Digi Photo Filing

PNG is a web format that was originally developed because compuserve were claiming copyright on the gif format we all know and love.
If you want to keep things lossless, i.e. no compression, save them as tiff files. We (design agency) use these files all the time when we are sending artwork to a printer, simply because they don't lose any quality.
As for arranging things by date, I'm telling you folks, Picassa! You'll never look back.

If you want to keep things lossless, i.e. no compression, save them as tiff files.

PNG gives you lossless compression though. I guess it comes down to whether you would ever need the advanced complex TIFF features or not and how much disk space you have!

Of course astrophotos should be saved as FITS files

Cheers,
~Al

A couple of the lads here that were at Whirlpool '04 showed me their 300Ds, which look sooo impressive.

I have the Fuji FinePix 3000, 3 MP, which is really a glorified pocket zoom. It uses the new xD pic card that they developed with Olympus.

I will have to check out the image storage details over the weekend when I go home to my own pc.
I think it's going to be jpeg though.

Do you guys that use date storage system fill one cd before moving to the next, or is it loads of half-filled ones?

Been day trading all... well... day so I'm a little fatigued and the concept of "lossless compression" is doing my head in. I did use Tiff for a while but some programs I use do not support 16-bit Tiffs.

I guess there must be a lot of redundant data in BMPs for "compression" to work. I'd say it was data stripping rather than compressing. I'll convert a photo in PSP...

Sure enough, BMP 18MB, Tiff 13.8MB and PNG 11.1MB.

I zoomed the three photos to 600% and no difference between either of them ie. no compression.

Ummm, just noticed. The Canon RAW file is just 8.2MB but PSP can't read it though its Open dialogue lists it as an acceptable format.

Right lossless compression 101!

It basically means that you can compress data without loosing any of that data. When you zip up an image file, thats lossless compression. But photoshop cant read a zip file so thats not much use. PNG is one format that builds this compression in, in a graphic format that tools understand.

How does it work? Well heres a basic example of a simple compression algorithm. Say we have the following black and white image (1=black,0=white)

[code:1]
0000000000
0011001100
0000000000
0100000010
0011111100
0000000000
[/code:1]

Its a smiley
It take up 66characters (including the carraidge returns)

It can be represented as:
[code:1]55n11;1:14,15,18,19,35,42,47-52[/code:1]
Which is only 31 characters.

How? It says there are 55 characters with a new row every 11 characters, all are 0 except 1's at 14,15,18.... If you write a program that knows how to read our new format, you can get back the exact same image that you started with.

I'm not going to pretend that I have a clue about how exactly PNG or TIFF handle compression.

A Jpeg for colour images, may introduce smoothing, get rid of unused colours etc. to make the image look more of less similar, but a lot smaller.

Coincidentally Pete Lawrence posted this on uk.sci.astronomy today which may be of use.

Subject: Image viewer
Date: Thu, 16 Dec 2004 11:02:22 +0000
From: Pete Lawrence <pete.lawrence@nospam.co.uk>
Reply-To: pete.lawrence@eyepiecepbl33.co.uk
Newsgroups: uk.sci.astronomy

I posted a link to a good image viewer - Picasa a couple of months
ago. After using the program for a while, although I liked it's
overall performance and style, it's ferretting through all of my
storage for images was a tad annoying.

Basically, what I wanted was a quick, easy viewer that would allow me
to inspect a JPG or TIFF (normally from my camera) quickly and easily.
Ideally it should also be able to easily display certain image EXIF
data quickly and easily (date/time, ISO, exposure, lens focal length,
etc.).

There are solutions to this but they all seem to nearly get there and
then have some irritating quirk that is just.... irritating.

Yesterday I thought I'd struck gold with a program called Fast Stone
Viewer. It's quick and easy to use. Doesn't interrogate your drives
like Picasa and does what it says on the tin basically. When viewing
an image on screen, there's a nice magnifier option that allows you to
specify the size being magnified and the zoom level, just by holding
down the left mouse button.

When you move your mouse to the left or right edge of a full screen
image, various options pop into view. More importantly, the
information that pops up at the right hand edge shows the EXIF data I
want to see... nearly! My heart sank when I realised that the shutter
speed wasn't displaying. 99% there and then falling at the last
fence. I sent an email to the author and amazingly, a couple of hours
and a sample image later, ta dah... it's fixed.

Here's a link to the program if you're interested...

www.faststonesoft.com/DN/FSViewerSetup.exe

[ Details of product at www.faststonesoft.com/FSViewerDetail.htm ~Al]

There is no charge for non-commercial use too!

--
Pete
www.digitalsky.org.uk