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How Can Tiff Converted From RAW be so large?

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Anonymous
February 3, 2005 1:32:14 PM

Archived from groups: rec.photo.digital (More info?)

Recently I began experimenting with RAW images instead of the usual .jpeg
format as my primary means of recording digital images. I like the
flexibility and control of RAW but as most of you know they must be
converted to something else to be used. I'm used to 5 or 6 meg size .jpegs.
The TIFF file size of converted RAWS is very close to 50 megs a picture. I
don't know if I'm doing something wrong in the conversion or if the 50 meg
size is normal. Also, when viewed in Photoshop the image size (physical) is
approximately 6" x 10" for a 50 meg TIFF. Sort of hard to believe for a file
size that big. Any answers or tips would be greatly appreciated.

Bob
Anonymous
February 3, 2005 1:32:15 PM

Archived from groups: rec.photo.digital (More info?)

On Thu, 03 Feb 2005 10:32:14 GMT, in rec.photo.digital "Bob Krecak"
<rkrecak@wi.rr.com> wrote:

>Recently I began experimenting with RAW images instead of the usual .jpeg
>format as my primary means of recording digital images. I like the
>flexibility and control of RAW but as most of you know they must be
>converted to something else to be used. I'm used to 5 or 6 meg size .jpegs.
>The TIFF file size of converted RAWS is very close to 50 megs a picture. I
>don't know if I'm doing something wrong in the conversion or if the 50 meg
>size is normal. Also, when viewed in Photoshop the image size (physical) is
>approximately 6" x 10" for a 50 meg TIFF. Sort of hard to believe for a file
>size that big. Any answers or tips would be greatly appreciated.

Sounds like an uncompressed 16-bit tiff, compared to 8-bit compressed jpeg.
----------
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://edwardgruf.com/Digital_Photography/General/index...
Anonymous
February 3, 2005 1:32:15 PM

Archived from groups: rec.photo.digital (More info?)

Consider a 8.2 MPixel image
RAW is 12-bits/pixel which then gets huffman compressed into 8.2MBytes
(+/- 33% compression or 50% expansion)
TIFF-16 is 16 bits per color per pixel or 48-bits per pixel or 6 bytes
per pixel.
6 bytes/pixel * 8.2 Million Pixels = 48 MBytes.

This is a 6X increase in size due to the huffman compression of the RAW
data.

Mitch
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Anonymous
February 3, 2005 1:53:50 PM

Archived from groups: rec.photo.digital (More info?)

Bob Krecak wrote:
> Recently I began experimenting with RAW images instead of the usual
> .jpeg format as my primary means of recording digital images. I like
> the flexibility and control of RAW but as most of you know they must
> be converted to something else to be used. I'm used to 5 or 6 meg
> size .jpegs. The TIFF file size of converted RAWS is very close to 50
> megs a picture. I don't know if I'm doing something wrong in the
> conversion or if the 50 meg size is normal. Also, when viewed in
> Photoshop the image size (physical) is approximately 6" x 10" for a
> 50 meg TIFF. Sort of hard to believe for a file size that big. Any
> answers or tips would be greatly appreciated.

RAW - would be typically 12 bits per sensor site

TIFF - might be 16-bits per pixel for each of three channels - so 48 bits
per sensor site.

At worst, I would only expect around a 4X increase in file size.

David
Anonymous
February 3, 2005 2:17:07 PM

Archived from groups: rec.photo.digital (More info?)

"Bob Krecak" <rkrecak@wi.rr.com> wrote in message
news:o 4nMd.5892$0h5.2315@twister.rdc-kc.rr.com...
> Recently I began experimenting with RAW images instead of the usual .jpeg
> format as my primary means of recording digital images. I like the
> flexibility and control of RAW but as most of you know they must be
> converted to something else to be used. I'm used to 5 or 6 meg size
> .jpegs.
> The TIFF file size of converted RAWS is very close to 50 megs a picture. I
> don't know if I'm doing something wrong in the conversion or if the 50 meg
> size is normal. Also, when viewed in Photoshop the image size (physical)
> is
> approximately 6" x 10" for a 50 meg TIFF. Sort of hard to believe for a
> file
> size that big. Any answers or tips would be greatly appreciated.

How about just not using TIFF ?

