#Data conversion
5 messages in this thread
I am working on a project that will involve putting 4k-50k images onto a
CD-ROM. We plan to write the access software ourselves, but would like to
get help on the data conversion. We have manual pages with parts diagrams
on them. So far we've been thinking about using a pcx format, but we are
concerned about size and would like to consider vectorizing the images.
Does anyone have advice on the relative merits of these (or other)
approaches? Reccomendations about data capture companies would also be
helpful.
thanks,
dy
There are 3 Replies.
David, We (Reference Technology) typically use CCITT Group IV compression
for parts-manual type applications with line drawings. Compression is much
better than PCX: usually averages around 20:1 or better. If you have any
significant amount of half-tone material, however, things get worse in a
hurry! Group IV is a lot more difficult than PCX to decompress: you'd
probably be better off buying that technology (from us, for instance ….)
than re-inventing it. Tony Lavender
David, as Tony pointed out group IV is better compression. It really
depends on how many images you want to cram on a CD. We do image capture
here at Nimbus for several customers. If you ever got a chance to look at
one of our ROMware demo discs, you'd see extended VGA images we've captured
with our Jovian Logic/JVC system. Does a real decent job, but again, the
size of the image is substantial. Janes Info Group (military images) uses
us. We'll be glad to answer any other concerns you may have.
1-800-782-0778.
There is 1 Reply.
Ernie, just browsing by the forum when I noticed NIMBUS … I've been
perusing ROMWARE and other packages with the interest to publish a CD-ROM
application. I understand that data files are stored in different formats
etc which then dictates retrieval/access methods.
What is involved in putting together a CD-ROM application ? From data
preparation to production ? Does the data exist as standard DOS files with
multiple indices defined into the data ? How is data retrieval/access
achieved ? Are there toolkits/commercial products available to aid the
process ?
Correct me if I am wrong, ROMWARE is such a tool and provides a development
environment as well as retrieval software for the CD-ROM publication. I did
not see any reference to a retrieval engine toolkit, i.e. ROMWARE users
must use the retrieval software provided by ROMWARE. That would seem
rather limiting from a software development point of view, what if a
different screen/display/interpretation of the data is required, would it
hook into external display drivers/routines ?
Regards, Caesar.
David,
We just happen to be a scanning house<g>. I'd second Tony Lavender's
recomendation of Group IV TIFF. For us they come in at least 3 times
smaller than PCX (frequently better, depends how 'busy' the image is). Also
consider what resolution you need things scanned at–changing from 300 to
150 dpi will probably halve the file size after compression, and _probably_
will still be acceptable for display and printing. (Stick with 300 if the
captions are in small type)
There is vectorizing software out there, but all that I've heard of
still needs manual assistance, which could cost more than mastering a
second disk. I'd really recommend getting a better handle on how many
images you've got, and how big they are: that order of magnitude
uncertainty makes it hard to estimate.
Also, are you thinking in terms of imaging text pages? If there're
any significant number of text pages involved, you can get another factor
of 20-50 compression on them by storing them as text. (We do OCR too).
We'll be glad to talk over the project with you, and maybe do a
(small, free) sample to give you an idea of the options. Call us
@(603)446-7307, or CMAIL an address and we'll send a brochure.
Frank Richards