[gentoo-user] merging or fitting images together

[gentoo-user] merging or fitting images together

[Philip Webb]

I have a lot of images scanned from old negatives of non-standard sizes,
which I had to split up into halves or quarters to process;
I was careful to use the same settings for each of the sub-parts.
Now I want to reassemble them into the original whole pictures.

There are several apps which might do this.
Jonathan Corbet describes using Hugin (LWN 090910);
there's also Krita & Gimp & perhaps Imagemagick.
I have Imagemagick installed, but the others need a number of deps.

Before I go to a lot of trouble emerging + exploring on my own,
has anyone else done this kind of job successfully & what did they use ?

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Alex Schuster]

Philip Webb writes:

> I have a lot of images scanned from old negatives of non-standard sizes,
> which I had to split up into halves or quarters to process;
> I was careful to use the same settings for each of the sub-parts.
> Now I want to reassemble them into the original whole pictures.
> 
> There are several apps which might do this.
> Jonathan Corbet describes using Hugin (LWN 090910);
> there's also Krita & Gimp & perhaps Imagemagick.
> I have Imagemagick installed, but the others need a number of deps.
> 
> Before I go to a lot of trouble emerging + exploring on my own,
> has anyone else done this kind of job successfully & what did they use ?

I'd use ImageMagick's montage command. You have to find out how exactly
to do this, but once you know this, you can automate this and process
them all at once in a loop. If you're not so much into shell scripting,
ask again here.

Sorry, I cannot give you an example right now, but see
http://www.imagemagick.org/Usage/ and expecially
http://www.imagemagick.org/Usage/montage/ , the latter should have the
information.

	Wonko

Re: [gentoo-user] merging or fitting images together

[Dale]

Philip Webb wrote:
> I have a lot of images scanned from old negatives of non-standard sizes,
> which I had to split up into halves or quarters to process;
> I was careful to use the same settings for each of the sub-parts.
> Now I want to reassemble them into the original whole pictures.
> 
> There are several apps which might do this.
> Jonathan Corbet describes using Hugin (LWN 090910);
> there's also Krita & Gimp & perhaps Imagemagick.
> I have Imagemagick installed, but the others need a number of deps.
> 
> Before I go to a lot of trouble emerging + exploring on my own,
> has anyone else done this kind of job successfully & what did they use ?
> 


I have used hugin but it has been a while.  As long as you have enough
points tied together, it works fine.  The more points the better tho.
It has been updated several times since I used it last so it may be
better or worse now.

I have taken as many as 30 pictures and stitched them together.  I had
three rows of 10.  It was of a park and it looked great when done.  It
took a couple tries to get it just right but it did a good job and that
was a good size project.  Doing 4 or 5 pictures is pretty easy.  Lots of
overlap is the key tho.

I don't know of anything else that can do this.  GIMP and such might
could depending on if the image needed some subtle stretching or
something to fit together.

My advice, hugin is likely your best bet.

Dale

:-)  :-)

-- 
I am only responsible for what I said ... Not for what you understood or
how you interpreted my words!

Miss the compile output?  Hint:
EMERGE_DEFAULT_OPTS="--quiet-build=n"

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120510 Dale wrote:
> Philip Webb wrote:
>> I have a lot of images scanned from old negatives of non-standard sizes,
>> which I had to split up into halves or quarters to process;
>> I was careful to use the same settings for each of the sub-parts.
>> Now I want to reassemble them into the original whole pictures.
> I have used hugin but it has been a while.
> As long as you have enough points tied together, it works fine.
> I have taken as many as 30 pictures and stitched them together.
> I had three rows of 10.  It was of a park and it looked great when done.
> It took a couple tries to get it just right but it did a good job
> and that was a good size project.  Doing 4 or 5 pictures is pretty easy.
> Lots of overlap is the key tho.

120510 Alex Shuster wrote :
> I'd use ImageMagick's montage command.
> You have to find out how exactly to do this, but once you know this,
> you can automate this and process them all at once in a loop.
> See http://www.imagemagick.org/Usage/
> and esp http://www.imagemagick.org/Usage/montage/

Thanks to both ! -- Imagemagick looks as if it's very technical
& I'm not sure how it would handle matching overlapping photos.
That is what Corbet described doing & Dale seems to have done,
so I'll emerge Hugin & see what it can do.

As I now notice, the negatives I want to use right now are not split,
but there are many others which are, so this wb useful eventually.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Dale]

Philip Webb wrote:
> 120510 Dale wrote:
>> Philip Webb wrote:
>>> I have a lot of images scanned from old negatives of non-standard sizes,
>>> which I had to split up into halves or quarters to process;
>>> I was careful to use the same settings for each of the sub-parts.
>>> Now I want to reassemble them into the original whole pictures.
>> I have used hugin but it has been a while.
>> As long as you have enough points tied together, it works fine.
>> I have taken as many as 30 pictures and stitched them together.
>> I had three rows of 10.  It was of a park and it looked great when done.
>> It took a couple tries to get it just right but it did a good job
>> and that was a good size project.  Doing 4 or 5 pictures is pretty easy.
>> Lots of overlap is the key tho.
> 
> 120510 Alex Shuster wrote :
>> I'd use ImageMagick's montage command.
>> You have to find out how exactly to do this, but once you know this,
>> you can automate this and process them all at once in a loop.
>> See http://www.imagemagick.org/Usage/
>> and esp http://www.imagemagick.org/Usage/montage/
> 
> Thanks to both ! -- Imagemagick looks as if it's very technical
> & I'm not sure how it would handle matching overlapping photos.
> That is what Corbet described doing & Dale seems to have done,
> so I'll emerge Hugin & see what it can do.
> 
> As I now notice, the negatives I want to use right now are not split,
> but there are many others which are, so this wb useful eventually.
> 


The biggest things about hugin, 1)  learning to use the thing  2)
patience.  The more control points you get, the better it will turn out.
 Whatever you do, don't leave a control point that is not matched up.
Talk about a weird picture.  lol   It only takes one too.

