Acdsee shows whitespace as gray

[Franklin]

I scanned some text documents and created JPG files.

(a) If I open the jpegs in Irfanview and print then the documents
come out normally as black text on a white background.

(b) If I open the same jpegs in my old ACDSee 3.1 then the documents
come out as black print on a *LIGHT GRAY* background.

In the past ACDSee 3.1 was fine to print jpegs of a text document.
What is happening? The main system changes have been installing XP
SP2 and reinstalling ACDsee 3.1


SOME MORE DETAILS

There are not many settings for ACDSee 3.1 and almost none have
anything to do with picture quality. The scans were done by
launching ACDSee and then calling TWAIN from there.

GIFs print as black on white. JPEGS are visibly black on GRAY.

 

[tacit]

I scanned some text documents and created JPG files.

Issues with ACDSee aside, is there a reason you chose to save the files
as JPEG instead of some other format? You may have made a mistake by
saving them as JPEG.

JPEG is a "lossy" format. That means the quality of any scan you save as
a JPEG is degraded in order to make the file smaller on disk. JPEG is
especially bad on text, making it (or anything else with hard, straight
lines) "blurry."

JPEG was invented for situations where file size is very important and
image quality is not important. You should never save any scan as a JPEG
unless there is some clear, specific reason why it *has* to be JPEG and
no other format will work.

 

[Greg N.]

JPEG is a "lossy" format. That means the quality of any scan you save as
a JPEG is degraded in order to make the file smaller on disk. JPEG is
especially bad on text, making it (or anything else with hard, straight
lines) "blurry."

It's all a function of the compression level you choose. If you use
mild compression, your text will be just fine, while the resulting JPG
is still only a fraction of the size of the corresponding TIFF.

JPEG was invented for situations where file size is very important and
image quality is not important.

If you're dealing with a collection of a few thousand scanned text
documents, size may matter a lot.

You should never save any scan as a JPEG
unless there is some clear, specific reason why it *has* to be JPEG and
no other format will work.

More often than not, scanning is for document archival, where image
quality is not really important. For text documents, my take is, as
long as it's well readable and printable, it's OK to store it as JPG.

 

[Scruff]

Why twain them through Acdsee when you can do an infinitely better job
through
PhotoShop.
And if you don't have photoshop, why are you posting here?

 

[tacit]

More often than not, scanning is for document archival, where image
quality is not really important. For text documents, my take is, as
long as it's well readable and printable, it's OK to store it as JPG.

Actually, if you want the highest possible quality AND small files, the
best approach is to scan text as a one-bit bitmap, rather than as
grayscale, then save the bitmap as a TIFF.

If the original source is bilevel--no shades of gray--then it will print
better if it is scanned as a high-resolution bitmap. What's more, the
file will be smaller than a JPEG grayscale file, and it will print more
cleanly. If it's saved as an LZW-compressed TIFF, the file size will be
very small indeed, yet it will have absolutely none of the degradation
of JPEG.

Scan color originals in color. Scan grayscale originals in grayscale.
Scan black and white originals as bitmap.

 

[Greg N.]

Actually, if you want the highest possible quality AND small files, the
best approach is to scan text as a one-bit bitmap, rather than as
grayscale, then save the bitmap as a TIFF.

1-bit images are a remnant of the past, from the times 20 years ago when
efficient jpeg compression was not the the de-facto norm yet.

If the original source is bilevel--no shades of gray--then it will print
better if it is scanned as a high-resolution bitmap. What's more, the
file will be smaller than a JPEG grayscale file, and it will print more
cleanly. If it's saved as an LZW-compressed TIFF, the file size will be
very small indeed, yet it will have absolutely none of the degradation
of JPEG.

These days, not many people find bi-level images very useful any more,
because because the notion of "bilevel - no shades of gray" does not
really exist in practice. You'll have no anti-aliasing effect without
an appropriate range of grey levels. Characters will become jagged.
Images of text may become hard to read or plain unusable if the type
is small or if character edges are not well defined.

The only way around this would be to use very high resolution, which
defeats the purpose of bi-evel representation, namely image file
compactness. My take is, forget about bi-level representation, it
stinks for most practical applications.

Scan color originals in color. Scan grayscale originals in grayscale.
Scan black and white originals as bitmap.

