.  For
multiimage file, only first picture will be displayed.  Both global and
local color palette should work Ok (but I had no images with local
palette to test it!).  Due to the complicated nature of GIF's
compression, all GIF files are expanded to temporary storage then first
opened.  If you have sufficient amount of XMS memory, expanded picture
will be stored here.  If not, TrueView will attempt to create temporary
file in directory pointed by TEMP environment variable or, if TEMP was
not set, in current directory.

   Implementation of TIFF(*) reader is the weakest spot of TrueView.
Still, the barbaric richness of this format will drive omnipotent God
himself inarticulate, so I am not to be blamed here.  I had chosen
(somewhat arbitrary) to support 4- and 8-bits-per-pixel paletted images
and 24-bit single plane RGB images.  Only two compression modes are
supported by TrueView - mode 1 (no compression) and mode 32773
(PackBits).  My implementation of TIFF reader deviates from TIFF 5.0
specification in one respect:  it assumes color response curve to be
uniform if none was specified in input file, while standard forces the
use of gamma = 2,2.  Still, from my little experience, assuming gamma to
be 1 is much more likely to produce good-looking pictures.  And if
application had not cared about it's picture appearance enough to
include color response curve in it, why should I?  Both Intel and
Motorola byte order should be supported, but I have no Mac-style TIFF
images to verify it.

   Oh, and license stuff - I'd almost forgot it ;-) Permission is hereby
granted to use this program freely to any person who is willing to do
so, provided that it will not be modified in any way from it's original
form and it will not be used in commercial purposes.  So, let's enjoy
the life, guys - it is such a pleasure sometimes!

05/20/92 Serge Pachkovsky,
FIDO: 2:5000/19
Internet: [e-mail]