First thing, load your pics.  I usually load them in the sequence they
need to be matched up with.  When you have one image on the left, a
different but connectible image on the right, do one control point
manually.  After the first one, you can pick a point on one image and it
will find it on the other automagically.  If it gives a error, add the
point then delete it.  That's where the weird pictures can come in.
This varies but I try to get at least 10 or 12 points.  That is a
minimum.  If you have the patience and really want a good picture, get
30 points or more.

I would suggest reading a howto with screen shots.  If you need help,
let me know.  It's been a while but I will try.

Oh, hugin can be complicated to.  It has a lot of settings and options.

Dale

:-)  :-)

-- 
I am only responsible for what I said ... Not for what you understood or
how you interpreted my words!

Miss the compile output?  Hint:
EMERGE_DEFAULT_OPTS="--quiet-build=n"

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120511 Dale wrote:
> The biggest things about hugin, 1)  learning to use the thing
> 2) patience.  The more control points you get, the better it will turn out.
> Whatever you do, don't leave a control point that is not matched up.
> Talk about a weird picture.  It only takes one too.

I was careful to make sure there was an overlap in the negatives,
so these are parts of the same image a/a separate shots of the same scene.
That should make matching much more straightforward.
Corbet explained in detail how he made a panorama for separate shots
of a scene in Colorado, where he lives, so that wb my starting-point.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Michael Mol]

On Sat, May 12, 2012 at 9:22 AM, Philip Webb <purslow@ca.inter.net> wrote:
> 120511 Dale wrote:
>> The biggest things about hugin, 1)  learning to use the thing
>> 2) patience.  The more control points you get, the better it will turn out.
>> Whatever you do, don't leave a control point that is not matched up.
>> Talk about a weird picture.  It only takes one too.
>
> I was careful to make sure there was an overlap in the negatives,
> so these are parts of the same image a/a separate shots of the same scene.
> That should make matching much more straightforward.
> Corbet explained in detail how he made a panorama for separate shots
> of a scene in Colorado, where he lives, so that wb my starting-point.

Chiming in late, I know, but I also wanted to recommend Hugin. I've
used it extensively for panoramas.

Also, Hugin has excellent overlap detection algorithms for generating
control points, and its UI for Celeste is good at removing control
points on clouds.

-- 
:wq

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

I tried Hugin, but got nowhere.  I set  6  points on each picture,
which are  2  overlapping parts of a single original negative,
but all it offered was a black screen; I did follow the on-line help.

Then I tried Imagemagick & got a good result after a bit of fussing.
The commands I used were

  convert -size 1000x760 canvas:black brum-canvas.jpg
  composite -geometry +0+0 brum-3070.jpg brum-canvas.jpg brum-1.jpg
  composite -geometry +220-8 brum-3068.jpg brum-1.jpg brum-2.jpg

You can see the images at  http://www.chass.utoronto.ca/~purslow/test/ :
they are of trams in Colmore Row, Birmingham in May 1953 .

I still need to light/darken  1  image a bit to hide the join,
but as a proof of concept this shows it's feasible with Imagemagick.

Any further advice re Hugin is welcome: can anyone do it with these photos ?

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Urs Schutz]

On Mon, 14 May 2012 22:50:33 -0400
Philip Webb <purslow@ca.inter.net> wrote:

> I tried Hugin, but got nowhere.  I set  6  points on each
> picture, which are  2  overlapping parts of a single
> original negative, but all it offered was a black screen;
> I did follow the on-line help.
> 
> Then I tried Imagemagick & got a good result after a bit
> of fussing. The commands I used were
> 
>   convert -size 1000x760 canvas:black brum-canvas.jpg
>   composite -geometry +0+0 brum-3070.jpg brum-canvas.jpg
> brum-1.jpg composite -geometry +220-8 brum-3068.jpg
> brum-1.jpg brum-2.jpg
> 
> You can see the images at
> http://www.chass.utoronto.ca/~purslow/test/ : they are of
> trams in Colmore Row, Birmingham in May 1953 .
> 
> I still need to light/darken  1  image a bit to hide the
> join, but as a proof of concept this shows it's feasible
> with Imagemagick.
> 
> Any further advice re Hugin is welcome: can anyone do it
> with these photos ?
> 

I just tried with fotoxx: This is a semi-manual process, but
I liked the resulting image. The joint is less visible
than on brum-2.jpg. It was easy to do an "unbend" after
merging, and therefore the clock and the face on the image
borders stay in the image. This was my first try to do a
panorama in fotoxx, and it took me less than 5 minutes,
much faster than with hugin. If you like I send you the
image to your private mail.

Urs

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120515 Urs Schutz wrote:
> I just tried with fotoxx.

I hadn't heard of that one : there are so many pkgs in  media/gfx
that it's difficult to be sure I've checked all photo editors.

> This is a semi-manual process, but I liked the resulting image.

It c~b any more manual than Imagemagick (smile).

> The joint is less visible than on brum-2.jpg.

