Hey, 

this is not a pov question, but you guys here (D.F. C.H. P.P. et al. )
are very reliable in your graphics knowledge so I figured I would ask
:-)

I am scanning in a lot of newspaper articles and need to find a good
format to store them in for others to view off of a CD-Rom. Currently
the uncompressed images are about 6Mb each (at 200 dpi scanning) which
is way too large. Any thogthts about the advantages or disadvantages of
JPEG or TIFF or PNG?

thanks a lot  again, sorry this is a non-pov msg in a pov group :-)

-paul
-- 



--------------------------------------------------}
Paul Daniel Jones
The Pennslyvania State University

pdj### [at] psuedu
http://research.chem.psu.edu/glassgrp/paul

       C            The way is near, but men
     // \           seek it afar. It is in the
    N    N          easy things, but men seek it
    |    ||         in the difficult things.
    C    C          -Menicius
     \\  /
       C
--------------------------------------------------}

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The best place to ask is at povray.off-topic.
Since I'm replying here anyway I might as well suggest just using
a high quality Jpeg for those.  Least compression.  Newspaper is
going to be pretty garbled by anything other than the least compression
setting you can use and yet be the smallest file size I think.
GIF would be good but then it's a licensed format so not sure how good
an idea that is.
PNG would simply be a large file size for such large images, imo.

Bob

"Paul Jones" <pdj### [at] psuedu> wrote in message news:391FE735.270BC29E@psu.edu...
| Hey,
|
| this is not a pov question, but you guys here (D.F. C.H. P.P. et al. )
| are very reliable in your graphics knowledge so I figured I would ask
| :-)
|
| I am scanning in a lot of newspaper articles and need to find a good
| format to store them in for others to view off of a CD-Rom. Currently
| the uncompressed images are about 6Mb each (at 200 dpi scanning) which
| is way too large. Any thogthts about the advantages or disadvantages of
| JPEG or TIFF or PNG?
|
| thanks a lot  again, sorry this is a non-pov msg in a pov group :-)
|
| -paul
| --
|
|
|
| --------------------------------------------------}
| Paul Daniel Jones
| The Pennslyvania State University
|
| pdj### [at] psuedu
| http://research.chem.psu.edu/glassgrp/paul
|
|        C            The way is near, but men
|      // \           seek it afar. It is in the
|     N    N          easy things, but men seek it
|     |    ||         in the difficult things.
|     C    C          -Menicius
|      \\  /
|        C
| --------------------------------------------------}

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Paul Jones wrote:

> Hey,
>
> this is not a pov question, but you guys here (D.F. C.H. P.P. et al. )
> are very reliable in your graphics knowledge so I figured I would ask
> :-)
>
> I am scanning in a lot of newspaper articles and need to find a good
> format to store them in for others to view off of a CD-Rom. Currently
> the uncompressed images are about 6Mb each (at 200 dpi scanning) which
> is way too large. Any thogthts about the advantages or disadvantages of
> JPEG or TIFF or PNG?

I would say that this depends very much on what viewing tools you expect
the end user to have.

And if you plan to enclose any viewing tools on the CD you will also have
to make assumptions of what platform (operating system) the end users have.

If you select a graphic web browser as the viewing tool:

JPEG: Good support (Good compression, but lossy)
PNG: Partly supported (Moderate compression, loss less)
TIFF: Poor support (Moderate/Poor compression, losses)
GIF: Good support (Moderate/Poor compression, only 256 colours)

JPEG would be a poor choice for images containing text and line art.
(I'm not sure how it performs with raster images as in the papers.)

I would also look at the possibility to enclose the Adobe Acrobat Reader
on the CD and select the PDF format for the image files. As far as I
remember Adobe Acrobat it is ported to several different platforms.

Postscript (PS) could also be an alternative.

If I had to choose (without knowing more about the end users),
I would have selected the GIF format (In combination with HTML
pages with thumbnails.)


