| Here's some more fuel for the fire; I found this on Steve (VirusX)
Tibbetts BBS. This same text is available on CRISTA""::AMIGA: as
DCTVVSHAME.LZH. While there's no "official" header stating so, the
disclaimers at the end and references made throughout indicate that
this doc was created by Black Belt Systems, but I can't vouch for
it's authenticity or accuracy, etc, etc. Anybody local to their
BBS care to give them a call at (406) 367-ABBS ?
Differences between the HAM-E and DCTV
--------------------------------------
Updated June 5th, 1991
Due to the massive pre-advertising campaign mounted by Digital
Creations for their DCTV product, many customers begin their questions
to us with, "How does the HAM-E compare to DCTV", or a very similar
phrase. They want to know why they should buy a HAM-E "instead". This
is a fair question - This short document presents some of our answers.
As you read this, keep in mind that the issues discussed here refer to
the current state of both systems as of the end of May, 1991. We cannot
know in advance what Digital Creations may do that might affect the
information presented here, and so as time moves on this information
may become less accurate. Similarly, Black Belt will continue to
improve both the HAM-E and it's support software.
Evaluation of the Digital Creations DCTV device has been done from a
production unit purchased by Black Belt Systems from an authorized
Amiga dealer (Leigh's computers, in New York... they also carry the
HAM-E unit, if you're in the region and want to compare the units).
General Information on DCTV marketing questions
===============================================
Black Belt Systems has completely decoded the DCTV image format. This
was done in order to allow us to verify the statements that Digital
Creations has been making in their advertising regarding the
capabilities of the DCTV unit.
Our conclusion is that Digital Creations advertising can be misleading
on the points presented below.
Direct quotation from Digital Creations ad:
"Display and capture full color 24 bit high resolution images"
Issues:
First, DCTV cannot capture or display images that have color
information which exists in approximately 75% of the 24 bit image
space. This limitation is due to the NTSC composite video
encoding standard. Digital Creations has stated publicly that
DCTV can only display "about 4 million colors". We believe this
to be optimistic at best, but even if you take it as the absolute
truth, what about the other 12 million colors in the 24 bit
space? Clearly, the marketing statement in the ad implies that
DCTV can deal with 24 bit images. The question boils down to:
What does "full color 24 bit image" mean?.
You should know as a (potential) DCTV user that it does not mean
you can capture or display images with 24 bits of brightness/color
information in them. (Beginning to see why we point the statement
out?) The DCTV software can save images in 24 bit IFF format; but
that has no bearing on what is actually contained in the image.
You can save a 2 color image in a 24 bit file... that doesn't
make the image itself 24 bits accurate.
Next, DCTV can indeed capture high resolution images in the
Amiga sense (640 horizontal resolution or thereabouts). However,
DCTV can only display in low resolution, in the Amiga sense (320
horizontal resolution or thereabouts), and that only if the image
is black and white (luma only).
If the image contains color (chroma) information, that color
information is displayed with less than 1/6th the spatial
resolution of Amiga "low" resolution (320x200). DCTV produces
pixels that are staggered one high-resolution pixel width from
each other on alternate lines, but the pixels themselves are
presented at the low resolution rates.
This characteristic of DCTV allows them to produce images with
diagonal information with better fidelity than a non-staggered
lo-res display (such as the HAM-E), but it also prevents them
from displaying a vertical line correctly, which a HAM-E can do
very well; all vertical lines in a DCTV display contain visible
jagged edges. To illustrate, DCTV produces low resolution pixels
in the following manner:
- - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - -
In the above pixel placement diagram for DCTV, each PAIR of scan
lines provides color information; each individual scan line
provides luma (brightness) information. We call this inability to
display a vertical line the "Zipper Effect".
In comparison, the HAM-E produces low resolution pixels in the
following manner:
- - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - -
In the above pixel placement diagram for the HAM-E, each pixel
can produce a 24 bit, 18-bit, or a combination of 18 and 24 bit
accurate color. Each scan line is completely independant of other
scan lines. Vertical lines are displayable with no "zipper".
Quotation from Digital Creations ad:
"DCTV creates a full color NTSC display with all the color and
resolution of television"
Issue:
Any properly operating, good quality television can display more
colors than DCTV can produce, by a huge margin (millions of
colors) simply because a "real" television signal can contain
many more luma (brightness) levels than DCTV can produce. Any
properly operating television can also display images with
approximately three to four times the spacial resolution of DCTV
from a digital composite OR an analog source (for instance,
zippers on vertical lines aren't mandatory in composite digital
video, nor must pairs of scan lines have colors that are the same
other than luma content - as witness NewTek's Video Toaster
output).
Specifically, a television can display different colors derived
from line-independant chroma signals on each scan line while DCTV
cannot, and the luma resolution (black and white detail) is much
higher than DCTV can produce for display purposes.