That wb useful : no doubt, I could adjust one of them with Imagemagick,
but eventually there wb  >= 100  similar merges to do,
so some degree of automation wb very helpful.

> It was easy to do an "unbend" after merging
> and therefore the clock and the face on the image borders stay in the image.

Not a problem with Imagemagick.

> This was my first try to do a panorama in fotoxx
> and it took me less than 5 minutes, much faster than with hugin.
> If you like I send you the image to your private mail.

Please do & thanks for this info.

Does anyone else have suggestions re pkgs or methods ?
-- it does look as if this rather simple task is fairly challenging,
so others may benefit if it's on record here.

I have emerged Gimp & will look at what it can do soon :
it has 'layers', which look like what is needed.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120515 Philip Webb wrote:
> 120515 Urs Schutz wrote:
>> I just tried with fotoxx.
>> This is a semi-manual process, but I liked the resulting image.

I've installed Fotoxx & it does a very good job !

>> The joint is less visible than on brum-2.jpg.

There's no sign of it on my version :
  http://www.chass.utoronto.ca/~purslow/test/brum-3.jpg

>> It was easy to do an "unbend" after merging
>> and therefore the clock and the face on the image borders stay in the image.

They're on my image, but I can't find out how to turn it into a rectangle.
NB there are noticeable curves at the R-hand edge not in the original:
look at the sidewalk curve & at the building pediment.
Any suggestions ? -- otherwise, this looks like the tool to use.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Urs Schutz]

On Wed, 16 May 2012 00:12:25 -0400
Philip Webb <purslow@ca.inter.net> wrote:

> 120515 Philip Webb wrote:
> > 120515 Urs Schutz wrote:
> >> I just tried with fotoxx.
> >> This is a semi-manual process, but I liked the
> >> resulting image.
> 
> I've installed Fotoxx & it does a very good job !
> 
> >> The joint is less visible than on brum-2.jpg.
> 
> There's no sign of it on my version :
>   http://www.chass.utoronto.ca/~purslow/test/brum-3.jpg
> 
> >> It was easy to do an "unbend" after merging
> >> and therefore the clock and the face on the image
> >> borders stay in the image.
> 
> They're on my image, but I can't find out how to turn it
> into a rectangle. NB there are noticeable curves at the
> R-hand edge not in the original: look at the sidewalk
> curve & at the building pediment. Any suggestions ? --
> otherwise, this looks like the tool to use.
> 

Transform -> Unbend Image
Play with the vertical values, this is very easy, fast and
intuitive. With brum-3.jpg the best combination was:
vertical linear 5, vertical curved -16, Done
and after that
Transform -> Trim Image or even easier
Transform -> Auto-Trim Image to get rid of the black areas.

In the case of brum-3.jpg apply a little bit of
Retouch -> Gamma Curves, (bend the left part of the curve
a little bit to the bottom, and the right part to the top)
to enhance the image contrast.
Normally the image looses a little bit of sharpness during
the panorama stitching. You can correct this with:
Retouch -> Sharpen Image.

But: If you would like to make an exhibit, then you get
better image quality if you bring the negatives to an old
fashioned photographer for direct enlargement on B&W photo
paper.

Urs

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120516 Urs Schutz wrote:
> On Wed, 16 May 2012 00:12:25 -0400
> Philip Webb <purslow@ca.inter.net> wrote:
>> I can't find out how to turn it into a rectangle.
> Transform -> Unbend Image
> Play with the vertical values, this is very easy, fast and
> intuitive. With brum-3.jpg the best combination was:
> vertical linear 5, vertical curved -16, Done
> and after that
> Transform -> Trim Image or even easier
> Transform -> Auto-Trim Image to get rid of the black areas.
> In the case of brum-3.jpg apply a little bit of
> Retouch -> Gamma Curves, (bend the left part of the curve
> a little bit to the bottom, and the right part to the top)
> to enhance the image contrast.
> Normally the image looses a little bit of sharpness during
> the panorama stitching. You can correct this with:
> Retouch -> Sharpen Image.

Thanks ! -- I tried unbending, but it seemed rather clumsy;
clearly, I need to take more time to get the hang of how it works.

> But: If you would like to make an exhibit, then you get
> better image quality if you bring the negatives to an old-fashioned
> photographer for direct enlargement on B&W photo paper.

I may submit some of them to rail/transit journals for publication,
but won't have a use for hardcopies nor did I know anyone still did that ...

I checked all the apps in media-gfx , but very few are relevant :

  Graphicsmagick -- a long-ago fork of Imagemagick ;
  Digikam -- mb an alternative, but has  39  deps &  155 MB  download ;
  Enblend -- removes dark/light line from .tiff's made eg by Hugin.

Anyway, I have  3  apps to play with & will see where I get to.

Thanks again for your very helpful advice & I HTH others.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Michael Mol]

On Mon, May 14, 2012 at 10:50 PM, Philip Webb <purslow@ca.inter.net> wrote:
> I tried Hugin, but got nowhere.  I set  6  points on each picture,
> which are  2  overlapping parts of a single original negative,
> but all it offered was a black screen; I did follow the on-line help.

Hugin can be tricky, especially if you're using the FastGL mode in an
older version; the FastGL mode didn't really work for me until
recently. The other thing is that you should let its wizard
automatically add the control points for you.

Can you put up the originals somewhere? I'd like to take a shot at
stitching them with Hugin. I've done hundreds of panoramas and HDR
stacks with it.

