High resolution...through digital interpolation...

[Des]

Archived from groups: rec.photo.digital (More info?)

My camera takes photos in normal resolution but claims to be able to take
finer photos at a higher pixel-rate through "digital interpolation".
Surely that's just stretching the image and not worth doing?
Can't I improve the image to the same degree later using filters in Corel
Photopaint?

Is there any real advantage in terms of image quality between an image
that's been digitally interpolated to a higher resolution?
It's no substitute for a higher resolution CCD in the camera is it?

D.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Des wrote:
> My camera takes photos in normal resolution but claims to be able to take
> finer photos at a higher pixel-rate through "digital interpolation".
> Surely that's just stretching the image and not worth doing?
> Can't I improve the image to the same degree later using filters in Corel
> Photopaint?
>
> Is there any real advantage in terms of image quality between an image
> that's been digitally interpolated to a higher resolution?
> It's no substitute for a higher resolution CCD in the camera is it?
>
> D.

You have asked what you might call a loaded question, if you haven't
noticed that already. From a technical point of view resolution is the
smallest object that your camera can detect. This is determined by the
number of pixels in the CCD of your camera (and the camera's optics).
Interpolation CANNOT improve resolution. The only way to improve
resolution is to have a CCD with more pixels. Some people will refer to
resolution in respects to how good a picture looks. Although this isn't
the technical definition of resolution it does get at the desired output
of high resolution (i.e. nicer pictures). This may or maynot be
improved with interpolation, but this kind of "pseudo-resolution" is in
the eyes of the beholder.

What interpolation does is increase the size of the image beyond what
the CCD generates. The process which is used basically stretches out
the image and makes educated guesses as to the color of the new pixels
it creates. Although this creates a larger image, there is no more
detail in the larger image then in the original image. In some cases
interpolation may even decrease the overall results of the image due to
the "guesses" it makes when it expands the image. Not only that, but
interpolated images are larger, so you'll be able to take fewer pictures
if you interpolate.

As for what you should do in terms of taking pictures, my advice would
be to take the pictures at your cameras maximum resolution without
interpolation. This will let you get 100% of your camera's resolution,
without wasting any space on your card. If you want to interpolate or
otherwise alter your images afterwards you can do so with a graphics
program such as Paint Shop Pro or Photoshop. These graphics programs
have multiple other filters you can use, aside form interpolation, so
you'll be able to adjust your images to a greater extent on-computer
then you can on the camera.

Bryan

 

[Larry]

Archived from groups: rec.photo.digital (More info?)

In article <d2ugk2$psk$1@sparta.btinternet.com>,
plinioREMOVEdesignori@btopenworld.com says...
> My camera takes photos in normal resolution but claims to be able to take
> finer photos at a higher pixel-rate through "digital interpolation".
> Surely that's just stretching the image and not worth doing?
> Can't I improve the image to the same degree later using filters in Corel
> Photopaint?
>
> Is there any real advantage in terms of image quality between an image
> that's been digitally interpolated to a higher resolution?
> It's no substitute for a higher resolution CCD in the camera is it?
>
> D.
>
>
>

On some cameras the improvement is there but only slight, on others its just
an up-sizing that gives you a bigger picture, but not a better one.

Fuji makes several that "interpolate upward" and on the S7000 there is
USUALLY some improvement, but the file is twice as big, but NOT 2 times
better. (at any rate, doubling the pixels dosent double the quality anyway,
even if you increase the sensor count, twice as many isnt twice as good, only
twice as big).



--
Larry Lynch
Mystic, Ct.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Des wrote:
> My camera takes photos in normal resolution but claims to be able to take
> finer photos at a higher pixel-rate through "digital interpolation".
> Surely that's just stretching the image and not worth doing?
> Can't I improve the image to the same degree later using filters in Corel
> Photopaint?
>
> Is there any real advantage in terms of image quality between an image
> that's been digitally interpolated to a higher resolution?
> It's no substitute for a higher resolution CCD in the camera is it?
>
> D.
>
>
It is marketing, just like 'digital zoom'. Many 'enhanced digital
zooms' do basically the same thing, interpolating to a larger size, then
cropping.
It's mostly smoke and mirrors, but the pictures usually DO look
smoother, just not more detailed.


--
Ron Hunter rphunter@charter.net

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

On Tue, 05 Apr 2005 17:07:15 +0000, Des wrote:

> My camera takes photos in normal resolution but claims to be able to take
> finer photos at a higher pixel-rate through "digital interpolation".
> Surely that's just stretching the image and not worth doing?
> Can't I improve the image to the same degree later using filters in Corel
> Photopaint?
>
> Is there any real advantage in terms of image quality between an image
> that's been digitally interpolated to a higher resolution?
> It's no substitute for a higher resolution CCD in the camera is it?
>
> D.