Personally, I shoot in RAW and then import the RAW directly into Photoshop.
I leave the RAW file as my "digital negative" and then output the final
image from Photoshop to .jpg for printing or web. I then also save the
Photoshop format file if I have had to do a lot of editing to the RAW.
February 3, 2005 2:17:08 PM

Archived from groups: rec.photo.digital (More info?)

adm wrote:
>
> How about just not using TIFF ?
>
> Personally, I shoot in RAW and then import the RAW directly into Photoshop.
> I leave the RAW file as my "digital negative" and then output the final
> image from Photoshop to .jpg for printing or web. I then also save the
> Photoshop format file if I have had to do a lot of editing to the RAW.


Yep, once you do the editing there is minimal benefit in keeping tif. It
is ideal but... 16 bit is only needed if you plan to do heavy
manipulations. It is still perhaps worth going through the exercise
though to get sharper images even if you end up using the default
enhancements it's likely to work better in software than the in-camera
enhancements which are forced to be very fast and not ideal.

PNG is another format to try though you will lose EXIF camera info.
Anonymous
February 3, 2005 2:28:25 PM

Archived from groups: rec.photo.digital (More info?)

In message <36ee5uF51gorhU1@individual.net>,
"David J Taylor" <david-taylor@invalid.com> wrote:

>RAW - would be typically 12 bits per sensor site
>
>TIFF - might be 16-bits per pixel for each of three channels - so 48 bits
>per sensor site.
>
>At worst, I would only expect around a 4X increase in file size.

In many file formats, RAW files losslessly compress to 7 or 8 bits per
pixel, for low ISO images, and sometimes far less if the image is nearly
all the same tone.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
February 3, 2005 3:28:40 PM

Archived from groups: rec.photo.digital (More info?)

>From: "Bob Krecak" rkrecak@wi.rr.com
>Date: 2/3/2005 4:32 AM Central Standard Time

>Recently I began experimenting with RAW images instead of the usual .jpeg
>format as my primary means of recording digital images. I like the
>flexibility and control of RAW but as most of you know they must be
>converted to something else to be used. I'm used to 5 or 6 meg size .jpegs.
>The TIFF file size of converted RAWS is very close to 50 megs a picture. I
>don't know if I'm doing something wrong in the conversion or if the 50 meg
>size is normal. Also, when viewed in Photoshop the image size (physical) is
>approximately 6" x 10" for a 50 meg TIFF. Sort of hard to believe for a file
>size that big. Any answers or tips would be greatly appreciated.
>

The Photoshop physical image size is pretty meaningless. PS has a pixels per
inch (ppi) setting. The physical size reported by PS is simply the pixel size
of the photo divided by whatever you have ppi set at. For instance if your
photo is 3000x2000 pixels and ppi in PS is set at 72, PS will show the physical
photo size as 41.67" x 27.78". If you change the ppi to 300, PS will show the
physical size to be 10" x 6.67".

Ron
Anonymous
February 3, 2005 4:58:29 PM

Archived from groups: rec.photo.digital (More info?)

Bob Krecak wrote:

> Recently I began experimenting with RAW images instead of the usual .jpeg
> format as my primary means of recording digital images. I like the
> flexibility and control of RAW but as most of you know they must be
> converted to something else to be used. I'm used to 5 or 6 meg size .jpegs.
> The TIFF file size of converted RAWS is very close to 50 megs a picture. I
> don't know if I'm doing something wrong in the conversion or if the 50 meg
> size is normal. Also, when viewed in Photoshop the image size (physical) is
> approximately 6" x 10" for a 50 meg TIFF. Sort of hard to believe for a file
> size that big. Any answers or tips would be greatly appreciated.

It's normal: the TIFF format is bigger :) 

--
chidalgo
February 3, 2005 8:54:15 PM

Archived from groups: rec.photo.digital (More info?)

"Bob Krecak" <rkrecak@wi.rr.com> wrote in message
news:o 4nMd.5892$0h5.2315@twister.rdc-kc.rr.com...
> Recently I began experimenting with RAW images instead of the usual .jpeg
> format as my primary means of recording digital images. I like the
> flexibility and control of RAW but as most of you know they must be
> converted to something else to be used. I'm used to 5 or 6 meg size
..jpegs.
> The TIFF file size of converted RAWS is very close to 50 megs a picture. I
> don't know if I'm doing something wrong in the conversion or if the 50 meg
> size is normal. Also, when viewed in Photoshop the image size (physical)
is
> approximately 6" x 10" for a 50 meg TIFF. Sort of hard to believe for a
file
> size that big. Any answers or tips would be greatly appreciated.
>
> Bob
>
>
In addition to what others have said, it could be that your camera only
inputs the data from the sensors into a RAW file; i. e. it has not been
demosaiced.
As for the comment about the image size, that is controlled by the pixels
per inch setting.
Jim
February 4, 2005 12:52:46 AM

Archived from groups: rec.photo.digital (More info?)

