I agree that for web use Jpg may very well be a necessity and that
sharpening just before converting to a given level of compression when
converting to JPG may be the best way to go since in most case those
downloading the web image will not be resizing the image for serious uses
and/or then
Tony writes:
This is only a minor sharpening to restore
the sharpness of the original ...
Sharpness cannot be restored, it can only be simulated. Sharpening causes
deterioration in image quality, so it should be avoided until the image is
about to be prepared for a specific use. I archive
Laurie writes:
Theoretically maybe ...
All images are bitmaps at the time of sharpening. The format in which they
were or will be stored is irrelevant.
Additionally, all sharpening degrades an image, so it should not be carried
out for images that are being archived, as you may need the
Ken writes:
But when printing it's best to go direct from
the TIFF isn't it?
It doesn't matter.
When producing for the web, yes, I go to jpeg
and then sharpen.
You can't. All images are bitmaps while you are manipulating them. JPEG
and TIFF are just file formats.
Preston writes:
One pre-press expert in my area recommends
ColorMatchRGB instead of Adobe98 for pre-press
work. Is this a Mac vs. PC thing?
No, it is more of a printed-on-paper vs. electronic-display thing.
ColorMatchRGB is designed for print, whereas Adobe98 is for more general use
and has
Ken writes:
... but could someone offer a technical explanation
of why sharpening has so much more visible effect
on jpegs as opposed to TIFFs?
It doesn't.
Unsubscribe by mail to [EMAIL PROTECTED], with
Laurie writes:
... how does one sharpen between the conversion stage
and the compression stage?
One does not.
There seems to be a widespread misconception here. While you are editing an
image, it _does not have_ a format; it isn't JPEG, or TIFF, or anything
else. The image is stored on a
Maris writes:
Sharpening at that point was what I was
suggesting, before saving as a more-compressed JPG.
Sharpening permanently diminishes the quality of an image, and it also makes
the resulting JPEG file somewhat larger.
Maris writes:
True enough, but if the image requires sharpening?
You cannot know if an image will require sharpening or not until you know
how the image will actually be used.
I would think it better to convert to JPG and
then sharpen rather than sharpen in TIFF and then
convert.
Neither
Laurie writes:
For other than web work, some have suggested
that saving an image for archival purposes as a LWZ
compressed TIFF file is the best way to go
for compression without artifacts.
True--TIFF is lossless, and so it does not create artifacts.
However, if you save an image as JPEG
CCDs, in and of them selves, don't have anything to do with number of
bits,
as they are analog devices, but their dynamic range does... If the CCD
has
a dynamic range of 5000:1, it will require a 13 bit A/D to be able to
extract the full dynamic range of the CCD.
Regards,
Austin
Anthony writes ...
Laurie writes:
... how does one sharpen between the conversion stage
and the compression stage?
One does not.
There seems to be a widespread misconception here. While
you are editing an image, it _does not have_ a format;
it isn't JPEG, or TIFF, or anything else.
Peter,
CCDs, in and of them selves, don't have anything to do with number of
bits,
as they are analog devices, but their dynamic range does... If the CCD
has
a dynamic range of 5000:1, it will require a 13 bit A/D to be able to
extract the full dynamic range of the CCD.
Regards,
A friend with a Coolscan IV and a very slow PC wants a faster PC.
For a similar price I can build at fast 1700 Athlon, 512 meg RAM with a
separate 32 Meg video card PC or he can purchase a similar spec machine
ready built with onboard video that shares the system RAM.
The cost of machines ready
I support Ken. I'm currently scanning a large number of rolls of negative
film. They are just 10x.6.67 inch by 72 ppi images for screen display. I'm
keeping them in an electronic catalog of my images. Unless something has
changed in Photo Shop 7, which I recently acquired, sharpening is much more
Tomek Zakrzewski [EMAIL PROTECTED] asked:
What color spaces is best to choose for the following purposes:
- printed material, for example a magazine or a photographic book
- stock photography (image bank)
- inkjet
and Maris V. Lidaka Sr. [EMAIL PROTECTED] suggested:
I also would suggest Adobe
Good point - you are correct.
Maris
- Original Message -
From: Anthony Atkielski [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Sunday, June 09, 2002 3:33 AM
Subject: [filmscanners] Re: JPG sharpening [was: Color spaces for different
purposes]
Maris writes:
True enough, but if the
I use an onboard video card (8MB?) in an 800MHz Pentium 3, 512MB RAM PC. I
can't compare speeds to a 32MB video card but the speed of my editing is
fine. Maybe I don't appreciate the speed of a 32MB video card but I can't
imagine a huge difference when I manipulating 27MB (8 bit) or 55MB (16 bit)
I ran this question by last week and received one reply that wasn't the
solution.
Some of my recent scans done on an SS4000 are showing an odd spike in the
histograms. I first noticed this when I was doing Levels correction in
Photoshop. I checked the histograms in both Polacolor Insight and
On Sun, 9 Jun 2002 10:52:22 -0230, you wrote:
There seems to be a widespread misconception here. While
you are editing an image, it _does not have_ a format;
it isn't JPEG, or TIFF, or anything else.
