Archived posting to the Leica Users Group, 2005/02/11

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] Can you really JPEG a JPEG?
From: corkflor at iol.ie (Alex Hurst)
Date: Fri Feb 11 12:20:54 2005
References: <2b.6c8e6565.2f3d89ea@aol.com> <005101c51060$c20eecb0$833b6d18@ted>

Hi all.

I've just posted some shots of our recent Barcelona visit at:

http://www.iol.ie/~corkflor/

As I was getting overwhelmed by proof prints, I instructed my 
friendly photo processors to simply develop the film and provide a CD 
with a reference print. This means I can review what I've got very 
quickly on the Mac, find the average 3 or 4 keepers per roll, and 
scan the relevant negs to produce decent prints.

In other words, my ancient film Leicas are being used in a more 
direct digital way, and my flatbed scanner won't get much more use.

But to prepare shots for the Web, I simply took the hi-res versions 
on disc, cropped, corrected and re-sized them, and then saved them as 
a small 'lossy' JPEG.

The original hi-res files are around 700K, which compares poorly with 
the 20Mb+ available from a neg. But for the Net where you're 
publishing at around 90 p.p.i., this is not such a problem.

My question is this: the hi-res disk files have a JPEG (jpg) handle, 
and received wisdom is that quality deteriorates rapidly if you try 
to re-compress an existing JPEG. So are these hi-res files really 
JPEGs?

I took a deep breath and saved the adjusted and resized PS files as 
small JPEGs, and, as you can see, the results seem pretty good - in 
fact more or less on a par with what I would expect from a Net-ready 
JPEG  where the original data came from film. Am I missing something 
here?

All explanations gratefully received.

Anyway, as it works for me, this route will save an an awful lot of 
trees, not to mention reducing my processing bills drastically.

Best

Alex






-- 
Alex Hurst
Waterfall
Nr. Cork
Ireland

Tel: +353 214 543 328 (H)
        +353 214 270 907 (W)

Fax: +353 214 271 248
email: corkflor@iol.ie
Also: corkflor.2@virgin.net (when in the UK, which isn't often)
Home website: http://www.iol.ie/~corkflor/
Business website: http://www.corkflorists.com/

Pretty Good Privacy (PGP) public key available at:
http://pgpkeys.mit.edu:11371
ID: 0x5BB72019

Replies: Reply from aaron.sandler at duke.edu (Aaron Sandler) ([Leica] Can you really JPEG a JPEG?)
In reply to: Message from SonC at aol.com (SonC@aol.com) ([Leica] your dog and my remarks)
Message from tedgrant at shaw.ca (Ted Grant) ([Leica] WAS: and my remarks NOW: Sympathy.)