Advice on File formats

In article <45d23f30$0$8718$ed2619ec@ptn-nntp-reader02.plus.net>,
Glenis <gh.DeleteThis@here.co.uk> wrote:

> Am I reducing the quality of my photos by initially converting them to
> PNGs?

No. PNG, like TIFF, is lossless. You can change between lossless file
formats with no degradation at all.

--
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Why PNG?
Well, it seems to display fine in browsers I use (IE7, Firefox2 and
Opera), it's lossless & file sizes are relatively small.
What alternative is there to PNG?
TIF isn't supported by browsers at all and file sizes are BIG.

My question regarding quality degradation in converting from JPG to PNG
is to do with my confusion on this 8-bit/16-bit option in PS
(Image-Mode). I'm a little unclear as to how an 8-bit image can have
more than 256 colors.
Perhaps you can point me at a good information source/book.




Little Juice Coupe wrote:
> I doubt there is any loss in quality going from a PNG to TIF. However, I do
> have wonder why PNG. It is pretty much a dead format and isn't even very
> well supported by most browsers. If I was going to choose a format to
> convert my images to from the cameras JPG's it would be TIF. Very wide
> support, offers compression without image data loss and more.
>
> ljc
>
> "Glenis" <gh.TakeThisOut@here.co.uk> wrote in message
> news:45d23f30$0$8718$ed2619ec@ptn-nntp-reader02.plus.net...
>> Hi,
>> My digital camera delivers JPGs (OK, it's not a fancy camera but seems OK
>> for my purposes).
>> When I import them into PS I immediately save them as PNGs for purposes of
>> editing/cropping etc. This seems an OK proposition since:
>> a: Quality isn't degraded following multiple edits/save
>> b. It's a format that's accepted for publishing to the Web (I have a
>> couple of photo websites and a Flickr account)
>> c: File sizes are not too large
>>
>> Another thing I do with my photos is upload them to BonusPrint in order to
>> obtain prints. However, BonusPrint accept only JPG, BMP and TIFF formats
>> so I have to convert the PNGs to TIFFs in order to upload them.
>>
>> My question is this:
>> Am I reducing the quality of my photos by initially converting them to
>> PNGs?. Should I save them as TIFFs?
>> Your suggestions please.
>
>
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In article <45d24de4$0$8719$ed2619ec@ptn-nntp-reader02.plus.net>,
Glenis <gh RemoveThis @here.co.uk> wrote:

> My question regarding quality degradation in converting from JPG to PNG
> is to do with my confusion on this 8-bit/16-bit option in PS
> (Image-Mode). I'm a little unclear as to how an 8-bit image can have
> more than 256 colors.

You are confusing 8 bits per CHANNEL with eight bits per PIXEL.

Eight bits per CHANNEL means eight bits of red, eight bits of green, and
eight bits of blue, for a total of 24 bits per pixel and a total of 16
million colors.

Eight bits per PIXEL means each pixel is made of a total of eight bits,
for a total of 256 colors maximum.

--
Photography, kink, polyamory, shareware, and more: all at
http://www.xeromag.com/franklin.html
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Thanks.

tacit wrote:
> In article <45d24de4$0$8719$ed2619ec@ptn-nntp-reader02.plus.net>,
> Glenis <gh.DeleteThis@here.co.uk> wrote:
>
>> My question regarding quality degradation in converting from JPG to PNG
>> is to do with my confusion on this 8-bit/16-bit option in PS
>> (Image-Mode). I'm a little unclear as to how an 8-bit image can have
>> more than 256 colors.
>
> You are confusing 8 bits per CHANNEL with eight bits per PIXEL.
>
> Eight bits per CHANNEL means eight bits of red, eight bits of green, and
> eight bits of blue, for a total of 24 bits per pixel and a total of 16
> million colors.
>
> Eight bits per PIXEL means each pixel is made of a total of eight bits,
> for a total of 256 colors maximum.
>
 >> Stay informed about: Advice on File formats 

Well, Adobe is moving away from PSD. They don't plan to end support for it,
but they do encourage people to move to TIF that is the format that they are
developing more strongly now (this according to posts from Adobe personel on
the Adobe user forums).

The problem with PNG is far few programs support it than do. As I said
Microsoft did a very good job of killing it. Right now it is only a nitch
format and I don't know about anyone else I am not about to store my images
in a nitch format.

The other issue with PNG besides the transparency in browsers comes in to
play with color management. PNG doesn't do it well and many programs don't
support that well.

There is a reason why most professionals use TIF for both printing and
storage. As far as compression with TIF, I don't find it makes a whole lot
of difference and not all programs (most old, shareware, freeware program)
don't support it. Just like very few programs support TIF files with layers.
But, flattened plain old TIF files are a much better archiving option than
PNG. Show me a professional photographer that saves in PNG and I will show
you a photographer that isn't professional. Show me a printer (pre-press
hear) that accepts images in PNG and I will show you a not so hot printer.

