L
Lorenzo J. Lucchini
We've talked a lot about sub-pixel alignment of images for the purpose
of multi-pass multi-sampling.
We've also talked about things like calculating the exact amount of
unsharp masking (or other kinds of sharpening, or possibly even other
transformation) from an MFT (and, perhaps, even from a scanner
photographic image?).
I'll make a summary of the related software tools I've encountered
during this time, as it's not software that seems to be easily found at
first googling.
Hope it can be useful to others, at least as a reference.
ALIGNMENT
* It is possible to do sub-pixel alignment manually in Photoshop (or
another equivalent program), by following a procedure that has been
described more than once by Don and others on comp.periphs.scanners
http://groups.google.com/group/comp.periphs.scanners/msg/de9a8ccc9b9e110d
* HDR Shop allows to create "high dynamic range" images by superimposing
two (or more) pictures taken at different exposures. The program
currently ships as version 2, but version 1 is freely available for
download; however, I haven't managed to perform sub-pixel alignment with it.
(Thanks to Don for pointing to this program)
http://www.debevec.org/HDRShop/
* Optipix is a commercial PhotoShop plug-in (with a downloadable trial
version) that, among some other interesting things, can do sub-pixel
alignment. Like HDR Shop, it's mainly thought out to work with images
taken at different exposures. Optipix also offers a "Refocus" features,
and in fact I'll reference it again in the "deconvolution" section.
(Thanks to Bart van der Wolf for the pointer)
http://www.reindeergraphics.com/optipix/
* Silverfast AI Studio and Silverfast SE Plus recently implemented
multi-pass multi-scanning with automatic sub-pixel alignment. These
products are *not* free.
http://www.silverfast.com/show/silverfast-multisampling/en.html
http://www.silverfast.com
* ALE is an experimental command-line tool for reducing noise and
improving resolution (by reducing aliasing), as well as stitching
"picture mosaics" (although I suppose there are faster tools for that).
Once again, the concept is two take two or more pictures of the same
subject and then aligning and merging them. Compared to other programs,
ALE is able to align pictures that aren't just offset by some fixed x
and y; moreover, it has some advanced algorithms for merging, which go
far beyond just averaging the images together.
The main problem I found with ALE is that it is, well, just slow.
(Thanks to myself for the pointer ;-)
http://auricle.dyndns.org/ALE/
* Sub-pixel alignment is used widely in amateur astrophotography
(usually with a CCD webcam). For this reason, there are a few
astrophotography related tools that offer this feature.
Be advised, however, that the bias towards astrophotography usually
shows: these programs are often hard to learn, and feature sub-pixel
alignment algorithms best suited for nightsky images.)
Registax (free) - http://registax.astronomy.net/
Iris (free) - http://www.astrosurf.org/buil/us/iris/iris.htm
K3CCDTools (free) - http://www.pk3.org/Astro/
MaxIm DL (commercial+demo) - http://www.cyanogen.com/
Astrostack (commercial+demo) - http://www.astrostack.com/
Astroart (commercial+demo) - http://www.msb-astroart.com/
RegiStar (commercial+demo) - http://www.aurigaimaging.com/
... and there are others
DECONVOLUTION
* Image Analyzer is a nice free image editor that offers a few uncommon
features. Among these is a "deconvolution" function, which allows to try
compensating for motion blur, gaussian blur, circular blur and more. It
tries to guess the maths automatically, although I've had little success
with this. It also offers completely automated ("blind") deconvolution,
but again, I've had limited success. It is probably a very good tools if
you know what you're doing, however.
(Thanks to Bart van der Wolf for the pointer)
http://meesoft.logicnet.dk/Analyzer/
* Unshake is a Java and C program (meaning there is graphical version in
Java, and a CLI version in C) to compensate for bad focus and, well,
shaking. It is free for non-commercial use. I was very impressed by the
results of the Java version (didn't try the C version), even though I
could probably achieve a similar-looking result (at least at a
superficial look) on unfocused images with some unsharp masking. Some
thorough tests should probably be made -- for example, I noticed it
produces "phantom" lines surrounding very contrasty edges, for example
in a scan of a page of text.
http://www.hamangia.freeserve.co.uk/
* Refocus-it is an open-source GIMP plug-in (but there is also a
command-line only version included), which gives really impressive
results... according to the screenshots on its web page (which show
unreadably de-focused text being made readable again). I haven't
actually tried it yet, as my Linux machine is only 300MHz and I don't
have a compiler in Windows.
http://refocus-it.sourceforge.net/
* Refocus (without the "it"!) is another open-source GIMP plug-in. This
one doesn't offer a CLI-only version, but it does offer a Windows
executable (still a GIMP plug-in!), which I haven't been able to
execute, possibly because it requires a different version of GTK than I
have.
http://refocus.sourceforge.net/
* As with sub-pixel alignment, many astrophotography related programs
offer some deconvolution features. Please refer to the ones listed in
the "alignment" section, even though not all of them might have
deconvolution. Some that certainly do (not all of these seem to have
alignment, though) are
Iris (free) - http://www.astrosurf.org/buil/us/iris/iris.htm
CCDSharp (commercial?) - http://www.sbig.com/sbwhtmls/ccdsharppr.html
CCDSharp (free?) - http://www.sbig.com/sbwhtmls/softpage.htm
CCDSoft (commercial) - http://www.bisque.com/Products/CCDSoft/
Note that I'm not affiliated, and never have been, with any of the
products I've listed.