Clearly, the statement in the ad may mislead the reader if said
reader is not aware of the many issues that underlie the
generation of digital composite images from a 7mhz sample rate
data stream.
Output Comparison
=================
HAM-E: RGB output. On the standard Targa Eagle image, you can see
crisp, clear details in the red flower, and you can see every
letter of the copyright message clearly - it is perfectly
readable. The HAM-E's usable resolution is 384 colors and/or
luma changes per scan line in the basic unit. 482 lines in NTSC
mode, or 570 lines in PAL mode. These are exact technical
specifications measurable at the monitor screen, not marketing
hype. The HAM-E can produce colors anywhere in the 24 bit color
space, with no exceptions - that's 16 million possible colors.
DCTV: Composite output. On the standard Targa Eagle image most
of the red flower's petals are blurry or invisible; the colors
"bleed" off of the right edge of the flower and don't start soon
enough at the left edge of the flower. The copyright date is
indistinguishable on our production model DCTV. We *estimate*
DCTV's usable display resolution to be approximately 125 chroma
changes per PAIR of scan lines and about 300 luma (brightness)
changes per scan line. DCTV can produce 482 scan lines in NTSC,
but has no PAL mode. Fact: DCTV is neither 768 pixels per line
"sharp" nor 24 bit color accurate when measured at the monitor
screen.
For the record, Digital Creations representatives are currently
claiming output color capability of "about 4 million" colors.
DCTV image output specifications which Digital Creations has not
published, but which have been carefully verified at Black Belt
Systems, and presented to the Digital Creations representatives
on the "BIX" telecommunications network without any rebuttal:
Horizontal Luma Resolution: 320
Chroma Changes per line: 80:80 (80 for R-y, 80 for B-y)
Max color changes per line: 160 (not including luma changes)
Vertical Luma resolution: Same as number of lines in image
Vertical Chroma resolution: Half that of number of lines in image
Pixel offsets between lines: 70 ns. (1 hires pixel)
Display Mixing Comparison
=========================
HAM-E: Shows it's images on your RGB monitor, allowing the use of
mixed-mode slide shows (normal Amiga screens like hi-res and
HAM) mixed with HAM-E mode screens) in AmigaVision, etc. HAM-E
screens behave just as you'd expect by going up and down, front
to back, etc. HAM-E screens "fit in" to your system seamlessly
in this respect.
DCTV: Images require the use of a separate composite monitor or
separate composite input. DCTV images cannot be mixed with
standard Amiga images, so you can see either DCTV or Amiga
graphics, but not both. If Amiga-M is pressed, for instance,
your screen goes black. No mixed mode slideshows, and no use of
Amiga screens as control panels or other utilites, such as file
requesters.
Image Digitizization Comparison
===============================
HAM-E: Uses sharp RGB digitizer "DigiView" by NewTek directly, resulting
in excellent RGB images. No extra costs for building in a
feature many Amiga owners already have. Cost of the basic HAM-E
plus DigiView is still less than the DCTV retail price. DigiView
requires only an inexpensive B&W camera; can digitize from a
color camera or high-quality still VCR with inexpensive
"splitter" accessory. System consisting of HAM-E + splitter +
DigiView + B&W camera, all new, costs far less than DCTV + color
camera, also all new.
DCTV: Uses built-in composite digitizer. Blurry results as compared to
RGB digitizing. Duplication of equipment for anyone who already
owns DigiView. Images are not capable of as good a reproduction
quality as DigiView. Will digitize composite color images when
frames are frozen (possible only on top of the line VCR's and
color cameras).
Digiview note:
==============
Digiview internally codes images in 21 bits of RGB data. Images
you may have seen on a normal Amiga display do not allow you to
see all of this detailed information. For this reason, many
people have gotten the mistaken impression that Digiview cannot
produce images of comparable quality to DCTV. This is
incorrect. Digiview produces RGB accurate pixels at a spacial
resolution equal to the DCTV digitizers composite pixel
samples, and at twice the spacial resolution of the DCTV
display hardware. Digiview's color accuracy is much higher than
the DCTV digitizer, on the order of 3 to 4 times. For instance,
Digiview will digitize a blue line one pixel wide next to a red
line one pixel wide with no errors. DCTV will produce a purple
blur with the same input image.
Technical Development Support Comparison
========================================
HAM-E: Open technical support. Anyone can develop software to work with
the HAM-E. We provide source code, autodocs, technical
assistance, etc on our public BBS at (406) 367-ABBS. This
results in high-quality support from other manufacturers, and
means that our customers have more options. We not only provide
source code, but we provide libraries with unmatched
functionality; blitted bob support, color cycling, image save,
image encode, image decode, font support, color-font support,
scrolling, line draw, ellipse draw, and more.