There's a simple rule on processing information
(photo/video/audi) digitally:

garbage in = garbage out

It's as simple as that. Any pixel that was not produced by light hitting
the sensor and having its colour properly registered, is not a real pixel.
Sure it may be there, but it doesn't represent any visual information that
was present in the scene when the photo was taken. It was calculated after
the fact and therefore it is artificial.

There is absolutely nothing that a digital process can do after the
picture was taken to add real pixels. It is simply impossible. Now of
course there are plenty of sharpening tricks that create a pretty good
illusion of detail on interpolated images. They're nothing more than
illusions though and you can only go a certain length before the fact that
your pixels are fake starts showing. If the camera gives you all the
pixels it actually captured, then it is in no way capable of more than
good interpolating on your PC.. like Photopaint.

In practice you can usually interpolate up to 125% or even 150% of the
original size, apply a sharpening filter and end up with a decent print.
The result however is no substitute for a higher real resolution.

I see this a lot on really cheap desktop scanners. They claim to go up to
14400dpi while their optics start to struggle beyond 600dpi. Years ago I
bought a $3000,- flatbed scanner that had lesser specs than my neighbor's
$100 scanner, at least when we compared the boxes they came in. Turned out
that 'my' 1000dpi. was a lot sharper than 'his'. All the result of
interpolation and good optics.

Bas

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Des writes:

> My camera takes photos in normal resolution but claims to be able to take
> finer photos at a higher pixel-rate through "digital interpolation".
> Surely that's just stretching the image and not worth doing?

Correct.

> Can't I improve the image to the same degree later using filters in Corel
> Photopaint?

You can't improve an image through any type of manipulation. You will
never have better quality than the image had when originally recorded.
Interpolation is the creation of an optical illusion; it does not
improve real image quality.

> Is there any real advantage in terms of image quality between an image
> that's been digitally interpolated to a higher resolution?

No.

> It's no substitute for a higher resolution CCD in the camera is it?

No, it's not.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Mxsmanic wrote:
> Des writes:
>
>
>>My camera takes photos in normal resolution but claims to be able to take
>>finer photos at a higher pixel-rate through "digital interpolation".
>>Surely that's just stretching the image and not worth doing?
>
>
> Correct.
>
>
>>Can't I improve the image to the same degree later using filters in Corel
>>Photopaint?
>
>
> You can't improve an image through any type of manipulation. You will
> never have better quality than the image had when originally recorded.
> Interpolation is the creation of an optical illusion; it does not
> improve real image quality.
>
>
>>Is there any real advantage in terms of image quality between an image
>>that's been digitally interpolated to a higher resolution?
>
>
> No.
>
>
>>It's no substitute for a higher resolution CCD in the camera is it?
>
>
> No, it's not.
>

Sigh.
Ok, let's start a firestorm here.
IF you have taken a picture at, say 4mp, and the picture has a lot of
sharp lines, some at angles to the horizon, then you CAN get a better
looking picture if you interpolate to a larger size, but ONLY because
the interpolation algorithm is able to insert pictures that are the same
as what would have been captured by a higher resolution sensor. They
aren't 'real', but they end up in the same place as a real one would be,
so the difference is rather more theoretical than practical.

That said, the utility of this kind of interpolation is limited, and
will rarely give you noticeably better results than just processing the
picture with Photoshop.


--
Ron Hunter rphunter@charter.net

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Larry writes:

> On some cameras the improvement is there but only slight, on others its just
> an up-sizing that gives you a bigger picture, but not a better one.

There is never an improvement.

> Fuji makes several that "interpolate upward" and on the S7000 there is
> USUALLY some improvement ...

There is never any improvement. It's a mathematical impossibility.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Mxsmanic wrote:
> Larry writes:
>
>
>>On some cameras the improvement is there but only slight, on others its just
>>an up-sizing that gives you a bigger picture, but not a better one.
>
>
> There is never an improvement.
>
>
>>Fuji makes several that "interpolate upward" and on the S7000 there is
>>USUALLY some improvement ...
>
>
> There is never any improvement. It's a mathematical impossibility.
>
There is an 'apparent' improvement, since 'jaggies' are artificially
reduced.

--
Ron Hunter rphunter@charter.net

 

[Tony]

Archived from groups: rec.photo.digital (More info?)

It is advertising bull. There is no such thing.