The fact remains you will be able to read TIF files for far longer in to the
future than you will PNG. The only other format that I think has this kind
of life potental is JPG. And, because of its lossy nature is not someting I
would save my images to. I have no problem archiving my cameras JPGs as JPGs
becaue if I need to work on them I will save them as TIF while I do so and
would probably not ever take it back to JPG unless it was going back on the
web. But, for archiving without ever resaving JPG is just fine.

ljc
 >> Stay informed about: Advice on File formats 

On Tue, 13 Feb 2007 22:44:01 +0000, Glenis <gh.RemoveThis@here.co.uk> wrote:


>My question is this:
>Am I reducing the quality of my photos by initially converting them to
>PNGs?. Should I save them as TIFFs?

PNGs are lossless, as are most TIFF formats. So PNGs
will not reduce your quality. See also:

http://www.ransen.com/Articles/Formats/Image-Formats.htm


Easy to use graphics effects:
http://www.ransen.com/
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On Tue, 13 Feb 2007 15:25:39 -0800, "Little Juice Coupe"
<nospam.RemoveThis@nospam.com> wrote:

>I doubt there is any loss in quality going from a PNG to TIF. However, I do
>have wonder why PNG. It is pretty much a dead format and isn't even very
>well supported by most browsers. If I was going to choose a format to
>convert my images to from the cameras JPG's it would be TIF. Very wide
>support, offers compression without image data loss and more.

Which browsers support TIF?


Easy to use graphics effects:
http://www.ransen.com/
 >> Stay informed about: Advice on File formats 

Nothing was said about the web in the OP except as a side note and not as
the main reason he was converting his JPGs to PNG.

ljc


"Owen Ransen" <willy.TakeThisOut@wonker.com> wrote in message
news:d6q6t2164em841boi1dc2nm3ght33f18es@4ax.com...
> On Tue, 13 Feb 2007 15:25:39 -0800, "Little Juice Coupe"
> <nospam.TakeThisOut@nospam.com> wrote:
>
>>I doubt there is any loss in quality going from a PNG to TIF. However, I
>>do
>>have wonder why PNG. It is pretty much a dead format and isn't even very
>>well supported by most browsers. If I was going to choose a format to
>>convert my images to from the cameras JPG's it would be TIF. Very wide
>>support, offers compression without image data loss and more.
>
> Which browsers support TIF?
>
>
> Easy to use graphics effects:
> http://www.ransen.com/
 >> Stay informed about: Advice on File formats 

Yeah, thanks for that.
Being fairly new at this, I was just wondering if I had missed the obvious.
However, it seems to me that PNGs, being lossless and supported by the
main Browsers is a pretty good format with which to save images
(although I was a little surprised by the comment by
Little Juice Coupe
> It is pretty much a dead format and isn't even very
> well supported by most browsers.
If PNG is 'pretty much dead' then what's the alternative?
JPG is maybe ubiquitous but it's lossy and I don't like the sound of
lossy at all.
TIFF (as far as I can discover) is a pretty old format and I can see no
good reason for using it. OK, it's lossless but it produces BIG files,
is not compatible with Browsers and if one uses Photoshop then you may
as well stick to PSD for Layers etc.
But for archiving purposes I'm not too sure which format will be the best.





Owen Ransen wrote:
> On Tue, 13 Feb 2007 22:44:01 +0000, Glenis <gh.RemoveThis@here.co.uk> wrote:
>
>
>> My question is this:
>> Am I reducing the quality of my photos by initially converting them to
>> PNGs?. Should I save them as TIFFs?
>
> PNGs are lossless, as are most TIFF formats. So PNGs
> will not reduce your quality. See also:
>
> http://www.ransen.com/Articles/Formats/Image-Formats.htm
>
>
> Easy to use graphics effects:
> http://www.ransen.com/
 >> Stay informed about: Advice on File formats 

That is the problem. Microsoft did a great job of ensuring the PNG would
never be widely adopted and it isn't. Sure most programs will save it but
few browsers full support the format. The web has two major image formats
like it or not and those a JPG and GIF.

Your original post only mentioned the web as a side note. It seemed that you
were more interested in a format that wasn't lossy to store your digital
camera images as and that format is TIF. If you need to put them on the web
you are most likely going to have to resize them down anyways so PNG isn't
really a benefit.

There is also no guarantee that PNG will be supported in a few years. TIF
will be since Adobe owns and controls it.

ljc


"Glenis" <gh.TakeThisOut@here.co.uk> wrote in message
news:45d397ad$0$8719$ed2619ec@ptn-nntp-reader02.plus.net...
> Yeah, thanks for that.
> Being fairly new at this, I was just wondering if I had missed the
> obvious.
> However, it seems to me that PNGs, being lossless and supported by the
> main Browsers is a pretty good format with which to save images (although
> I was a little surprised by the comment by
> Little Juice Coupe
>> It is pretty much a dead format and isn't even very well supported by
>> most browsers.
> If PNG is 'pretty much dead' then what's the alternative?
> JPG is maybe ubiquitous but it's lossy and I don't like the sound of lossy
> at all.
> TIFF (as far as I can discover) is a pretty old format and I can see no
> good reason for using it. OK, it's lossless but it produces BIG files, is
> not compatible with Browsers and if one uses Photoshop then you may as
> well stick to PSD for Layers etc.
> But for archiving purposes I'm not too sure which format will be the best.
>
>
>
>
>
> Owen Ransen wrote:
>> On Tue, 13 Feb 2007 22:44:01 +0000, Glenis <gh.TakeThisOut@here.co.uk> wrote:
>>
>>
>>> My question is this:
>>> Am I reducing the quality of my photos by initially converting them to
>>> PNGs?. Should I save them as TIFFs?
>>
>> PNGs are lossless, as are most TIFF formats. So PNGs
>> will not reduce your quality. See also:
>>
>> http://www.ransen.com/Articles/Formats/Image-Formats.htm
>>
>>
>> Easy to use graphics effects:
>> http://www.ransen.com/
 >> Stay informed about: Advice on File formats 