On Thu, 03 Feb 2005 10:32:14 GMT, "Bob Krecak" <rkrecak@wi.rr.com> wrote:

>Recently I began experimenting with RAW images instead of the usual .jpeg
>format as my primary means of recording digital images. I like the
>flexibility and control of RAW but as most of you know they must be
>converted to something else to be used. I'm used to 5 or 6 meg size .jpegs.
>The TIFF file size of converted RAWS is very close to 50 megs a picture. I
>don't know if I'm doing something wrong in the conversion or if the 50 meg
>size is normal. Also, when viewed in Photoshop the image size (physical) is
>approximately 6" x 10" for a 50 meg TIFF. Sort of hard to believe for a file
>size that big. Any answers or tips would be greatly appreciated.
>
>Bob
>

I'd guess you have an 8mpx camera? 8 mpx will convert to a 24MB tif at 3 bytes
per pixel using 8 bit colour depth (one byte per colour channel per pixel). At
16 bit colour depth it will be twice that. So, your 50MB file size makes perfect
sense.

A jpg file uses data compression. This reduces the file size at the cost of
losing some image detail. tif has no compression. Canon RAW, OTOH, uses lossless
compression so an 8mpx image would take about 8MB (depending on the image and
how much detail it contains).

Using RAW makes sense because it preserves every skerric of information picked
up by the sensor. Sure you need tif to process in most editors, though some will
now read and convert RAW files directly. Perhaps the best strategy is to treat
the RAW file as you irreplacable "negative" as it contains *all* the information
in a reasonably compact file. Treat tif as an intermediate stage to be edited
and printed then discarded once you are finished. You can also explore you image
editor's ability to save tif files with compression, in order to reduce the file
size. BTW only 16 bit tif will preserve as much information as RAW - 8-bit
won't.

Whatever you do I'd strongly council against using jpg as anything but an output
format, say for the web. Do not save your precious images in jpg.
Anonymous
February 4, 2005 12:52:47 AM

Archived from groups: rec.photo.digital (More info?)

On Thu, 03 Feb 2005 21:52:46 +1100, DJ <dontemail@optusnet.com.au>
wrote:

>On Thu, 03 Feb 2005 10:32:14 GMT, "Bob Krecak" <rkrecak@wi.rr.com> wrote:
>
>>Recently I began experimenting with RAW images instead of the usual .jpeg
>>format as my primary means of recording digital images. I like the
>>flexibility and control of RAW but as most of you know they must be
>>converted to something else to be used. I'm used to 5 or 6 meg size .jpegs.
>>The TIFF file size of converted RAWS is very close to 50 megs a picture. I
>>don't know if I'm doing something wrong in the conversion or if the 50 meg
>>size is normal. Also, when viewed in Photoshop the image size (physical) is
>>approximately 6" x 10" for a 50 meg TIFF. Sort of hard to believe for a file
>>size that big. Any answers or tips would be greatly appreciated.
>>
>>Bob
>>
>
>I'd guess you have an 8mpx camera? 8 mpx will convert to a 24MB tif at 3 bytes
>per pixel using 8 bit colour depth (one byte per colour channel per pixel). At
>16 bit colour depth it will be twice that. So, your 50MB file size makes perfect
>sense.
>

I have this question also with the Dimage 5 (3.3mpx). If I save as
RAW and process to a TIFF using Minolta's software I get an 18mB file
which is about twice the size that I get if I let the camera save as a
TIFF to start with.

Just curious as to what may have gone missing or is it about using
different colour depth as above?


--
TonyL
Anonymous
February 4, 2005 12:52:48 AM

Archived from groups: rec.photo.digital (More info?)