-- 
:wq

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120516 Michael Mol wrote:
> On Mon, May 14, 2012 at 10:50 PM, Philip Webb <purslow@ca.inter.net> wrote:
>> I tried Hugin, but got nowhere.  I set  6  points on each picture,
>> which are  2  overlapping parts of a single original negative,
>> but all it offered was a black screen; I did follow the on-line help.
> Hugin can be tricky, especially if you're using the FastGL mode
> in an older version; that mode didn't really work for me until recently.

I'm using the latest testing 2011.4.0 ; I didn't try a "fast" mode.

> The other thing is that you should let its wizard
> automatically add the control points for you.

Ah yes : I set the corresponding points in each half myself,
eg the toe of someone's shoe or the top of the further tram's headlamp.

> Can you put up the originals somewhere?

They're at  http://www.chass.utoronto.ca/~purslow/test/ .

> I'd like to take a shot at stitching them with Hugin.
> I've done hundreds of panoramas and HDR stacks with it.

Please do (smile) & send me the result off-list
with the steps you followed to get there.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Stroller]

On 17 May 2012, at 05:34, Philip Webb wrote:
> ...
> Please do (smile) & send me the result off-list
> with the steps you followed to get there.

I have been really enjoying following this thread. 

I felt sure from previous reading on Hugin that it was the correct approach, but when I tried it my results were not very successful and I never got around to improving on them.

I would love it if this could be kept on-list.

Stroller.

Re: [gentoo-user] merging or fitting images together

[Pandu Poluan]

[-- Attachment #1: Type: text/plain, Size: 537 bytes --]

On May 17, 2012 1:07 PM, "Stroller" <stroller@stellar.eclipse.co.uk> wrote:
>
>
> On 17 May 2012, at 05:34, Philip Webb wrote:
> > ...
> > Please do (smile) & send me the result off-list
> > with the steps you followed to get there.
>
> I have been really enjoying following this thread.
>
> I felt sure from previous reading on Hugin that it was the correct
approach, but when I tried it my results were not very successful and I
never got around to improving on them.
>
> I would love it if this could be kept on-list.
>

Same!

Rgds,

[-- Attachment #2: Type: text/html, Size: 740 bytes --]

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120517 Pandu Poluan wrote:
> On May 17, 2012 1:07 PM, "Stroller" <stroller@stellar.eclipse.co.uk> wrote:
>> On 17 May 2012, at 05:34, Philip Webb wrote:
>>> Please do (smile) & send me the result off-list
>>> with the steps you followed to get there.
>> I have been really enjoying following this thread.
>> I felt sure from previous reading on Hugin
>> that it was the correct approach, but when I tried it
>> my results were not very successful & I never got round to improving them.
>> I would love it if this could be kept on-list.
> Same!

Yes, I suspect this is of interest to a number of people.
It's the images themselves which need to be kept off-list:
mine cb found at the I/net site mentioned.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Michael Mol]

On Thu, May 17, 2012 at 12:34 AM, Philip Webb <purslow@ca.inter.net> wrote:
> 120516 Michael Mol wrote:
>> On Mon, May 14, 2012 at 10:50 PM, Philip Webb <purslow@ca.inter.net> wrote:
>>> I tried Hugin, but got nowhere.  I set  6  points on each picture,
>>> which are  2  overlapping parts of a single original negative,
>>> but all it offered was a black screen; I did follow the on-line help.
>> Hugin can be tricky, especially if you're using the FastGL mode
>> in an older version; that mode didn't really work for me until recently.
>
> I'm using the latest testing 2011.4.0 ; I didn't try a "fast" mode.
>
>> The other thing is that you should let its wizard
>> automatically add the control points for you.
>
> Ah yes : I set the corresponding points in each half myself,
> eg the toe of someone's shoe or the top of the further tram's headlamp.
>
>> Can you put up the originals somewhere?
>
> They're at  http://www.chass.utoronto.ca/~purslow/test/ .
>
>> I'd like to take a shot at stitching them with Hugin.
>> I've done hundreds of panoramas and HDR stacks with it.
>
> Please do (smile) & send me the result off-list
> with the steps you followed to get there.

Remarkably simple. Probably because I was only stitching two photos.

1): Emerge hugin. Current stable version is 2011.0.0, and that worked fine.

2) Launch hugin

3) Hugin defaults to leaving the wizard tab open. Load your source
images (brum-3068.jpg, brum-3070.jpg).

Because the files don't have EXIF data provided by the camera, you'll
need to provide some key details about the lens used for the original
pictures. I ventured a guess of 50mm, as that's the same as my prime
lens, it's around the upper end of current kit lenses, and it's around
the lower end of basic macro zoom lenses. It happened to work fine.

4) Click the "Align" button. Hugin will use its wizard to discover
control points and optimize them.

5) Hugin will have popped open the fast preview window. As long as it
looks somewhat fine, go back to the main Hugin window and click on the
Stitcher tab.[1] Enable exposure-corrected, low dynamic range. Keep
everything else disabled. Set your format and quality settings to
taste.

6) Click "Stitch Now". Hugin will put the panorama image in the same
directory as your source images.

I'll email you the stitched-together file off-list.

Outside the emerge, this whole process took less time on an Intel
Pentium B940 than writing this email.

[1] I probably could have clicked the 'Create Panorama' button in the
wizard tab, but I fell back to habits.

-- 
:wq

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120518 Michael Mol wrote:
> Remarkably simple. Probably because I was only stitching two photos.

