Re: Raw picture reduction



Rowland McDonnell <real-address-in-sig@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
Woody <usenet@xxxxxxxxxxxxxx> wrote:

:
[snip]
.

<puzzled> TIFF permits compression of any sort, you know.

I know. But when uncompressed to a non compressed format, the
pictures
are huge. 25MB as a tiff, 8MB as a CR2, 1MB as a jpeg

25MB ain't huge. Big, not huge. 25MB was `typical' for image files
I
saw in use in publishing back in the mid 1990s. BIG ones were, erm,
big...

In this context, it is big. I am not running a big printing press.

I've got graphics files in the hundreds of megabytes. I'm not running
a
big printing press either. We both have gigabytes of RAM and (okay,
not
many) terabytes of disc space. 25MB is peanuts.

Again, not in this context. I had 3gb left on a 320gb disk.

The whole issue was that these images (at 8MB) were way larger than
needed

[snip]

Seems so, but apart from the colour cast of the output (which I
assume
was not jpeg related), the 1MB jpeg2000 and 800k jpeg looked
pretty
identical in other software.

The only way that can work - assuming you're not half blind and/or
viewing at some stupidly shrunken scale and so on - is if the JPEG
is of
such high quality (i.e., low compression factor) that you're
seeing
no
compression defects at all.

I am seeing no noticable compression defects, ie, I can see it is
not
identical but I am getting no patterns.

Umm. If you can see differences, then you are seeing compression
defects.

Ok, well in that case both jpeg and jpeg2000 are defective by design,
as
they appear immediately.

Not at all - the *point* is to introduce defects, so as to save on
space. The other point is that the defects introduced by JPEG2000 are
less nasty than those introduced by original JPEG.

But failed to replicate that in my tests

[snip]

JPEG2000 is `JPEG done properly' - it *CANNOT* produce a lower
quality
size for size than original JPEG for any image type I can think of,
assuming the compressor's not broken. The original JPEG format was
a
bit of a bodge, and it took a while for someone to figure out how it
should have been done. And *that* is what JPEG2000 is.

Maybe. Regardless though, I can look at the technology and see the
differences, but it doesn't help me as it doesn't change the outcome
of
my test.

Knowing that jpeg 2000 should produce a better image, doesn't change
the
fact that here, it doesn't.

<puzzled> It *does* produce a better image, size for size. If you're
not seeing that, then something is wrong.


jpeg 2000 certainly produces a less troubling
degredation at higher compression ratios (on smaller pics, these
are
all
3500 x 2900) where the jpeg comes up with the cell patterning,
allthough
at full compression, where the jpeg is badly squarey, the jpeg2000
has a
huge line through it

Huh? What what what? Go on, email me with this one, I'd like to
see
it.

Ok. I think it is something to do with block size, as there was a
control for that

JPEG2000 doesn't use blocks. It works on wavelets, which is `doing
the
job properly'.

Well, there was a control that mentioned the word block and was set to
1024

[snip]

JPEG always gives real loss of quality - in all cases when I've
tried
it. JPEG2000 does not.

Maybe, but in my tests I couldn't see that difference, and all that
matters in this case is my subjective opinion.

If you're not seeing an improvement, then you either have a liking for
JPEG blocky artifacts, or you're mad, or your eyes are really bizarre,
or (and I suspect this is the case) there's something not working as
it
ought to with the machinery.

As I said, I backed the compression off before the jpeg got blocky


Please note: I am *always* deeply sceptical about anything new on
computers (and most other things, for that matter). You've surely
noticed?

I tried JPEG2000 with my `Ho yus, what's all this, then? More
bollocks?' hat on and got a hell of a shock.

I am the opposite in this case, I expected it to be better.


Incidently I never found a way to change the files in place, I did
a
find copy for CR2 files in the terminal with:

find . -name *.CR2 -exec cp {} /Volumes/BACKUP/cr2/iphoto \;

Brave man... I'd've used EasyFind myself.

Would that work on a finder bundle such as iPhoto?

Can do if you tick the right boxes. Package contents is what you want
to search. What exactly is a bundle these days? I really hate
Apple's
way of recycling the jargon terms it invents.

Cocoa used to be a full-on programming environment long before MacOS
X.
It was a graphical programming language for young childen - from
Apple,
no less. Can I find one single reference to it on the Web these days?
Nope.

I have never heard of that before. Cocoa became cocoa after the
developer release of rhapsody, what was to become osx.

You are not confusing this with smalltalk were you? Objective c which is
the language that is generally used to create cocoa interfaces has a
history that draws some techniques from smalltalk, although is very
dissimilar in other ways

Smalltalk was made for children to be able to control computers
originally, and is a nice language for teaching. I do believe that you
would gain more from teaching a child smalltalk than office but the
crapness of computer science education (rather than IT) is another
matter



--
Woody
.



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