Note that TIF files can be saved with lossless compression applied - see the
options available in the software you are using to create and save your
TIF's. This type of compression (for example the LZW option) is similar to
the compression used in zip files and does NOT destroy any data. It allows
the file to later be reopened with NO loss of picture quality. Please note,
however, that some applications which import TIF's (word processors or page
layout programs for example) may not be able to properly recognize TIF's
saved with compression applied. In such cases, it is a simple matter to
reopen the file in your photo editor and save a temporary copy in
uncompressed format for use with such programs. Still, this allows you to
keep your archived TIF's in compressed format which greatly reduces storage
space requirements.
Anonymous
February 4, 2005 12:52:48 AM

Archived from groups: rec.photo.digital (More info?)

intothebin@hotmail.com (Tony Lewis) wrote in
news:42021bd9.7845991@news.individual.net:

> On Thu, 03 Feb 2005 21:52:46 +1100, DJ <dontemail@optusnet.com.au>
> wrote:
>
>>On Thu, 03 Feb 2005 10:32:14 GMT, "Bob Krecak" <rkrecak@wi.rr.com>
>>wrote:
>>
>>>Recently I began experimenting with RAW images instead of the usual
>>>.jpeg format as my primary means of recording digital images. I like
>>>the flexibility and control of RAW but as most of you know they must
>>>be converted to something else to be used. I'm used to 5 or 6 meg
>>>size .jpegs. The TIFF file size of converted RAWS is very close to 50
>>>megs a picture. I don't know if I'm doing something wrong in the
>>>conversion or if the 50 meg size is normal. Also, when viewed in
>>>Photoshop the image size (physical) is approximately 6" x 10" for a
>>>50 meg TIFF. Sort of hard to believe for a file size that big. Any
>>>answers or tips would be greatly appreciated.
>>>
>>>Bob
>>>
>>
>>I'd guess you have an 8mpx camera? 8 mpx will convert to a 24MB tif at
>>3 bytes per pixel using 8 bit colour depth (one byte per colour
>>channel per pixel). At 16 bit colour depth it will be twice that. So,
>>your 50MB file size makes perfect sense.
>>
>
> I have this question also with the Dimage 5 (3.3mpx). If I save as
> RAW and process to a TIFF using Minolta's software I get an 18mB file
> which is about twice the size that I get if I let the camera save as a
> TIFF to start with.
>
> Just curious as to what may have gone missing or is it about using
> different colour depth as above?

Sounds like it. Most in-camera processed images are saved out in 8-bit.
Why don't you take test shots both ways and open them in PS to see what
mode each is in?
Anonymous
February 4, 2005 1:21:24 AM

Archived from groups: rec.photo.digital (More info?)

In message <42021bd9.7845991@news.individual.net>,
intothebin@hotmail.com (Tony Lewis) wrote:

>I have this question also with the Dimage 5 (3.3mpx). If I save as
>RAW and process to a TIFF using Minolta's software I get an 18mB file
>which is about twice the size that I get if I let the camera save as a
>TIFF to start with.
>
>Just curious as to what may have gone missing or is it about using
>different colour depth as above?

The 10MB file from the camera is an 8-bit TIFF, and is really not much
better than a 1.5MB high-quality JPEG.

The 18MB file is a 16-bit TIFF and can be manipulated repeatedly in an
editor without posterization artifacts.

For cameras that don't output RAW, 8-bit TIFFs are very inefficient and
only slightly better than highest-quality JPEGs. For cameras that also
produce RAW, the only benefit of 8-bit TIFFs is that they are readily
viewable on any computer, but they contain much less real image data
than the RAW file.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
February 4, 2005 3:26:28 PM

Archived from groups: rec.photo.digital (More info?)

On Thu, 03 Feb 2005 22:21:24 GMT, JPS@no.komm wrote:

>In message <42021bd9.7845991@news.individual.net>,
>intothebin@hotmail.com (Tony Lewis) wrote:
>
>>I have this question also with the Dimage 5 (3.3mpx). If I save as
>>RAW and process to a TIFF using Minolta's software I get an 18mB file
>>which is about twice the size that I get if I let the camera save as a
>>TIFF to start with.
>>
>>Just curious as to what may have gone missing or is it about using
>>different colour depth as above?
>
>The 10MB file from the camera is an 8-bit TIFF, and is really not much
>better than a 1.5MB high-quality JPEG.
>
>The 18MB file is a 16-bit TIFF and can be manipulated repeatedly in an
>editor without posterization artifacts.
>
>For cameras that don't output RAW, 8-bit TIFFs are very inefficient and
>only slightly better than highest-quality JPEGs. For cameras that also
>produce RAW, the only benefit of 8-bit TIFFs is that they are readily
>viewable on any computer, but they contain much less real image data
>than the RAW file.

Many thanks for this very clear explanation. Given the size of the
RAW is smaller than camera produced TIFF's I can see myself doing a
lot more off-camera RAW->TIFF(->JPEG) work in future.


--
TonyL
!