--
http://www.chapelhillnoir.com
home of The Camera-ist's Manifesto
The Improved Links Pages are at
http://www.chapelhillnoir.com/links/mlinks00.html
A sample chapter from "Haight-Ashbury" is at
http://www.chapelhillnoir.com/writ/hait/hatitl.html

"Des" <plinioREMOVEdesignori@btopenworld.com> wrote in message
news:d2ugk2$psk$1@sparta.btinternet.com...
> My camera takes photos in normal resolution but claims to be able to take
> finer photos at a higher pixel-rate through "digital interpolation".
> Surely that's just stretching the image and not worth doing?
> Can't I improve the image to the same degree later using filters in Corel
> Photopaint?
>
> Is there any real advantage in terms of image quality between an image
> that's been digitally interpolated to a higher resolution?
> It's no substitute for a higher resolution CCD in the camera is it?
>
> D.
>
>

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

In message <f5n551dc9mak68tph6t1uqmm9ramecprpv@4ax.com>,
Mxsmanic <mxsmanic@hotmail.com> wrote:

>> Fuji makes several that "interpolate upward" and on the S7000 there is
>> USUALLY some improvement ...

>There is never any improvement. It's a mathematical impossibility.

No, you must double the number of pixels in the output to preserve all
the input; that is, if you intend to store in a traditional bitmap
format.

o o o o
o o o
o o o o
o o o

must become

ooooooo
ooooooo
ooooooo
ooooooo

or detail will be lost.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

In message <d2uuq1$894$1@news.ucalgary.ca>,
Bryan Heit <bjheit@nospamucalgary.ca> wrote:

>Interpolation CANNOT improve resolution.

Yes, but the Fuji 7000, when it outputs 6MP from its 6MP sensor *is*
interpolating, with loss. At 12MP, it is also interpolating, but with
*no* loss.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Mxsmanic <mxsmanic@hotmail.com> wrote:

>
> You can't improve an image through any type of manipulation. You will
> never have better quality than the image had when originally recorded.
> Interpolation is the creation of an optical illusion; it does not
> improve real image quality.
>

I suggest that you look into the field of deconvolution algorithms. Images
CAN be improved. NASA/HST do it every day. Not to mention the NRO and a few
other black ops.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Bubbabob wrote:
> Mxsmanic <mxsmanic@hotmail.com> wrote:
>
>
>>You can't improve an image through any type of manipulation. You will
>>never have better quality than the image had when originally recorded.
>>Interpolation is the creation of an optical illusion; it does not
>>improve real image quality.
>>
>
>
> I suggest that you look into the field of deconvolution algorithms. Images
> CAN be improved. NASA/HST do it every day. Not to mention the NRO and a few
> other black ops.

yes, and if you had their processing power in your camera, you could
probably do wonders too. Maybe NEXT year...


--
Ron Hunter rphunter@charter.net

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

>I suggest that you look into the field of deconvolution algorithms. Images
>CAN be improved.

Images can be improved - we all do it when we lighten/darken etc but
that is not interpolation.
Interpolation (as I understand it) turns one pixel into four (for
example) by "Guessing" what the colours should be.
When nasa improve the picture the info is already there and they bring
it to the fore.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

London@am2ma.eu wrote:
>>I suggest that you look into the field of deconvolution algorithms. Images
>>CAN be improved.
>
>
> Images can be improved - we all do it when we lighten/darken etc but
> that is not interpolation.
> Interpolation (as I understand it) turns one pixel into four (for
> example) by "Guessing" what the colours should be.
> When nasa improve the picture the info is already there and they bring
> it to the fore.
>
No, not always. Sometimes they combine information from several frames
of the same data, taken with different filters, or different lighting,
and the software makes educated guesses to fill in the blanks. It isn't
necessarily EXACTLY what a better sensor would record, but it is
PROBABLY what you would see if you were there.



--
Ron Hunter rphunter@charter.net

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

JPS@no.komm wrote in news:sl3651p1vbv6i6clo8fvumcunbd4s56sus@4ax.com:

> In message <d2uuq1$894$1@news.ucalgary.ca>,
> Bryan Heit <bjheit@nospamucalgary.ca> wrote:
>
>>Interpolation CANNOT improve resolution.
>
> Yes, but the Fuji 7000, when it outputs 6MP from its 6MP sensor *is*
> interpolating, with loss. At 12MP, it is also interpolating, but with
> *no* loss.

I'm not sure how you would arrive at that conclusion.