Bitmap versus color or grayscale? What do you mean by that? Bitmap is
a file format that can represent any color depth you chose, from
bi-level to RGB.

 

[tacit]

These days, not many people find bi-level images very useful any more,
because because the notion of "bilevel - no shades of gray" does not
really exist in practice. You'll have no anti-aliasing effect without
an appropriate range of grey levels. Characters will become jagged.
Images of text may become hard to read or plain unusable if the type
is small or if character edges are not well defined.

With low-res images, sure.

But you're making a big, big mistake if you believe that 1-bit bitmaps
are a thing of the past. All laser printers print 1-bit bitmaps. All
imagesetters print 1-bit bitmaps. They are incapable of printing shades
of gray.

Ironically, 1-bit images print far better to a laser printer or an
imagesetter than grayscale images do, because such devices produce
shades of gray by halftoning--printing patterns of dots to simulate
levels of gray--and a 1-bit image prints with no halftoning, whereas a
grayscale image prints with little halftone dots all around the edges of
the characters.

A bitmap looks jaggy on a computer screen, but prints far better than a
grayscale image for this reason.

It seems to me that you are likely inexperienced with prepress and with
digital output, else you would not be saying things like "1-bit images
are a remnant of the past."

 

[Nils]

And if you don't have photoshop, why are you posting here?

Huh? This is comp.compression. I don't have photoshop and I like reading and
posting here. Why would I need to have photoshop when posting here? Does
owning photoshop make me magically more educated on compression techniques?

Nils

 

[Willem]

Nils wrote:
)> And if you don't have photoshop, why are you posting here?
)
) Huh? This is comp.compression. I don't have photoshop and I like reading and
) posting here. Why would I need to have photoshop when posting here? Does
) owning photoshop make me magically more educated on compression techniques?

Welcome to the wonderful world of crossposting.

quote from the header:

) Newsgroups: comp.periphs.scanners,alt.graphics.photoshop,comp.compression


SaSW, Willem
--
Disclaimer: I am in no way responsible for any of the statements
made in the above text. For all I know I might be
drugged or something..
No I'm not paranoid. You all think I'm paranoid, don't you !
#EOT

 

[Franklin]

On Sun 13 Nov 2005 16:31:23, Scruff wrote:

Why twain them through Acdsee when you can do an infinitely
better job through PhotoShop.
And if you don't have photoshop, why are you posting here?

Yes I run Photoshop 8 as well as ACDSee 3.

But isn't it the same Twain driver which gets called (the Epson
5.71) irrespective of which application calls it? In Photoshop if
I go to File > Import then I am given a choice of drivers
including Epson Twain.

How would Photshop do an infinitely better job for me?

 

[Scruff]

Huh? This is comp.compression. I don't have photoshop and I like reading and
posting here. Why would I need to have photoshop when posting here?

Because you're crossposting, you utter moron.

Does owning photoshop make me magically more educated on compression

techniques?
Yes, If you were using Photoshop, it would prove that you at least had half
a clue, which you don't.

 

[Scruff]

On Sun 13 Nov 2005 16:31:23, Scruff wrote:



Yes I run Photoshop 8 as well as ACDSee 3.

But isn't it the same Twain driver which gets called (the Epson
5.71) irrespective of which application calls it? In Photoshop if
I go to File > Import then I am given a choice of drivers
including Epson Twain.

How would Photshop do an infinitely better job for me?

Because it is an infinitely better program for what you are doing.
Acdsee 3.1 is obsolete.

 

[Greg N.]

But you're making a big, big mistake if you believe that 1-bit bitmaps
are a thing of the past. All laser printers print 1-bit bitmaps.

Whoa, that's a terminology stretch as well as a topic mixup.

We're talking about the appropriate image _storage_ format which has
nothing to do with the representation of that image in the print queue
of a laser printer.

Sure, the printer does black dots only, but you should not conclude from
this that bi-level is an effective modern storage format or even that it
is frequently used in other than legacy applications.

I suggest a a little math:

In order to store a letter size page in bi-level format we'd need to use
at _least_ the same resolution as the printer, othewise we'd get shitty
prints. At 600 dpi, we'd need a 5100x6600 image, which is some 33
megabits raw.

With LZW compression applied, a page that contains type only may result
in a 200k image file, while a page with some imagery may easily result
in a 500k image file.