DCTV: Closed technical support. The DCTV image format is held secret
by digital creations. This means that it is difficult or
impossible for third party-organizations to create support or
add-on software. This will adversely affect the Digital
Creations customer. There is a "DCTV Library", but currently it
only provides image encoding functions.
Hardware and Software Product Support from manufacturer Comparison
==================================================================
HAM-E: Current support from Black Belt includes:
* highly advanced 256 color paint system including ARexx, Macros,
ColorFonts, powerful animation, UnDo, User-definable key
remapping, loading of 35 "alien" image formats including DKB,
DBW, GIF, Targa, and almost any possible IFF image, direct save
of 24 bit, GIF and HAM-E mode images, "live" blitted brushes
made from arbitrary clipped regions, as well as all standard
paint features.
* 24 bit paint capability with 24 bit ranges with up to
256 control points; painting with 24 bit clips or solid brushes;
multi-dimensional transparency controls; 9 fill modes; undo;
redo; HSV, HSL, RGB and CMY palette controls; brushes that allow
std painting, "wetting" painting, "drying" painting, range
painting; and more.
* We provide the best image processing software available on the
Amiga, with well over 200 functions. Higher spatial resolution
hardware upgrades for the HAM-E itself are also available from
us.
* Write IFF 24, viewable HAM-E files, and GIF 256 color images. Read
GIF, Targa, standard IFF (2-32 color, 1/2 brite, HAM), IFF 24,
IFF 24 + CLUT, IFF 21, IFF 18, IFF 15, IFF 12, IFF 9, IFF 8, DKB
trace, DBW render, RGB8, RGBN, RGB raw, QRT Trace, ARZ0, ARZ1,
SHAM, Dynamic HiRes, AHAM, 8 bit IFF images. Many of these file
types have multiple variants; we have made a concerted effort to
support these additional format permutations.
* Software that allows use of DigiView 4.0 directly is part of
the 24 bit painting and image processing system.
* 2 Libraries that allows reading and writing of HAM-E images,
direct support for fonts, ColorFonts, blitted brushes, scrolling,
read color register, write color register, draw line, draw
(filled/unfilled) ellipse, draw (filled/unfilled) rectangle,
color cycling, and complete "BOB" (Blitter object) handling
facilities. Ability to render HAM-E images in multiple modes
from 24 bit source buffers.
* Over 400k of on-disk documentation describes every aspect of the
HAM-E system's operation, and a small printed manual describes
the hardware and it's installation. A printed manual that
describes the software will be supplied to all HAM-E owners who
have registered their HAM-E units with us some time this summer
(July-August release time frame is planned) at no charge.
DCTV: Current support from Digital Creations includes:
* Very nice composite paint software that has most standard paint
functions, but not all. DCTV paint does not include Undo, Color
Fonts, ARexx, Macros, Animation capability, ability to load
alien file formats, and will not "blit" brushes - you are forced
to move an outline of a "clipped" region, let go, and then
"tack" it down. You can't draw with clipped areas, and so they
are not "brushes" in the usual Amiga sense.
* A minimal set of image processing tools, 9 functions which are
simple global brightness, color, and tint type controls.
* Write 24 bit IFF, "raw" files, or viewable DCTV images. Read IFF,
DCTV raw files, and viewable DCTV images.
* Digitizer control software is also included.
* 1 Library that allows developers to write DCTV images from a 24
bit source, no other capabilities.
* Extremely well-written manual describes the operation of
the entire DCTV system.
Comparison Of Additional Support From Other Vendors
===================================================
HAM-E: Commercial paint software, the "HAM-E WorkShop" from Holosoft
Technologies. ASDG's "The Art Department Professional", AKA
"TADPro"; PD DKB Render; Progressive Peripherals "3-d
Professional" ray tracer; PD "HAMLab"; Several PD viewers which
not only support the display of HAM-E images but also support
color cycling them.
Other software, including 256 color games, is currently under
development with other vendors. Oxxi's "Spectracolor" is in the
process of being incarnated in a full HAM-E version - early
images from this splendid paint program are stunning! Oxxi indicates
that a release date of July 15th, 1991 is planned. PD tools
such as DBW Render and "Vapor Paint" are working on direct
support as well.
DCTV: Support in 3-d professional.
No other support software from other vendors. None is known to be
pending, and none is likely to appear without special co-
operation from Digital Creations, except for render output using
the "DCTV library".
Genlocking
==========
The HAM-E hardware has full support for genlocking. Current production
units work very well with Digital Creations own "Supergen" genlock
(the external model only, of course). Genlock operation of the HAM-E
does require the purchase of a specially constructed low-noise video
cable. The cost of this cable is $30.00 US, and is available from
either Black Belt Systems or directly from Redmond cable.
DCTV cannot genlock at present. Digital Creations has announced plans
to release an extra cost adaptor which will allow genlocking, but price
and availability are both unknown at this time.