-- details snipped --

Thanks : that gives me a 3rd method to pursue.

NB in your result there are some badly curved lines :
bottom right, the front of the tram is badly distorted ;
centre top, the sides of buildings are curved outwards ;
also, the bottom of the photo has been lost, eg the L-side man's eyes,
& the result if smaller than the other  2  results achieved earlier.

No complaint at all ! -- but clearly all methods require some practice.
I've added your result to my I/net 'test' examples (I hope that's ok).

Any other suggestions are welcome -- apparently this is of interest -- ,
but I will turn to other priorities & investigate panoramas a bit later.

BTW the location is Steelhouse Lane with Snow Hill Sta in the background
(I stated it incorrectly before) in May 1953 just before the final trams.
The photo was taken with a Zeiss Ikon camera, a well-reputed make :
perhaps you can find the focal width on the I/net somewhere.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Michael Mol]

On Sat, May 19, 2012 at 12:38 AM, Philip Webb <purslow@ca.inter.net> wrote:
> 120518 Michael Mol wrote:
>> Remarkably simple. Probably because I was only stitching two photos.
>
> -- details snipped --
>
> Thanks : that gives me a 3rd method to pursue.
>
> NB in your result there are some badly curved lines :
> bottom right, the front of the tram is badly distorted ;
> centre top, the sides of buildings are curved outwards ;
> also, the bottom of the photo has been lost, eg the L-side man's eyes,
> & the result if smaller than the other  2  results achieved earlier.

It's inevitable that you're going to lose some of the image. That's a
function of reprojecting the stitched image.

The distortions are very probably due to an incorrect focal length
setting--something that's going to be impossible to get correct. But I
likely could have corrected by forcing Hugin to treat it like lens
aberrations, and getting it to correct for it that way. That would
indeed take a great deal of time.

>
> No complaint at all ! -- but clearly all methods require some practice.

The problem here is that there's missing source data. (Details below)

> I've added your result to my I/net 'test' examples (I hope that's ok).

np. I was going to share an ImageShack link, but I realized I wasn't
sure whether by "keep the image off-list" you meant "don't attach the
image" or "don't show the image on the list".

>
> Any other suggestions are welcome -- apparently this is of interest -- ,
> but I will turn to other priorities & investigate panoramas a bit later.
>
> BTW the location is Steelhouse Lane with Snow Hill Sta in the background
> (I stated it incorrectly before) in May 1953 just before the final trams.
> The photo was taken with a Zeiss Ikon camera, a well-reputed make :
> perhaps you can find the focal width on the I/net somewhere.

Now here's where the fun begins. According to Wikipedia, the Zeiss
Ikon is 35mm SLR...but that's about all you're going to get from it.

Really, everything else of interest is in the lens.

Being an SLR, the lens can (and will) be swapped out by the
photographer as circumstance demands. Each lens is going to have
different aberration characteristics, but that's not nearly as
important as the other difference: Without knowing the lens used, you
know next to nothing about the focal length and field of view. (The
two values can be derived from each other, as long as you know the
frame size...which we do.)

Worse, if the photographer was not using a prime lens[1], and was
instead using a lens with variable zoom, you can't easily know what
the real focal length was, as this will change depending on how far
the photographer has zoomed in. Now, I suppose that if you knew the
physical sizes of a couple fixed lines in each picture, where the two
lines were some not-insignificant distance apart, you may be able to
roughly calculate the focal length.

But, really, without knowing the focal length, getting the stitch
right is going to be guess-and-check.

Incidentally, this is one reason why digital photography is awesome.
Almost everything interesting you may need to know about the shot is
going to get stored in the EXIF data in the image files. My camera
stores the lens focal length at the time of snap; if I have a zoom
lens on, it records the exact focal length the lens happened to be on.
It's quite nice. :)

[1] This isn't "prime" as "excellent" or "high grade"..."prime" in
this context means it has a fixed focal length. It may have additional
implications, but that's the largest functional relevance: a "prime
lens" is a lens with a fixed focal length, a lens which doesn't have a
variable zoom capability.[2]

[2] I'm dribbling in a lot of semi-relevant technical stuff in here
for those who are following the thread for informational purposes.
-- 
:wq

Re: [gentoo-user] merging or fitting images together

[Stroller]

On 19 May 2012, at 20:28, Michael Mol wrote:
> … 
> Worse, if the photographer was not using a prime lens[1], and was
> instead using a lens with variable zoom, you can't easily know what
> the real focal length was, as this will change depending on how far
> the photographer has zoomed in. 

Throughout everything else you said I was thinking something like this.

Zoom lenses were much less common even 2 or 3 decades ago.

For a long time, a 50mm prime was the common kit lens, rather than the 18-105mm zoom which is sold today.

This was because, on a camera using 35mm film, a 50mm focal length gives a field of view very close to that seen naturally by the human eye. 

Wikipedia states that "the first modern film zoom lens was designed around 1950 by Roger Cuvillier" and Canon's official website (the "Canon Camera Museum" pages) states that "The history of Canon's zoom lens goes back to 1954."

Since the photos are stated go have been taken in 1953 it seems highly unlikely that the photographer was using a highly expensive and cutting-edge zoom lens. I doubt many people would have been able to afford these zoom lenses when they were first released. 

It seems to me safer to assume that the lens is a 50mm.

I guess focal length may change fractionally during focussing (as lenses are moved back and forth during as the focus ring is turned), however it may also be that a camera manufacturer designs a lens with a 48mm focal length (because that's easier to construct for some reason, or produces better images) and decides to sell it as 50mm because a 2mm difference in focal length makes no difference to the photographer. 