The same thing stored as jpeg would need hardly more than 25% of that
resolution (1275x1650). Moderately compressed, it would end up as a 100k
JPG file, still print the same and look infinitely better on screen.

You may be experienced more with typesetting than with mass document
archival. These days, nobody would design a _new_ document image
archival system using bi-level images.

 

[Sachin Garg]

I scanned some text documents and created JPG files.

(a) If I open the jpegs in Irfanview and print then the documents
come out normally as black text on a white background.

(b) If I open the same jpegs in my old ACDSee 3.1 then the documents
come out as black print on a *LIGHT GRAY* background.

In the past ACDSee 3.1 was fine to print jpegs of a text document.
What is happening? The main system changes have been installing XP
SP2 and reinstalling ACDsee 3.1


SOME MORE DETAILS

There are not many settings for ACDSee 3.1 and almost none have
anything to do with picture quality. The scans were done by
launching ACDSee and then calling TWAIN from there.

GIFs print as black on white. JPEGS are visibly black on GRAY.

As far a as I can think, its probably because of incorrect ICC profiles
being used, or profiles being applied incorrectly.

ICC profiles try match the capture-device and display-device
characteristics to ensure that you see the same shades on each type of
device

(eg to make sure white has same whiteness on all mointors, and black
has same blackness on all printers/papers)

Sachin Garg [India]
http://www.sachingarg.com

 

[Sachin Garg]

With low-res images, sure.

But you're making a big, big mistake if you believe that 1-bit bitmaps
are a thing of the past. All laser printers print 1-bit bitmaps. All
imagesetters print 1-bit bitmaps. They are incapable of printing shades
of gray.

Ironically, 1-bit images print far better to a laser printer or an
imagesetter than grayscale images do, because such devices produce
shades of gray by halftoning--printing patterns of dots to simulate
levels of gray--and a 1-bit image prints with no halftoning,

I think the correct word here is "dithering", not halftoning.

whereas a
grayscale image prints with little halftone dots all around the edges of
the characters.

A bitmap looks jaggy on a computer screen, but prints far better than a
grayscale image for this reason.

This probably explains why some PDFs are too jaggy to be read on screen
but come out just fine on paper. Thanks for the info.


Sachin Garg [India]
http://www.sachingarg.com

 

[Willem]

)> A bitmap looks jaggy on a computer screen, but prints far better than a
)> grayscale image for this reason.

Sachin wrote:

) This probably explains why some PDFs are too jaggy to be read on screen
) but come out just fine on paper. Thanks for the info.

Get yourself a decent PDF viewer; one that antialiases well.


SaSW, Willem
--
Disclaimer: I am in no way responsible for any of the statements
made in the above text. For all I know I might be
drugged or something..
No I'm not paranoid. You all think I'm paranoid, don't you !
#EOT

 

[tacit]

In order to store a letter size page in bi-level format we'd need to use
at _least_ the same resolution as the printer, othewise we'd get shitty
prints. At 600 dpi, we'd need a 5100x6600 image, which is some 33
megabits raw.

With LZW compression applied, a page that contains type only may result
in a 200k image file, while a page with some imagery may easily result
in a 500k image file.

The same thing stored as jpeg would need hardly more than 25% of that
resolution (1275x1650). Moderately compressed, it would end up as a 100k
JPG file, still print the same and look infinitely better on screen.

Actually, it would not "print the same." The JPEG in your example would
be lower resolution and would not print as cleanly.

Given that a high-resolution, flawless, undegraded representation of a
page can be stored in 500K of space, I hardly think you're making a
compelling argument here. What do you do, archive your data on 800K
floppies?

 

[Nils]

Because you're crossposting, you utter moron.

Seems there's only one moron here, and it's not me.. who started the
crossposting to
begin with?

 

[Greg N.]

Actually, it would not "print the same." The JPEG in your example would
be lower resolution and would not print as cleanly.

Given that a high-resolution, flawless, undegraded representation of a
page can be stored in 500K of space, I hardly think you're making a
compelling argument here. What do you do, archive your data on 800K
floppies?

I think we're starting to argue in circles.

A scan that has lost all grey hues is not "flawless, undegraded".

OK, you don't care about file size? Well, in this case I happily take
the 500k for a letter size scan in greylevel or even RBG, and I'll give
you a jpg that is crisper, sharper, better defined than any old bi-level
scan you've ever seen in your life