Video connector Pass-thru
=========================
Current Production models of the HAM-E pass thru all 23 pins of the
Amiga's output video jack. Other video devices should work 100% with
the output from the HAM-E's passthru. For instance, DCTV works when
attached to the output of the HAM-E.
DCTV does not pass thru the IRGB lines (actually, they place other
signals that are unique to DCTV on these pins which are intended for
the genlock adaptor). This means that other video devices may not work
when plugged into DCTV's passthru. For instance, the HAM-E cannot
operate correctly when plugged into the output off DCTV.
Display Mode(s) Comparison
==========================
HAM-E: Both "real-color" and 256 out of 16 million color modes. Full 256
grey scale capability. Direct image access via paint, BASIC "fd"
files, ARexx, C, assembly language, etc. Final image on screen
in real color mode is a mixed 18/24 bit image that generally
achieves full 24-bit accuracy to the eye. Final image on screen
in 256 color mode is completely 24 bit accurate. In real color
modes, the HAM-E can present a different color for every pixel
in an image.
DCTV: Only "real-color" mode. Limited grey scale (160 grey levels),
and your only direct access to DCTV's images is via their paint
software. No read capability in a library, no "fd" files, no
source code, no hints, no nothing. Final image on screen is a
composite image that achieves somewhere in the region of 20 to
21 bit accuracy to the eye, and a spacial resolution far below
Amiga "lo-res". DCTV can present a different color for every
pixel in an image.
Global System Compatibility Comparison
======================================
HAM-E: Works on NTSC and PAL (European) machines. This means that the
HAM-E can "get into" the European market - where most Amigas are
located. This means a larger number of HAM-E systems are likely
to be sold, and that, combined with our open technical support,
means that you as a user will benefit directly.
DCTV: Does not work on PAL machines. The market for DCTV is the (much
smaller) installed base of NTSC machines.
Price, Warranty, Upgrade Comparisons
====================================
HAM-E: $299.95 retail for the unit discussed here. $429.95 retail for a
specially-equipped unit with the same features, and additional
custom real-time image processing hardware which produces a
high resolution rate pixel output by synthesizing new pixels in
between the original low resolution pixels. Warranty is 3 full
years from the original purchase date, both parts and labor,
fully transferable. Our original warranty was not this long, but
when the change was made it applied retroactively to all HAM-E
units sold. The HAM-E unit is not sealed - you can look inside
and "adjust" things. We can provide a technical adjustment guide
for those who are inclined to hack and meddle. We also have a
"hacker's hints" guide on our BBS for those who are interested
in fine-tuning the hardware. When these changes are done
according to the guide, the warranty on the unit remains valid.
Software upgrades are free via our BBS, CIS, and Plink, or for a
nominal charge on disk via UPS.
DCTV: $499.95 retail. 90 day warranty, parts and labor. The DCTV box
is sealed, and the units warranty is void if you open it. This
information is taken from the provided DCTV manual.
Our Conclusions:
================
We truly believe that Black Belt Systems is offering a superior display
product in the sense that it can provide a better image, which is well
integrated into the Amiga's hardware and software.
We also believe that we provide superior support for the customer, and
we think this is borne out by the amount of new software, upgrades, and
general aftermarket activity that has appeared surrounding the HAM-E
since it's release in 1990.
If you have any doubts at all, we suggest that you locate a dealer that
has both units in stock and get a demonstration of both items. If the
dealer is unfamiliar with either DCTV's software or the HAM-E software,
you cannot expect a proper demo; in that case, look at the quality of
the images.
Trademarks and other Legal Esoterica
====================================
HAM-E is a trademark of Black Belt Systems. DCTV is a trademark of
Digital Creations Inc. TADPro and The Art Department Professional are
trademarks of ASDG Inc. Amiga and AmigaVision are trademarks of
Commodore Business Machines Inc. DigiView is a trademark of NewTek Inc.
Video Toaster is a trademark of NewTek Inc. HAM-E Workshop is a
trademark of Holosoft Techologies. "Eagle" image copyright TrueVision
Inc. ARexx is a trademark of William Hawes and Wishful Thinking.
SpectraColor is a trademark of Oxxi, Inc. GIF is a trademark of
Compuserve Information Services. 3-d Professional is a trademark of
Progressive Peripherals.
Errata
======
Black Belt Systems has made every effort to make the information in
this document accurate. If you discover inaccuracies, please contact
Black Belt Systems so that we can correct the problem ASAP. We have no
interest in providing deceptive information - we'll leave that to our
competitors, who seem to be quite good at it.
Disclaimer
==========
Black Belt Systems is not associated with ASDG or Holosoft Technologies
in any financial or legal manner. We co-operate with these companies as
we feel this best serves the interests of the HAM-E customer.
|