Or it may be that the distortion is caused by lens distortion - perhaps Hugin is trying to compensate for that, and straightening up lines. 

In any case, I might try re-doing the stitch a few times, each time telling Hugin the lens is 47mm, 48mm, 49mm, … 51mm, … 53mm. Perhaps you may find that one of those is perfectly spot on.

Stroller.

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120519 Michael Mol wrote:
> According to Wikipedia, the Zeiss Ikon is 35mm SLR,
> but that's about all you're going to get from it.

No ! -- as Stroller pointed out, zoom lenses were invented only c 1950.
My stepfather's model was made in Germany c 1939 
& had been mentioned to him as a good buy by a photo-expert friend.
After the traumas of England 1940, someone had sold it to a store,
which was offering it very cheaply, so he grabbed a very real bargain.
I didn't think of keeping it after he died, but it wb a collector's item:
I've put a photo I found on the I/net in my 'test' directory.

It didn't use  35 mm  film, but '120' IIRC, a much larger format.
What was a typical focal length for a good camera in 1939 ?

This thread, tho' rather far from Gentoo itself,
has obviously been of interest to a number of people
& can serve as a resource for anyone searching the I/net
for advice how to make a panorama from smaller images,
but we shouldn't take it too far & images themselves belong elsewhere.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120520 Stroller wrote:
> Zoom lenses were much less common even 2 or 3 decades ago.
> For a long time, a 50mm prime was the common kit lens,
> rather than the 18-105mm zoom which is sold today.
> This was because on a camera using 35mm film, a 50mm focal length
> gives a field of view very close to that seen naturally by the human eye. 
> Wikipedia states that "the first modern film zoom lens was designed c 1950
> by Roger Cuvillier" and Canon's official website (the "Canon Camera Museum")
> states that "The history of Canon's zoom lens goes back to 1954."
> Since the photos are stated go have been taken in 1953
> it seems highly unlikely that the photographer was using
> a highly expensive and cutting-edge zoom lens. I doubt many people
> would have been able to afford these zoom lenses when first released. 
> It seems to me safer to assume that the lens is a 50mm.

In fact, looking more closely at the picture of a ZI
which I've put up in my I/net 'test' dir (found on the I/net earlier),
it says 'F = 7,5 cm', so the lens appears to have been a  75 mm .

> I guess focal length may change fractionally during focussing
> -- as lenses are moved back and forth during as the focus ring is turned --
> however it may also be that a camera manufacturer designs a lens
> with a 48mm focal length because that's easier to construct for some reason
> or produces better images and decides to sell it as 50mm
> because a 2mm difference makes no difference to the photographer. 
> Or it may be that the distortion is caused by lens distortion
> perhaps Hugin is trying to compensate for that, and straightening up lines. 
> In any case, I might try re-doing the stitch a few times,
> each time telling Hugin the lens is 47mm, 48mm, 49mm, … 51mm, … 53mm.
> Perhaps you may find that one of those is perfectly spot on.

Thanks for the further lesson ! -- it sb tried at  75 mm .

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Michael Mol]

On Sat, May 19, 2012 at 10:01 PM, Stroller
<stroller@stellar.eclipse.co.uk> wrote:
>
> On 19 May 2012, at 20:28, Michael Mol wrote:
>> …
>> Worse, if the photographer was not using a prime lens[1], and was
>> instead using a lens with variable zoom, you can't easily know what
>> the real focal length was, as this will change depending on how far
>> the photographer has zoomed in.
>
> Throughout everything else you said I was thinking something like this.
>
> Zoom lenses were much less common even 2 or 3 decades ago.

Ah. Excellent point!

>
> For a long time, a 50mm prime was the common kit lens, rather than the 18-105mm zoom which is sold today.

18-105? I'm used to seeing 18-55.

>
> This was because, on a camera using 35mm film, a 50mm focal length gives a field of view very close to that seen naturally by the human eye.
>
> Wikipedia states that "the first modern film zoom lens was designed around 1950 by Roger Cuvillier" and Canon's official website (the "Canon Camera Museum" pages) states that "The history of Canon's zoom lens goes back to 1954."
>
> Since the photos are stated go have been taken in 1953 it seems highly unlikely that the photographer was using a highly expensive and cutting-edge zoom lens. I doubt many people would have been able to afford these zoom lenses when they were first released.
>
> It seems to me safer to assume that the lens is a 50mm.

Probably generally true. (Though as Philip later remarked, it turns
out the lens was likely a 75mm prime)

>
> I guess focal length may change fractionally during focussing (as lenses are moved back and forth during as the focus ring is turned), however it may also be that a camera manufacturer designs a lens with a 48mm focal length (because that's easier to construct for some reason, or produces better images) and decides to sell it as 50mm because a 2mm difference in focal length makes no difference to the photographer.
>
> Or it may be that the distortion is caused by lens distortion - perhaps Hugin is trying to compensate for that, and straightening up lines.

I don't think the 'Align' button in the wizard tries to optimize for
lens distortion...adjusting for lens distortion tends to take a fair
amount of time in terms of CPU, and far longer in terms of finding the
right sequence of control point optimizers, where an errant point
won't send the algorithm into mathematically weird territories.

>
> In any case, I might try re-doing the stitch a few times, each time telling Hugin the lens is 47mm, 48mm, 49mm, … 51mm, … 53mm. Perhaps you may find that one of those is perfectly spot on.

