I posted questions about this problem with Vuescan before, and I
thought I had it solved, but I'm bumping into it again and wish I
could get some help in understanding what's going on. In particular,
I wish Ed could help identify what the color processing is doing to
produce this problem and how I could correct it. I haven't upgraded
to V8.0 yet - I only just learned about it when I went to post this
message.

The problem I am having is obtaining good scans when blue sky is a
significant part of the image. This time, I started by reseting the
Vuescan default options and changing only the scan mode and media type
for color negatives. The problem I'm experiencing is illustrated and
explained here:

http://www.intergate.com/~wcb/color/color.htm

The images look fine when the preview focuses on a normal landscape
scene, but becomes horrible when focusing on a blue sky picture. Does
anyone have any idea how to solve this problem?

Thanks -- Bill (w c b # trip - net)

"Billman" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I posted questions about this problem with Vuescan before, and I
> thought I had it solved, but I'm bumping into it again and wish I
> could get some help in understanding what's going on. In particular,
> I wish Ed could help identify what the color processing is doing to
> produce this problem and how I could correct it. I haven't upgraded
> to V8.0 yet - I only just learned about it when I went to post this
> message.
>
> The problem I am having is obtaining good scans when blue sky is a
> significant part of the image. This time, I started by reseting the
> Vuescan default options and changing only the scan mode and media type
> for color negatives. The problem I'm experiencing is illustrated and
> explained here:
>
> http://www.intergate.com/~wcb/color/color.htm
>
> The images look fine when the preview focuses on a normal landscape
> scene, but becomes horrible when focusing on a blue sky picture. Does
> anyone have any idea how to solve this problem?

Have you tried cropping a bit tighter (no edges included)? You can also try
an scan another image, shot under the same lighting conditions. If that
looks good, lock its image color and then scan this image.

Bart

Bill:

I'm not familiar with VS, but it appears that the mode you're using for the
images that fail tries to force a black-white point in the image. It's
obvious that the building images, for example, don't have a black and a
white.

Dane

> The images look fine when the preview focuses on a normal landscape
> scene, but becomes horrible when focusing on a blue sky picture. Does
> anyone have any idea how to solve this problem?

"Billman" <(E-Mail Removed)> wrote:
> The problem I am having is obtaining good scans when blue sky is a
> significant part of the image. This time, I started by reseting the
> Vuescan default options and changing only the scan mode and media type
> for color negatives. The problem I'm experiencing is illustrated and
> explained here:
>
> http://www.intergate.com/~wcb/color/color.htm

Try using the "Advanced Workflow Suggestions" in the VueScan
User's Guide.

You might also try clicking with the right mouse button (or holding
down the control key on Mac OS) to choose the neutral color.

Regards,
Ed Hamrick

Any reason why you are not happy with the Twain Driver and EPSON Scan
Utility v1.25A?
I have an Epson 3200 and we share the same Epson software. I also
have Vuescan. Most of the time I'm very pleased with the results from
Epson. It's faster and the quality is on par with Vuescan. Vuescan
does have a few other features like the ability to scan once but save
to multiple formats. I like Vuescan and it's my backup option when I
just can't get it right with Epson Scan Utility.

"eastern" <(E-Mail Removed)> wrote in message news:<Gudrc.36299$(E-Mail Removed)>...
> Bill:
>
> I'm not familiar with VS, but it appears that the mode you're using for the
> images that fail tries to force a black-white point in the image. It's
> obvious that the building images, for example, don't have a black and a
> white.
>
> Dane
>
> > The images look fine when the preview focuses on a normal landscape
> > scene, but becomes horrible when focusing on a blue sky picture. Does
> > anyone have any idea how to solve this problem?

eastern wrote:
>
> Bill:
>
> I'm not familiar with VS, but it appears that the mode you're using for the
> images that fail tries to force a black-white point in the image. It's
> obvious that the building images, for example, don't have a black and a
> white.

The lower strip looks indeed like a typical case with Black Point > 0.
Vuescan reacts very radically to such cases where there is nothing
even close to black (lack of sanity check measure...)

What strikes me in these examples is though a lack of essential
information about setting: What is media type: slide, image. negative??
What is the selected color balance? What are White and Black point?
Please provide these details and I am sure that we can help.