Well, Web compatibility was one of the reasons for my choosing PNG.
See:
> When I import them into PS I immediately save them as PNGs for purposes of editing/cropping etc. This seems an OK proposition since:
> a: Quality isn't degraded following multiple edits/save
> b. It's a format that's accepted for publishing to the Web (I have a couple of photo websites and a Flickr account)
> c: File sizes are not too large
The only PNG issues I've heard of re the Web is Transparency, which
doesn't bother me.
You suggest that TIFF will always be supported since Adobe owns/controls
it. Isn't that also the case with PSD? (smaller file sizes).
What about compressed TIFF (LZW)? Apart from file size, what is the
difference?

Little Juice Coupe wrote:
> That is the problem. Microsoft did a great job of ensuring the PNG would
> never be widely adopted and it isn't. Sure most programs will save it but
> few browsers full support the format. The web has two major image formats
> like it or not and those a JPG and GIF.
>
> Your original post only mentioned the web as a side note. It seemed that you
> were more interested in a format that wasn't lossy to store your digital
> camera images as and that format is TIF. If you need to put them on the web
> you are most likely going to have to resize them down anyways so PNG isn't
> really a benefit.
>
> There is also no guarantee that PNG will be supported in a few years. TIF
> will be since Adobe owns and controls it.
>
> ljc
>
>
> "Glenis" <gh RemoveThis @here.co.uk> wrote in message
> news:45d397ad$0$8719$ed2619ec@ptn-nntp-reader02.plus.net...
>> Yeah, thanks for that.
>> Being fairly new at this, I was just wondering if I had missed the
>> obvious.
>> However, it seems to me that PNGs, being lossless and supported by the
>> main Browsers is a pretty good format with which to save images (although
>> I was a little surprised by the comment by
>> Little Juice Coupe
>>> It is pretty much a dead format and isn't even very well supported by
>>> most browsers.
>> If PNG is 'pretty much dead' then what's the alternative?
>> JPG is maybe ubiquitous but it's lossy and I don't like the sound of lossy
>> at all.
>> TIFF (as far as I can discover) is a pretty old format and I can see no
>> good reason for using it. OK, it's lossless but it produces BIG files, is
>> not compatible with Browsers and if one uses Photoshop then you may as
>> well stick to PSD for Layers etc.
>> But for archiving purposes I'm not too sure which format will be the best.
>>
>>
>>
>>
>>
>> Owen Ransen wrote:
>>> On Tue, 13 Feb 2007 22:44:01 +0000, Glenis <gh RemoveThis @here.co.uk> wrote:
>>>
>>>
>>>> My question is this:
>>>> Am I reducing the quality of my photos by initially converting them to
>>>> PNGs?. Should I save them as TIFFs?
>>> PNGs are lossless, as are most TIFF formats. So PNGs
>>> will not reduce your quality. See also:
>>>
>>> http://www.ransen.com/Articles/Formats/Image-Formats.htm
>>>
>>>
>>> Easy to use graphics effects:
>>> http://www.ransen.com/
>
>
 >> Stay informed about: Advice on File formats 

Little Juice Coupe wrote:
> Well, Adobe is moving away from PSD. They don't plan to end support for it,
> but they do encourage people to move to TIF that is the format that they are
> developing more strongly now (this according to posts from Adobe personel on
> the Adobe user forums).

Can you give us URLs to those posts? I find it hard to believe that
Adobe is moving to TIFF. DNG, perhaps, because it is an extension of
TIFF, but TIFF itself?
 >> Stay informed about: Advice on File formats 

On Thu, 15 Feb 2007 09:51:02 -0600, JJ <john.RemoveThis@nowhere.net> wrote:

>Little Juice Coupe wrote:
>> Well, Adobe is moving away from PSD. They don't plan to end support for it,
>> but they do encourage people to move to TIF that is the format that they are
>> developing more strongly now (this according to posts from Adobe personel on
>> the Adobe user forums).
>
>Can you give us URLs to those posts? I find it hard to believe that
>Adobe is moving to TIFF. DNG, perhaps, because it is an extension of
>TIFF, but TIFF itself?

http://www.adobe.com/cfusion/webforums/forum/messageview.cfm?catid=593...readid=
or
http://tinyurl.com/2k975t

Haven't seen anything else on the topic, though.
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The Magazine of Folk and World Music
www.dirtylinen.com
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