I tried it again, this time using 342 control points generated by
hugin-cpfinder and autopano-sift-c. (Several runs of the latter, with
100 points each, produces a good set of points). There wasn't anything
for celeste to pick  up, so I used the "fine-tune all points" tool,
and then cleared the thirteen or so points which didn't have good
correlation.

Following that, I ran the control point optimizer in "anchored,
positional mode", checked the preview, and then ran the "everything
without translation" control point optimizer. Checking the preview
again, the panorama was way off-center, so I dragged it back into
place using the fast preview window.

Following that, I ran the exposure optimizer's "low dynamic range"
preset. In the preview, things looked OK. The leftmost portion will
never look all that great, as he captured the sun setting behind a
building (or maybe that's a water spot); that narrowed the usable area
of the dynamic range of the frame, and it's going to look kinda
grayish. If these source JPG files are scans of paper photos, I could
do a lot more with a new scan set using 16bpp TIFF or OpenEXR, and at
perhaps 600 or 1200 dpi instead of 72 or so. Might be able to recover
more detail out out of that leftmost section.

Anyway, the final Hugin pto file is here: http://pastebin.com/gudxvAEa

And the final stitch is here:
http://img407.imageshack.us/img407/2030/brum3068brum30702.jpg

Interesting exercise! The image is still a bit smaller than my first
pass (704x407 vs 785x413), but it's not cropped as tightly, the lines
on the tram are much straighter, and most of the nasty noise on the
leftmost portion has been dealt with. There's likely something that
can be done to blow the image up a bit more.

-- 
:wq

Re: [gentoo-user] merging or fitting images together

[Philip Webb]

120520 Michael Mol wrote:
> as Philip later remarked, it turns out the lens was likely a 75mm prime

The picture of the camera looks exactly what I remember,
tho' there might have been different models with different lenses.
It was a very good camera for its time.

> The leftmost portion will never look all that great,
> as he captured the Sun setting behind a building
> or maybe that's a water spot

The Sun was indeed setting to the left at that time + date,
but the bluish blemish is some sort of physical decay in the negative,
which was stored in a cardboard box for  c 55 yr  without being touched.

> If these source JPG files are scans of paper photos

No, they're  2  overlapping scans of the same negative,
whose size is  58 x 43 mm  =  2,3 x 1,7 inch .

> Anyway, the final Hugin pto file is here: http://pastebin.com/gudxvAEa

What is a 'pto' file ? -- I downloaded it & it's text.

> And the final stitch is here:
> http://img407.imageshack.us/img407/2030/brum3068brum30702.jpg

All Firefox gives me is a black window : can you check ?

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] merging or fitting images together

[Michael Mol]

On Sun, May 20, 2012 at 8:33 PM, Philip Webb <purslow@ca.inter.net> wrote:
> 120520 Michael Mol wrote:
>> as Philip later remarked, it turns out the lens was likely a 75mm prime
>
> The picture of the camera looks exactly what I remember,
> tho' there might have been different models with different lenses.
> It was a very good camera for its time.

I'll say! Based on that pic, other things you've said, and the
information I found[1], that's an Ikonta 521 B with a Tessar f/3.5
lens, which appears to have been a high-end lens. Meanwhile, all of
the lenses for that camera appear to have been 75mm; the big
difference appears to be f-stop, which has an impact on
depth-of-field/bokeh. And an f/3.5 lens isn't something your modern
DSLR's kit lens can usually do.

[1] http://camerapedia.wikia.com/wiki/Zeiss_Ikon_Ikonta

>
>> The leftmost portion will never look all that great,
>> as he captured the Sun setting behind a building
>> or maybe that's a water spot
>
> The Sun was indeed setting to the left at that time + date,
> but the bluish blemish is some sort of physical decay in the negative,
> which was stored in a cardboard box for  c 55 yr  without being touched.
>
>> If these source JPG files are scans of paper photos
>
> No, they're  2  overlapping scans of the same negative,
> whose size is  58 x 43 mm  =  2,3 x 1,7 inch .

Ah. Well, the same holds true; a higher-resolution scan of the source
image, stored in an HDR image format (such as 16-bit-per-channel TIFF,
16-bit-per-channel PNG, or OpenEXR) would ultimately give better
results. Any of the 16-bit-per-channel formats would increase the
available dynamic range (of the format, at least) by a factor of 16,
at least. (IIRC, JPEG models luminance in 12 bits, and, for monochrome
images, that's at least somewhat advantageous over 8-bit-per-channel
grayscale or RGB formats.)

>
>> Anyway, the final Hugin pto file is here: http://pastebin.com/gudxvAEa
>
> What is a 'pto' file ? -- I downloaded it & it's text.

It's a Hugin project file; you can load that file with Hugin. It
assumes the two source JPEG files are in the same directory.

>
>> And the final stitch is here:
>> http://img407.imageshack.us/img407/2030/brum3068brum30702.jpg
>
> All Firefox gives me is a black window : can you check ?

Works on my system. It comes up all-black in geeqie, though; I had to
load it in Chrome. Also loads fine in Gimp 2.6.

-- 
:wq

Re: [gentoo-user] merging or fitting images together

[Stroller]

On 21 May 2012, at 02:06, Michael Mol wrote:
> ...
>> 
>>> And the final stitch is here:
>>> http://img407.imageshack.us/img407/2030/brum3068brum30702.jpg
>> 
>> All Firefox gives me is a black window : can you check ?
> 
> Works on my system. It comes up all-black in geeqie, though; I had to
> load it in Chrome. Also loads fine in Gimp 2.6.