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

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Tor Olav Kristensen wrote:

> TIFF: Poor support (Moderate/Poor compression, losses)

Sorry: loss less


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

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In article <391FE735.270BC29E@psu.edu>, Paul Jones <pdj### [at] psuedu> 
wrote:

> I am scanning in a lot of newspaper articles and need to find a good
> format to store them in for others to view off of a CD-Rom. Currently
> the uncompressed images are about 6Mb each (at 200 dpi scanning) which
> is way too large. Any thogthts about the advantages or disadvantages of
> JPEG or TIFF or PNG?

JPEG: Small file size, lossy compression, 24 bit color. I think there is 
a new JPEG standard(JPEG 2000?) that features lossless compression, but 
I don't know any programs that use it.
TIFF: No idea, never used it. It doesn't seem very common.
PNG: Lossless compression. File sizes can be a bit large compared to 
JPEG, but small details and colors are preserved. Best if you want 
top-quality images. Not sure about possible bit depths, but I think 
there are 16, 32, and 48 bit versions.

JPEG and PNG are supported by most web browsers, but I don't know about 
TIFF.

> thanks a lot  again, sorry this is a non-pov msg in a pov group :-)

Maybe povray.off-topic would have been a better group...

-- 
Christopher James Huff - Personal e-mail: chr### [at] yahoocom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://chrishuff.dhs.org/
TAG Web page: http://tag.povray.org/

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Paul Jones wrote:

>Currently
>the uncompressed images are about 6Mb each (at 200 dpi scanning) which
>is way too large.

If the content is black and white and the screen is coarse enough, reduce 
the amount of colour to two and then use PNG or GIF.
Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/

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Paul Jones wrote:
 
[snip]
> is way too large. Any thogthts about the advantages or disadvantages of
> JPEG or TIFF or PNG?
> 

PNG is probably best for newspaper scans. It is a verbatim (lossless) format and
compression is almost as good as JPEG (sometimes even better than a 100% quality
JPEG). The problem is that PNG is not as widely supported as JPEG, and many
viewers do not support it fully (e.g. they ignore the gamma information stored
in the PNG file, and may be confused if an alpha channel is present).

JPEG is a surefire format in that it is very widely supported. However, it is a
lossy format. It was developed primarily for storing photos, and is not well
suited for high-contrast images, such as b/w text. Verey high quality JPEG shoud
work OK, but you lose the compression advantage over PNG.

TIFF is a very flexible format, but its main advantages are in image processing
and printing, not bimap storage. It supports some compression, but file sizes
will remain large.

-- 
Margus Ramst

Personal e-mail: mar### [at] peakeduee
TAG (Team Assistance Group) e-mail: mar### [at] tagpovrayorg

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On Mon, 15 May 2000 08:01:57 -0400, Paul Jones <pdj### [at] psuedu> wrote:

>Hey, 
>
>this is not a pov question, but you guys here (D.F. C.H. P.P. et al. )
>are very reliable in your graphics knowledge so I figured I would ask
>:-)
>
>I am scanning in a lot of newspaper articles and need to find a good
>format to store them in for others to view off of a CD-Rom. Currently
>the uncompressed images are about 6Mb each (at 200 dpi scanning) which
>is way too large. Any thogthts about the advantages or disadvantages of
>JPEG or TIFF or PNG?

If you can convert to black and white (duotone, not grayscale) then
GIF, PNG, TIFF and BMP/RLE should offer about the same compression. Of
these, GIF enjoys the largest user base and can be viewed with
virtually any browser or image displaying program.

If you really need color, then go for JPEG. A CD can hold about
twenty-five to fifty thousand square inches of 200 dpi color JPEG data
without noticeable degradation of image quality. Even highly lossy
JPEG compression doesn't hurt high-resolution images very much because
JPEG is based on 8x8 pixel blocks and it's lossiness in mostly an
issue when these blocks are easily visible.

TIFF is the most flexible format of all but you'll probably only need
to work with it if you plan to print these in a print house.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG      e-mail : pet### [at] tagpovrayorg

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