It's much bigger brother the S3, for example, produces very good 6mp
images, but it's 12 mp images aren't on par with those from a true 8MP
body:

http://www.dpreview.com/reviews/fujifilms3pro/page21.asp

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

In message <Xns962FD3AD7A418ericvgillyahoocom@63.223.5.251>,
Eric Gill <ericvgill@yahoo.com> wrote:

>JPS@no.komm wrote in news:sl3651p1vbv6i6clo8fvumcunbd4s56sus@4ax.com:
>
>> In message <d2uuq1$894$1@news.ucalgary.ca>,
>> Bryan Heit <bjheit@nospamucalgary.ca> wrote:
>>
>>>Interpolation CANNOT improve resolution.
>>
>> Yes, but the Fuji 7000, when it outputs 6MP from its 6MP sensor *is*
>> interpolating, with loss. At 12MP, it is also interpolating, but with
>> *no* loss.
>
>I'm not sure how you would arrive at that conclusion.

Define "loss". Hint: it's not "quality of pixel units". It has more to
do with relative absolutes between states.

Using nearest neighbor (for example) to make a 9MP image out of a 1MP
image is not "loss".

>It's much bigger brother the S3, for example, produces very good 6mp
>images, but it's 12 mp images aren't on par with those from a true 8MP
>body:

Probably for most things, but not for resolving horizontal and vertical
edges.


--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Bubbabob writes:

> I suggest that you look into the field of deconvolution algorithms. Images
> CAN be improved.

No, they cannot.

> NASA/HST do it every day. Not to mention the NRO and a few
> other black ops.

No, they don't. It's mathematically impossible, even for the spooks.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Mxsmanic wrote:
> Bubbabob writes:
>
>
>>I suggest that you look into the field of deconvolution algorithms. Images
>>CAN be improved.
>
>
> No, they cannot.
>
>
>>NASA/HST do it every day. Not to mention the NRO and a few
>>other black ops.
>
>
> No, they don't. It's mathematically impossible, even for the spooks.
>
I have explained how it IS possible, and how it IS done. You would
ignore a freight train as it mashed you to a pulp.


--
Ron Hunter rphunter@charter.net

 

[Confused]

Archived from groups: rec.photo.digital (More info?)

On Wed, 06 Apr 2005 06:58:36 +0200
In message <33r6511j3p48qth3penttsq5ctslfn9o0h@4ax.com>
Mxsmanic <mxsmanic@hotmail.com> wrote:

> Bubbabob writes:
>
> > I suggest that you look into the field of deconvolution algorithms.
> > Images CAN be improved.
>
> No, they cannot.
>
> > NASA/HST do it every day. Not to mention the NRO and a few
> > other black ops.
>
> No, they don't. It's mathematically impossible, even for the spooks.

Point of order: He said...

Images CAN be improved.

....which is true.

How much improvement is possible? That is the question.

Jeff

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

In message <33r6511j3p48qth3penttsq5ctslfn9o0h@4ax.com>,
Mxsmanic <mxsmanic@hotmail.com> wrote:

>Bubbabob writes:
>
>> I suggest that you look into the field of deconvolution algorithms. Images
>> CAN be improved.
>
>No, they cannot.
>
>> NASA/HST do it every day. Not to mention the NRO and a few
>> other black ops.
>
>No, they don't. It's mathematically impossible, even for the spooks.

Define "it".

You're talking about increasing maximum sampling resolution; they're
talking about restoring contrast lost to MTF and AA filters.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

London@am2ma.eu writes:

> When nasa improve the picture the info is already there and they bring
> it to the fore.

Yes.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Ron Hunter writes:

> No, not always. Sometimes they combine information from several frames
> of the same data, taken with different filters, or different lighting,
> and the software makes educated guesses to fill in the blanks. It isn't
> necessarily EXACTLY what a better sensor would record, but it is
> PROBABLY what you would see if you were there.

But in this case, also, they are using information obtained from the
original capture. If you can capture more information at the source,
you can improve an image.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Ron Hunter wrote:
> Bubbabob wrote:
>
>> Mxsmanic <mxsmanic@hotmail.com> wrote:
>>
>>
>>> You can't improve an image through any type of manipulation. You will
>>> never have better quality than the image had when originally recorded.
>>> Interpolation is the creation of an optical illusion; it does not
>>> improve real image quality.
>>>
>>
>>
>> I suggest that you look into the field of deconvolution algorithms.
>> Images CAN be improved. NASA/HST do it every day. Not to mention the
>> NRO and a few other black ops.
>
>
> yes, and if you had their processing power in your camera, you could
> probably do wonders too. Maybe NEXT year...
>
>
Also, NASA and HST resolution improvement often hinges on having a good
idea of what an object is, and optimizing algorithms that assume the
shape of an object.

This allows a powerful sharpening. BUT- one needs to be careful. If you
use too much gain in these types of processes, even noise begins to look
like the subject you assumed it was.

An example. Lets say you are trying to improve a picture of a human
face. You can determine what the spectral content (spatial spectrum,
not temperal), and optimize algorithms for that spectral content.
However, if you are not careful, this process can turn almost anything
into something that looks like a human face.