Blank here, too, in Mac Safari and if I download it and open in Preview.app

I can convert it to a .bmp using ImageMagick, however - what a wonderful result!

(This raises a thought - Philip might be best working entirely in .bmp or .tiff, having Hugin spit out .bmp or .tiff results and saving those as his "best quality" conversion for archive purposes. Then converting to .jpeg after that). 

Stroller.

Re: [gentoo-user] merging or fitting images together

[Michael Mol]

On Mon, May 21, 2012 at 12:09 PM, Stroller
<stroller@stellar.eclipse.co.uk> wrote:
>
> On 21 May 2012, at 02:06, Michael Mol wrote:
>> ...
>>>
>>>> And the final stitch is here:
>>>> http://img407.imageshack.us/img407/2030/brum3068brum30702.jpg
>>>
>>> All Firefox gives me is a black window : can you check ?
>>
>> Works on my system. It comes up all-black in geeqie, though; I had to
>> load it in Chrome. Also loads fine in Gimp 2.6.
>
> Blank here, too, in Mac Safari and if I download it and open in Preview.app
>
> I can convert it to a .bmp using ImageMagick, however - what a wonderful result!

I'm seriously wondering if there might not be something broken with
the .jpeg files I'm spitting out. That laptop (saffron) is in the
middle of an overdue emerge --update --deep --newuse @world, though.
(And I saw it was complaining about 19 blockers...) It may be overdue
for a depclean and some other maintenance. I haven't tweaked things
much, as it's my last functioning Gentoo box until I get kaylee and
inara fixed.

>
> (This raises a thought - Philip might be best working entirely in .bmp or .tiff, having Hugin spit out .bmp or .tiff results and saving those as his "best quality" conversion for archive purposes. Then converting to .jpeg after that).

Don't know much about his current process, so there's not a whole lot
of recommendations one could make. But it's definitely an interesting
problem!

-- 
:wq

Re: [gentoo-user] merging or fitting images together

[Michael Mol]

On Mon, May 21, 2012 at 12:31 PM, Michael Mol <mikemol@gmail.com> wrote:

[snip]

> I'm seriously wondering if there might not be something broken with
> the .jpeg files I'm spitting out. That laptop (saffron) is in the
> middle of an overdue emerge --update --deep --newuse @world, though.
> (And I saw it was complaining about 19 blockers...) It may be overdue
> for a depclean and some other maintenance. I haven't tweaked things
> much, as it's my last functioning Gentoo box until I get kaylee and
> inara fixed.

Yeah, Windows Photo Viewer says "Windows Photo Viewer can't open this
picture because the file appears to be damaged, corrupted, or is too
large." Certainly not too large. I'd have to step through some
decoder's processing of the image to see what's broken about it.

-- 
:wq

Re: [gentoo-user] merging or fitting images together

[Paul Hartman]

On Mon, May 21, 2012 at 11:31 AM, Michael Mol <mikemol@gmail.com> wrote:
>
> I'm seriously wondering if there might not be something broken with
> the .jpeg files I'm spitting out. That laptop (saffron) is in the
> middle of an overdue emerge --update --deep --newuse @world, though.
> (And I saw it was complaining about 19 blockers...) It may be overdue
> for a depclean and some other maintenance. I haven't tweaked things
> much, as it's my last functioning Gentoo box until I get kaylee and
> inara fixed.

It looks like the file uses arithmetic coding, which has legal
restrictions (patents, licensing, blah), which means many jpeg
implementations do not support it. That probably is why it works in
some places and not in others. You should pretty much always use
Huffman coding instead of Arithmetic coding if you're using the images
on the internet or sharing them with others. The image quality is not
affected by this choice, only the way the data is stored in the file.
The file size will be slightly larger using Huffman, but in most cases
only barely larger.

Re: [gentoo-user] merging or fitting images together

[Michael Mol]

On Mon, May 21, 2012 at 12:57 PM, Paul Hartman
<paul.hartman+gentoo@gmail.com> wrote:
> On Mon, May 21, 2012 at 11:31 AM, Michael Mol <mikemol@gmail.com> wrote:
>>
>> I'm seriously wondering if there might not be something broken with
>> the .jpeg files I'm spitting out. That laptop (saffron) is in the
>> middle of an overdue emerge --update --deep --newuse @world, though.
>> (And I saw it was complaining about 19 blockers...) It may be overdue
>> for a depclean and some other maintenance. I haven't tweaked things
>> much, as it's my last functioning Gentoo box until I get kaylee and
>> inara fixed.
>
> It looks like the file uses arithmetic coding, which has legal
> restrictions (patents, licensing, blah), which means many jpeg
> implementations do not support it. That probably is why it works in
> some places and not in others. You should pretty much always use
> Huffman coding instead of Arithmetic coding if you're using the images
> on the internet or sharing them with others. The image quality is not
> affected by this choice, only the way the data is stored in the file.
> The file size will be slightly larger using Huffman, but in most cases
> only barely larger.

I'm familiar with the difference between Huffman and arithmetic[1]. I
don't recall seeing any options for managing it, though. I'd have to
check to find out what USE flags I've got enabled that might be
involved. Also surprising that Windows 7 won't process it.

[1] Side effect of having a crazy compression geek for a friend and
coworker. I think he finally got around to trying my suggestion of
saving off the deflate window state for seekable .tar.gz files.
-- 
:wq