For example regarding blue sky, Vuescan cannot deal well with images
containing almost only blue sky in conjunction with the White Balance.
Blue can be turned in a kind of lead-gray, literally. There again,
its a lack of sanity check in the algorithm. We spoke a while ago
that the one interesting notion of color adjustment is dealing with
what we consider memory colors (see Fraser's "Color Management").
Memory colors are colors which we consider real or not, based on
our subjective perception: skin tones, grass green, sky etc. etc.

Tools like Paint Shop Pro have even special buttons to inform
algorithms of a presence of skin tones etc. to prevent their
transformation into tones which we would perceive false.

Thomas

>
> Dane
>
> > The images look fine when the preview focuses on a normal landscape
> > scene, but becomes horrible when focusing on a blue sky picture. Does
> > anyone have any idea how to solve this problem?

> Have you tried cropping a bit tighter (no edges included)? You can also try
> an scan another image, shot under the same lighting conditions. If that
> looks good, lock its image color and then scan this image.

I haven't tried that yet, Bart, but I'm willing to try anything.

Thanks - Bill

> I'm not familiar with VS, but it appears that the mode you're using for the
> images that fail tries to force a black-white point in the image. It's
> obvious that the building images, for example, don't have a black and a
> white.
>
> Dane

Thanks, Dane -- another responder mentioned the black-point setting -
I'll give this a try, too.

Bill

(E-Mail Removed) (David R) wrote in message news:<(E-Mail Removed)>...
> Any reason why you are not happy with the Twain Driver and EPSON Scan
> Utility v1.25A?
> I have an Epson 3200 and we share the same Epson software. I also
> have Vuescan. Most of the time I'm very pleased with the results from
> Epson. It's faster and the quality is on par with Vuescan. Vuescan
> does have a few other features like the ability to scan once but save
> to multiple formats. I like Vuescan and it's my backup option when I
> just can't get it right with Epson Scan Utility.

Hi, Dave --

My Epson TWAIN driver actually works great on images such as those I'm
having trouble with. I'm seeking help on my Vuescan issue because I
like the flexibility of VS, the generally great response I get from
it, and I like to get a routine workflow going when processing my
images (i.e., no flipping back and forth between scanning programs).

But perhaps I should just cut my losses timewise and go back to the
Epson drivers for these problem images.

Bill

Thanks, Thomas --

All of my settings were those that Vuescan resets to with when
selecting the "Default Options" from the File menu. The only settings
I changed were "Transparency" and "Color Negative" - everything else
was "default". Which means that the color mode was "white balance", so
perhaps that is a source/contributor to the problem. I've experience
this:

> Blue can be turned in a kind of lead-gray, literally.

quite frequently with Vuescan+Blue Sky (much to my chagrin).

I'll experiment some more with black point/white point and see what
happens.

Thanks,

Bill





ThomasH <(E-Mail Removed)> wrote in message news:<(E-Mail Removed)>...
> eastern wrote:
> >
> > Bill:
> >
> > I'm not familiar with VS, but it appears that the mode you're using for the
> > images that fail tries to force a black-white point in the image. It's
> > obvious that the building images, for example, don't have a black and a
> > white.
>
> The lower strip looks indeed like a typical case with Black Point > 0.
> Vuescan reacts very radically to such cases where there is nothing
> even close to black (lack of sanity check measure...)
>
> What strikes me in these examples is though a lack of essential
> information about setting: What is media type: slide, image. negative??
> What is the selected color balance? What are White and Black point?
> Please provide these details and I am sure that we can help.
>
> For example regarding blue sky, Vuescan cannot deal well with images
> containing almost only blue sky in conjunction with the White Balance.
> Blue can be turned in a kind of lead-gray, literally. There again,
> its a lack of sanity check in the algorithm. We spoke a while ago
> that the one interesting notion of color adjustment is dealing with
> what we consider memory colors (see Fraser's "Color Management").
> Memory colors are colors which we consider real or not, based on
> our subjective perception: skin tones, grass green, sky etc. etc.
>
> Tools like Paint Shop Pro have even special buttons to inform
> algorithms of a presence of skin tones etc. to prevent their
> transformation into tones which we would perceive false.
>
> Thomas
>
> >
> > Dane
> >
> > > The images look fine when the preview focuses on a normal landscape
> > > scene, but becomes horrible when focusing on a blue sky picture. Does
> > > anyone have any idea how to solve this problem?