The image is stored on a file in JPEG or TIFF or whatever
format you choose, but it has
-Original Message-
So, aside of asking for any observation regarding improving my
workflow - why is the sharpening so much more effective on the smaller
image?
In PS there are three parameters for USM. One of them is the radius. The
bigger the radius the more surounding pixels are
So the moral of the story is you have to know your printing company and act
accordingly. Perhaps save in Adobe RGB for now, and when you find a printer
talk to them - you can then convert to Colormatch RGB if they are not
color-management aware or if that's what they prefer.
Maris
-
Initial sharpening is what Bruce Frasier recommends:
http://www.creativepro.com/story/feature/12189.html
As to the effectiveness of sharpening on the smaller image - you have fewer
pixels to work with, so the same sharpening radius will be much more
visible.
Maris
- Original Message -
Plain and simple, do you agree that a dynamic range of 5000:1 REQUIRES
13
bits to represent every integer value between 1 and 5000? If so, then
where's the problem? If not, then plain and simple, why not?
Austin
I think where we differ is the assumption the a 5000:1 dynamic range
Sharpness cannot be restored, it can only be simulated. Sharpening causes
deterioration in image quality, so it should be avoided until the image is
about to be prepared for a specific use. I archive all my images without
sharpening.
Agree. This is how I do mine. I'll do all the crop, tonal
Another aspect of purposing, different for different destinations, is the
file format. I've had more than one publicist and publisher request that I
provide (email, ftp) a jpeg in preference to a tiff because of the file
size. (For this I use a
high/maximum quality in photoshop terms: 10 to
Peter,
It must be the nature of the discussion or the topic; but just when I think
I am beginning to get a handle on it something muddies the water. :-)
The first point of confusion in your discussion with Austin appears to be
that what you are referring to as dynamic range he is referring to
Really good answer Robert.
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Robert Meier
Sent: Sunday, June 09, 2002 11:27 AM
To: [EMAIL PROTECTED]
Subject: [filmscanners] RE: JPG sharpening [was: Color spaces for
different purposes]
-Original
I have to wonder if the publicist and publisher are requesting jpeg
files rather than lwz compressed TIFF files out of force of habit ...
From one, file size was specifically mentioned. Others may be due to habit, or their
experience that once image goes through their prepress and screening
Of course, I hope you understand that my question was rhetorical. I hope
that you were just using my rhetorical question as a vehicle for expressing
your remarks rather than taking it seriously as a literal question in need
of an answer.
-Original Message-
From: [EMAIL PROTECTED]
I have not noticed this with my SS4000. Can you scan the same slides on
another scanner (not necessarily another SS4000 although that would be good)
to see if it's an anomaly with your scanner?
Tom
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of S
However, if you save an image as JPEG using the lowest (least) possible
compression, the saved version will be essentially identical to the
original
scan.
I agree with this; but in many if not most cases, the compression level used
or required is greater then the lowest possible amount, ranging
At 01:20 PM 6/9/02 -0500, Laurie Solomon wrote:
Although I concur with all you have said, I have to wonder if the publicist
and publisher are requesting jpeg files rather than lwz compressed TIFF
files out of force of habit, lack of knowledgabout the ability to compress
TIFFs using the lwz
All images are bitmaps at the time of sharpening. The format in which they
were or will be stored is irrelevant
I have no problem with that. My reference was to the possibilities of
separating the conversion process from the compression process when saving
to JPG format and not with the state
I have tried the software (Insight) on another machine, with the same
scanner, and SCSI card, and the instability is still there.
Brian Boggenpoel
On Sat, 8 Jun 2002 23:35:01 +0100
Eddie Cairns [EMAIL PROTECTED] Wrote:
This could point to a PC
Date sent: Sun, 09 Jun 2002 08:54:14 -0600
Send reply to: [EMAIL PROTECTED]
From: Don Marcotte [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Subject:[filmscanners] Re: Onboard Graphics and Filmscanning
I use an onboard video
My scanner is the only one I have access to.
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Thomas B. Maugham
Sent: Sunday, June 09, 2002 2:03 PM
To: [EMAIL PROTECTED]
Subject: [filmscanners] RE: SS4000 scans--strange pixel spike in
histogram
I have
For what it's worth, I had terrible instability with Polacolor and Win98.
That problem completely disappeared with a switch to Win2000 Professional.
Stan
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of brian boggenpoel
Sent: Sunday, June 09, 2002 3:23
Date sent: Sun, 09 Jun 2002 15:09:58 -0400
Send reply to: [EMAIL PROTECTED]
From: Johnny Johnson [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Subject:[filmscanners] Re: Archiving and when to sharpen (was:Color
spaces for
At 05:32 PM 6/9/02 -0400, Mac wrote:
Wow, are you sure? The LZW TIFF was *larger*?