Please contribute to this reference list if you can.
by LjL
(e-mail address removed)
of multi-pass multi-sampling.
We've also talked about things like calculating the exact amount of
unsharp masking (or other kinds of sharpening, or possibly even other
transformation) from an MFT (and, perhaps, even from a scanner
photographic image?).
I'll make a summary of the related software tools I've encountered
during this time, as it's not software that seems to be easily found at
first googling.
Hope it can be useful to others, at least as a reference.
ALIGNMENT
* It is possible to do sub-pixel alignment manually in Photoshop (or
another equivalent program), by following a procedure that has been
described more than once by Don and others on comp.periphs.scanners
http://groups.google.com/group/comp.periphs.scanners/msg/de9a8ccc9b9e110d
* HDR Shop allows to create "high dynamic range" images by superimposing
two (or more) pictures taken at different exposures. The program
currently ships as version 2, but version 1 is freely available for
download; however, I haven't managed to perform sub-pixel alignment with it.
(Thanks to Don for pointing to this program)
http://www.debevec.org/HDRShop/
* Optipix is a commercial PhotoShop plug-in (with a downloadable trial
version) that, among some other interesting things, can do sub-pixel
alignment. Like HDR Shop, it's mainly thought out to work with images
taken at different exposures. Optipix also offers a "Refocus" features,
and in fact I'll reference it again in the "deconvolution" section.
(Thanks to Bart van der Wolf for the pointer)
http://www.reindeergraphics.com/optipix/
* Silverfast AI Studio and Silverfast SE Plus recently implemented
multi-pass multi-scanning with automatic sub-pixel alignment. These
products are *not* free.
http://www.silverfast.com/show/silverfast-multisampling/en.html
http://www.silverfast.com
* ALE is an experimental command-line tool for reducing noise and
improving resolution (by reducing aliasing), as well as stitching
"picture mosaics" (although I suppose there are faster tools for that).
Once again, the concept is two take two or more pictures of the same
subject and then aligning and merging them. Compared to other programs,
ALE is able to align pictures that aren't just offset by some fixed x
and y; moreover, it has some advanced algorithms for merging, which go
far beyond just averaging the images together.
The main problem I found with ALE is that it is, well, just slow.
(Thanks to myself for the pointer ;-)
http://auricle.dyndns.org/ALE/
* Sub-pixel alignment is used widely in amateur astrophotography
(usually with a CCD webcam). For this reason, there are a few
astrophotography related tools that offer this feature.
Be advised, however, that the bias towards astrophotography usually
shows: these programs are often hard to learn, and feature sub-pixel
alignment algorithms best suited for nightsky images.)
Registax (free) - http://registax.astronomy.net/
Iris (free) - http://www.astrosurf.org/buil/us/iris/iris.htm
K3CCDTools (free) - http://www.pk3.org/Astro/
MaxIm DL (commercial+demo) - http://www.cyanogen.com/
Astrostack (commercial+demo) - http://www.astrostack.com/
Astroart (commercial+demo) - http://www.msb-astroart.com/
RegiStar (commercial+demo) - http://www.aurigaimaging.com/
... and there are others
DECONVOLUTION
* Image Analyzer is a nice free image editor that offers a few uncommon
features. Among these is a "deconvolution" function, which allows to try
compensating for motion blur, gaussian blur, circular blur and more. It
tries to guess the maths automatically, although I've had little success
with this. It also offers completely automated ("blind") deconvolution,
but again, I've had limited success. It is probably a very good tools if
you know what you're doing, however.
(Thanks to Bart van der Wolf for the pointer)
http://meesoft.logicnet.dk/Analyzer/
* Unshake is a Java and C program (meaning there is graphical version in
Java, and a CLI version in C) to compensate for bad focus and, well,
shaking. It is free for non-commercial use. I was very impressed by the
results of the Java version (didn't try the C version), even though I
could probably achieve a similar-looking result (at least at a
superficial look) on unfocused images with some unsharp masking. Some
thorough tests should probably be made -- for example, I noticed it
produces "phantom" lines surrounding very contrasty edges, for example
in a scan of a page of text.
http://www.hamangia.freeserve.co.uk/
* Refocus-it is an open-source GIMP plug-in (but there is also a
command-line only version included), which gives really impressive
results... according to the screenshots on its web page (which show
unreadably de-focused text being made readable again). I haven't
actually tried it yet, as my Linux machine is only 300MHz and I don't
have a compiler in Windows.
http://refocus-it.sourceforge.net/
* Refocus (without the "it"!) is another open-source GIMP plug-in. This
one doesn't offer a CLI-only version, but it does offer a Windows
executable (still a GIMP plug-in!), which I haven't been able to
execute, possibly because it requires a different version of GTK than I
have.
http://refocus.sourceforge.net/
* As with sub-pixel alignment, many astrophotography related programs
offer some deconvolution features. Please refer to the ones listed in
the "alignment" section, even though not all of them might have
deconvolution. Some that certainly do (not all of these seem to have
alignment, though) are
Iris (free) - http://www.astrosurf.org/buil/us/iris/iris.htm
CCDSharp (commercial?) - http://www.sbig.com/sbwhtmls/ccdsharppr.html
CCDSharp (free?) - http://www.sbig.com/sbwhtmls/softpage.htm
CCDSoft (commercial) - http://www.bisque.com/Products/CCDSoft/
Note that I'm not affiliated, and never have been, with any of the
products I've listed.
Please contribute to this reference list if you can.
by LjL
(e-mail address removed)