Camera correcting lens distortions?

Hi group,

Is there a camera that electronically corrects geometrical lens
distortions (esp. Barrel)? For the fixed-lens digital cameras out
there this should be not hard to implement. It also would
manufacturers allow to use cheaper/lighter glass on their consumer
products and still get decent image quality.

On a similar note, does anybody know a decent lens-distortion
correction software for Linux? It should be able to work on many
images automatically, without manual intervention.

Thanks,

Matthias

On 06 Jul 2004 11:50:08 +0200, Matthias Heiler
wrote:

Is there a camera that electronically corrects geometrical lens
distortions (esp. Barrel)? For the fixed-lens digital cameras out
there this should be not hard to implement. It also would
manufacturers allow to use cheaper/lighter glass on their consumer
products and still get decent image quality.

Matthias,

I don't have an answer to your question. Only wanted to remark
that any recalculation that involves pixel relocation will
necessarily reduce sharpness. I guess that this is one of the
reasons why nobody may be doing it in the camera.

There's most likely some software though.

Hans-Georg

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No mail, please.

Matthias Heiler writes:

Is there a camera that electronically corrects geometrical lens
distortions (esp. Barrel)?

No. It's very difficult because distortions vary with the lens, the
focal length setting (for zooms), the aperture setting, and even the
current focus setting. A camera would have to have all this information
internally recorded for all lenses in order to correct anything.
Additionally, some types of lens defects cannot be corrected after the
fact (such as blurriness).

It also would
manufacturers allow to use cheaper/lighter glass on their consumer
products and still get decent image quality.

They are already using very cheap glass in most cases.

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

I am certain that a software product exists for correcting Barrel distortion
in wide-angle lenses. Sorry I cannot tell you its name! Perhaps Google can
remember better than I can. It may be a Photoshop plug-in. ~Ray
"Matthias Heiler" wrote in message
...
Hi group,

Is there a camera that electronically corrects geometrical lens
distortions (esp. Barrel)? For the fixed-lens digital cameras out
there this should be not hard to implement. It also would
manufacturers allow to use cheaper/lighter glass on their consumer
products and still get decent image quality.

On a similar note, does anybody know a decent lens-distortion
correction software for Linux? It should be able to work on many
images automatically, without manual intervention.

Thanks,

Matthias

In article ,
says...
Hi group,

Is there a camera that electronically corrects geometrical lens
distortions (esp. Barrel)? For the fixed-lens digital cameras out
there this should be not hard to implement. It also would
manufacturers allow to use cheaper/lighter glass on their consumer
products and still get decent image quality.

On a similar note, does anybody know a decent lens-distortion
correction software for Linux? It should be able to work on many
images automatically, without manual intervention.

Thanks,

Matthias

Panorama Tools will correct barrel and pincushion distortion. It is
a plugin for photoshop and is free.
Also lookup ptlens.

--
Robert D Feinman
Landscapes, Cityscapes and Panoramic Photographs
http://robertdfeinman.com
mail:

"Ray Paseur" wrote in message
...
I am certain that a software product exists for correcting Barrel
distortion
in wide-angle lenses. Sorry I cannot tell you its name! Perhaps Google
can
remember better than I can. It may be a Photoshop plug-in. ~Ray

This sort of distortion correction is built into both Paint Shop Pro and
Pano Tools. Of necessity, there is a sharpness reduction. Whether
correction would be better done _before_ the Bayer interpolation or after
is something I would like to know.

It amuses me that so much effort is put into hardware when to do the same
in software is relatively simple coding, and it would not need to be
restricted to fixed-focal length cameras either - a different degree of
correction for each zoom. However, it is a slow process, and the limited
CPU power in digital cameras may be hindering implementation.

Cheers,
David

"David J Taylor" writes:

It amuses me that so much effort is put into hardware when to do the same
in software is relatively simple coding, and it would not need to be
restricted to fixed-focal length cameras either - a different degree of
correction for each zoom. However, it is a slow process, and the limited
CPU power in digital cameras may be hindering implementation.

I'm thinking along the same line. In the best of all worlds cameras
with built-in lens (zoom or prime) would be calibrated by the
manufacturer to correct most distortions automatically. SLRs would
offer a calibration mode where the user takes some images of a
reference object (e.g., a poster provided by the manufacturer) and the
camera measures the distortion of a given lens. Of course, the
correction could be disabled by the user at any time to allow for
maximum sharpness (alternatively one can throw in a couple of extra
megapixels for that).

I understand the CPU argument: Doing the interpolations correctly
would probably require much floating point processing power. But it's
just a matter of time until we have that.

I wonder if any manufacturers are reading this forum... ;-)

"Matthias Heiler" wrote in message
...
[]
I'm thinking along the same line. In the best of all worlds cameras
with built-in lens (zoom or prime) would be calibrated by the
manufacturer to correct most distortions automatically.

... and external lenses could simply provide the required parameters to the
camera's CPU just like they do for other data today. I don't think
there's a need to restrict this to built-in lenses, is there?

SLRs would
offer a calibration mode where the user takes some images of a
reference object (e.g., a poster provided by the manufacturer) and the
camera measures the distortion of a given lens. Of course, the
correction could be disabled by the user at any time to allow for
maximum sharpness (alternatively one can throw in a couple of extra
megapixels for that).

Nice one!

I understand the CPU argument: Doing the interpolations correctly
would probably require much floating point processing power. But it's
just a matter of time until we have that.

... and perhaps sooner than we expect!

I wonder if any manufacturers are reading this forum... ;-)

... I should have patented this idea - although I expect someone already
has.

Cheers,
David

On Tue, 06 Jul 2004 12:59:24 GMT, David J Taylor wrote:
.. and external lenses could simply provide the required parameters to the
camera's CPU just like they do for other data today. I don't think
there's a need to restrict this to built-in lenses, is there?

.. I should have patented this idea - although I expect someone already
has.

Olympus. 4/3 system has provision to do this, don't know if the E-1
currently does though.

--
John Bean

Electricity is actually made up of extremely tiny particles called
electrons, that you cannot see with the naked eye unless you have been
drinking (Dave Barry)

On Tue, 06 Jul 2004 13:14:09 +0200, Mxsmanic
wrote:

No. It's very difficult because distortions vary with the lens, the
focal length setting (for zooms), the aperture setting, and even the
current focus setting. A camera would have to have all this information
internally recorded for all lenses in order to correct anything.
Additionally, some types of lens defects cannot be corrected after the
fact (such as blurriness).

Actually I find the thought fascinating. Who knows, perhaps in a
couple of years we will have cheap cameras with a fixed, cheap
lens and a nonhomogeneous sensor field (higher pixel density in
the center). The camera will take a rather raw image, and all
the fine work, zooming, all kinds of corrections, will be done
by the built-in computer.

One way to increase picture quality could be to take several
photos in quick succession, then process the whole series,
concentrate on the one that is least blurred, take details of
moving objects from other shots in the sequence, etc.

Hans-Georg

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