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lzw or lossless jpg?

 
 
Ken Weitzel
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      09-11-2004

Hi...

The peter principle is working here... (things
expand to fill the space available for their storage)

Wondering if anyone has any opinions on the relative
merits of lossless jpg versus lzw compressed tiff's
for archiving?

Thanks, and take care.

Ken

 
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Gadgets
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      09-11-2004
jpgs are more widely used, some progs don't like LZW tiff or print much
slower with LZW on, data corruption with a jpg will render all pixels after
the corruption point as garbled, with tiff it may only be a few lines...

Cheers, Jason (remove ... to reply)
Video & Gaming: http://gadgetaus.com
 
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Kevin McMurtrie
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      09-11-2004
In article <(E-Mail Removed)>,
"Gadgets" <info@gadgetaus..com> wrote:

> jpgs are more widely used, some progs don't like LZW tiff or print much
> slower with LZW on, data corruption with a jpg will render all pixels after
> the corruption point as garbled, with tiff it may only be a few lines...
>
> Cheers, Jason (remove ... to reply)
> Video & Gaming: http://gadgetaus.com


An LZW tiff will suffer as much damage as a JPEG. The problem is that
the corruption is amplified by the compression.
 
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Eric Gill
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      09-11-2004
Kevin McMurtrie <(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> In article <(E-Mail Removed)>,
> "Gadgets" <info@gadgetaus..com> wrote:
>
>> jpgs are more widely used, some progs don't like LZW tiff or print
>> much slower with LZW on, data corruption with a jpg will render all
>> pixels after the corruption point as garbled, with tiff it may only
>> be a few lines...
>>
>> Cheers, Jason (remove ... to reply)
>> Video & Gaming: http://gadgetaus.com

>
> An LZW tiff will suffer as much damage as a JPEG.


Well, that explains why LZW is considered "lossless."

I'm not sure how. Perhaps you'd like to explain?

> The problem is that
> the corruption is amplified by the compression.


In a JPEG, the "corruption" is caused by the compression.

I think you are very confused.

 
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Trev
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      09-11-2004

"Gadgets" <info@gadgetaus..com> wrote in message
news:(E-Mail Removed)...
> jpgs are more widely used, some progs don't like LZW tiff or print much
> slower with LZW on, data corruption with a jpg will render all pixels
> after
> the corruption point as garbled, with tiff it may only be a few lines...
>
> Cheers, Jason (remove ... to reply)
> Video & Gaming: http://gadgetaus.com

The opposite of above LZW tiff has been around for years most Graphic
editors can handle them. Lossless Jpeg Is newish and only the high end
programs accommodate them. But the real question is if you archive them now
Which is most likely to be still around in years to come, and has not
changed so that it no longer opens your image.


 
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Grim
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      09-11-2004
"Eric Gill" <(E-Mail Removed)> wrote
> Kevin McMurtrie <(E-Mail Removed)> wrote in
> news:(E-Mail Removed):
>
> > In article <(E-Mail Removed)>,
> > "Gadgets" <info@gadgetaus..com> wrote:
> >
> >> jpgs are more widely used, some progs don't like LZW tiff or print
> >> much slower with LZW on, data corruption with a jpg will render all
> >> pixels after the corruption point as garbled, with tiff it may only
> >> be a few lines...
> >>
> >> Cheers, Jason (remove ... to reply)
> >> Video & Gaming: http://gadgetaus.com

> >
> > An LZW tiff will suffer as much damage as a JPEG.

>
> Well, that explains why LZW is considered "lossless."
>
> I'm not sure how. Perhaps you'd like to explain?


Are you intentionally trying to be dense?

"Lossless" compression refers to no loss of detail when the image is
compressed. LZW does this; JPEG does not. Of course you'll likely lose
detail if the file is corrupted! That has nothing to do with lossless
compression, other than losing X bytes of a compressed file will likely lose
more information than X bytes of an uncompressed file.

> > The problem is that
> > the corruption is amplified by the compression.

>
> In a JPEG, the "corruption" is caused by the compression.
>
> I think you are very confused.


I think you are.


 
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Jim Townsend
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      09-11-2004
Ken Weitzel wrote:

>
> Hi...
>
> The peter principle is working here... (things
> expand to fill the space available for their storage)
>
> Wondering if anyone has any opinions on the relative
> merits of lossless jpg versus lzw compressed tiff's
> for archiving?


Lossless JPEG isn't well supported by the standard
crop of image editors and viewers.

I've never used it, but it would seem there really wasn't
much of an advantage over LZW TIFF.

The noteable thing about JPEG is the fact it *is* lossy.
This allows for incredible compression.

Take away the loss and I can't see JPEG being any better
than LZW TIFF. (Not unless they've come up with a better
algorithm than that developed by Lempel Ziv and Welch.




 
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Gadgets
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      09-11-2004
Not talking about lossy artefacting, talking about the effects of data
corruption, particularly in a long term storage situation...

Cheers, Jason (remove ... to reply)
Video & Gaming: http://gadgetaus.com
 
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Bruce Murphy
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      09-11-2004
"Gadgets" <info@gadgetaus..com> writes:

> Not talking about lossy artefacting, talking about the effects of data
> corruption, particularly in a long term storage situation...


Frankly, virtually anything you're goingto use for storage will see
large catastrophic data loss anyway.

B>
 
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spodosaurus
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      09-11-2004
Grim wrote:
> "Eric Gill" <(E-Mail Removed)> wrote
>
>>Kevin McMurtrie <(E-Mail Removed)> wrote in
>>news:(E-Mail Removed):
>>
>>
>>>In article <(E-Mail Removed)>,
>>> "Gadgets" <info@gadgetaus..com> wrote:
>>>
>>>
>>>>jpgs are more widely used, some progs don't like LZW tiff or print
>>>>much slower with LZW on, data corruption with a jpg will render all
>>>>pixels after the corruption point as garbled, with tiff it may only
>>>>be a few lines...
>>>>
>>>>Cheers, Jason (remove ... to reply)
>>>>Video & Gaming: http://gadgetaus.com
>>>
>>>An LZW tiff will suffer as much damage as a JPEG.

>>
>>Well, that explains why LZW is considered "lossless."
>>
>>I'm not sure how. Perhaps you'd like to explain?

>
>
> Are you intentionally trying to be dense?
>
> "Lossless" compression refers to no loss of detail when the image is
> compressed.


No **** dude, he was being sarcastic The earlier poster suggested
that there was loss.

> LZW does this; JPEG does not.


The original poster was not talking about regular jpg, he specifically
stated lossless jpg, which others in this thread do not appear to be
familiar with.


> Of course you'll likely lose
> detail if the file is corrupted! That has nothing to do with lossless
> compression, other than losing X bytes of a compressed file will likely lose
> more information than X bytes of an uncompressed file.
>
>
>>> The problem is that
>>>the corruption is amplified by the compression.

>>
>>In a JPEG, the "corruption" is caused by the compression.
>>
>>I think you are very confused.

>
>
> I think you are.
>
>



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