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Number: 2834
From: "negusm" <negusm@y...>
Date: Sat May 31, 2003  2:56 pm
Subject: Re: [ASC McLaren ] Photo section dilema

Body:
Well, I hate to have to say this but this is the skinny on JPGs vs
Bitmaps vs Gifs.

Gifs ARE compressed. It is a LOSSLESS compression. JPG is a LOSSY
compression. A JPG image is almost always smaller than GIF for
PHOTO like images because of the processing envolved which takes
into account the way the human eye works and how colors will vary
within a photo. Some of the image in a JPG is slightly altered to
allow for a maximum benefit of the compression. So what your
digital camera "sees" is not really preserved pixel for pixel in the
file.

HOWEVER, for pictures with a very small number of colors and
especially large AREAS of single colors (like a cartoon or a banner
with sinple text and no image effects), GIF is going to be much
smaller than a JPG. Gif only does 256 colors.

HOWEVER, you can bump up the compression on a JPG to make it smaller
than a GIF but your image will suffer "artifacts" embedded in areas.

If you are seeing JPGs bigger than GIFs it is probably that your
compression is very LOW when saving the JPG and at LOW compression,
a JPG starts to turn into a large file since it is doing almost no
compression. Also when you convert a JPG to a GIF you go from 16.7
MILLION colors to a mere 256 colors. You are throwing away ALOT of
your image.

A BITMAP is an exact pixel for pixel representation of an image and
is rarely compressed. There is RLE encoding of bitmaps but it isn't
much of a compression scheme.

-Mike



--- In ascmclaren@yahoogroups.com, tasmaniac1 <no_reply@y...> wrote:
> Marq,
>
> Do you mean .Bmp's to .jpg? .GIF's are even smaller then .jpg's.
>
> -Nick
>
>
>

--- In ascmclaren@yahoogroups.com, "InfoSysSec" <infosyssec@i...>
> wrote:
> > Errrmmm... ah... unfortunately I have the knowledge of the
various
> fun things about the Net and so I will toss in a few pearls of
> wisdom on this topic.
> >
> > With respect to the beautiful pictures of the cars. The ground
> rules about posting or submitting pictures should be :
> >
> > a) all pictures submitted should be in a 640 X 400 pixel size.
> Any larger size gobbles up bytes like you would not believe. You
> can usually average five to ten 640 X 400 pixel pictures for every
> one 1280 X 1000 picture. Or to put it in simple terms a 10k
> picture compared to a 160k picture.
> >
> > b) all pictures should be submitted in the .jpg format. Many
> pictures are submitted in the .gif format which is wasteful.
> The .jpg format was created to provide the same quality of picture
> as a .gif formatted picture - however through the magic of
> compression a .jpg picture is ALWAYS smaller than the same picture
> in a .gif format.
> >
> > There are 'free ware' software programs available that can '
> resize ' pictures to the 640 X 400 format ( which is roughly the
> physical size of a standard camera taken photo print. The
larger
> pixel size pictures usually have the physical size of a 8 1/2 X 11
> inch picture.
> >
> > There are also 'free ware' software programs that can take
convert
> a .gif picture to a .jpg format.
> >
> > In some cases there are 'photo' programs available that can
permit
> the resizing of photos and also provide the option to save the
photo
> in the .jpg format ( even when you have loaded the picture into
the
> program from a .gif format ).
> >
> > Then to take things even further.... there are programs out
> there called JPG Crunchers. Basically what they do is take
a .jpg
> file and further compress it to a smaller size while still
> maintaining the quality and appearance of the picture. I have
> taken 16k .jpg files, run them through a JPG Cruncher and the
result
> was a 5k compressed .jpg ( using a 30% reduction ).
> >
> > In all of the above cases, the photos will maintain their good
> looks, be greatly reduced in physical size, and be downloadable at
> an obviously greater speed than the big lumpy fat bloated pictures.
> >
> > So hopefully this information will answer the key questions of
how
> to more efficiently save and store pictures submitted for display.
> >
> > Marq
> >
> > ----- Original Message -----
> > From: cassman108
> > To: ascmclaren@yahoogroups.com
> > Sent: Saturday, May 31, 2003 9:41 AM
> > Subject: [ASC McLaren ] Photo section dilema
> >
> >
> > I would also be willing to put a few bucks in to keep the
photo
> > section going. Although a better idea would be to ditch Yahoo
> > altogether and start our own site w/ a similar setup as this
> site. I
> > don't know the how to do it technically or the costs involved,
> but it
> > seems like most people here would be willing to "subscribe" to
> such a
> > site by kicking in some $$, perhaps on an annual basis to keep
> it
> > going. It seems to me that if yahoo is going to start
charging,
> why
> > not start our own and design it as we see fit? Anyone have any
> idea
> > on the costs involved? I'm willing to help out any way I can,
> but I
> > don't have the technical knownledge to get it rolling.
> >
> > Sean
> >
> >
> >
> >
> >
> >
> > To unsubscribe from this group, send an email to:
> >
> >
> >
> >
> > the Yahoo! Terms of
> Service.