That's unusual.
Hi Mac,
Thanks for asking - it looks like the original TIFF file that I grabbed
must have already been saved with lwz compression. So, I did the
experiment again using a fresh scan of a
It's not that unusual, though I don't recall why, and LZW compression will
not reduce file size nearly as much as JPG
Maris
- Original Message -
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Sunday, June 09, 2002 4:32 PM
Subject: [filmscanners] Re: Archiving and when to sharpen
Don, your support of Ken is a bit misplaced. TIFF vs. JPEG is non
sequitur, Anthony is correct. This is about the pixels in the image,
not about the file format in which it's saved.
When an unsharp mask (a.k.a. sharpening) is applied to an image, it is
enhancing the contrast of edges or areas
Laurie Solomon [EMAIL PROTECTED] asked:
Scans do not contain more detail than a low-compression JPEG can
hold.
This statement I do not understand; please elaborate. Surely, this cannot
be the case if we are talking about raw data as opposed to encoded
compressed data even at the lowest
Laurie writes:
I agree with this; but in many if not most
cases, the compression level used or required
is greater then the lowest possible amount,
ranging from level 6 to level 3 in order to
get the file small enough to be an email attachment
or a web site download.
I was thinking only
Laurie writes:
In practice, I do not think they are seperable
so as to allow some other action to be carried
out between the two processes, although it may be
theoretically possible.
JPEG encoding requires the rough equivalent of a Fourier transformation on
the data; once that is
yes; if there are many pixels of same color, image
will compress more.
And that is almost never true for real-world photographs, although it is
certainly true quite often for computer-generated images such as diagrams
and the like.
Wow, are you sure? The LZW TIFF was *larger*?
It can be if
Hi Laurie,
The first point of confusion in your discussion with Austin appears to be
that what you are referring to as dynamic range he is referring to as
density range or that you are using the two terms synonomously
while he is
using them as naming two different concepts.
Dynamic range
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Plain and simple, do you agree that a dynamic range of 5000:1 REQUIRES
13
bits to represent every integer value between 1 and 5000? If so, then
where's the problem? If not, then plain and simple, why not?
Austin
Hi Peter,
Sorry if I sounded a bit surely in my last response.
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This is why you should never apply the unsharp masking on your high-res
scans until the final target use of the image is known, and, if
necessary, the image is resampled down for that use. For example, if
you print a 360dpi image on a high quality inkjet printer on glossy
media, you would
Dynamic range is, in our case, (dMax - dMin) / noise.
I guess I tend to want to stay away from that definition in part because I
am not really able to visualize it very well; but I can visualize Dynamic
range is the number of discernable values within a density range (in our
case) much better so
I was thinking only of archived photos. For Web and e-mail use, in most
cases you can crank the compression all the way up in Photoshop (that is,
set it down to 1, the highest compression setting) and the image will still
look fine. Unlike some editing programs, Photoshop won't let you
We may have taken separate paths to get there; but I believe that we both
reached the same conclusion for either different reasons or by using
different means of expression. :-)
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Anthony Atkielski
Sent:
Date sent: Sun, 9 Jun 2002 19:42:32 -0500
Send reply to: [EMAIL PROTECTED]
From: Maris V. Lidaka Sr. [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Subject:[filmscanners] Re: Archiving and when to sharpen (was:Color
spaces for
David,
I am not an engineer so I could very well be using terms that have
techincally precise meanings in imprecise commonsense everyday fashions. By
raw data, I only meant to designate the original data captured by the scan
prior to any compression; and thus, I was only trying to say that if
Is it not lzw compression instead of lwz?
Yes, my fingers went faster than my mind when I wrote it. :-(
Your comment that lzw compressed TIFF files are as small as JPGs made me
wonder if you are working with graphic files and if they offer better
compression than photos.
I must be candid and
Date sent: Sun, 09 Jun 2002 18:59:45 -0400
Send reply to: [EMAIL PROTECTED]
From: Johnny Johnson [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Subject:[filmscanners] Re: Archiving and when to sharpen(was:Color
spaces for
Your clarification has helped; and I have no significant disagreement with
the gist of your statements now that I understand what you are saying and
what you are using as your reference criteria.
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Anthony
At 08:42 PM 6/9/2002, wrote:
If this same image was used for web, you would first downsample it to
72dpi, then unsharp mask it for appropriate level of crispness at that
resolution.
While I agree with what you say, the reason for it is wrong. 72dpi has
no meaning for
screen viewing. Only
I have occasionally gotten JPEGs that were larger than the original,
uncompressed TIFF file if the file contained a lot of detail and had been
heavily sharpened, and the JPEG compression was set at maximum quality /
minimum compression. So it can happen, but in my personal experience only
rarely.
I think you should reread what Ken and I are saying - the effect of
sharpening is more visible in a low res image, no more no less. Your
lengthy explanation below is helpful in explaining why it is more visible.
Thank you for that. The original response sailed by his question and I was
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